Around 5 a.m. on Tuesday, October 17, French ultrarunner François D’Haene arrived at the northernmost point of the John Muir Trail just two days, 19 hours, and 26 minutes after departing from the trail’s southern terminus. In doing so, the 31-year-old set a new supported Fastest Known Time on the iconic trail that traverses eastern California’s Sierra Mountains. His effort shattered Leor Pantilat’s 2014 record of three days, seven hours, and 36 minutes. 

D’Haene began on Saturday morning at the base of 14,505-foot Mount Whitney and continued north to Happy Isles in Yosemite Valley. In total, the trail climbs more than 47,000 vertical feet, and winds through extremely remote sections of Sequoia, Kings Canyon, and Yosemite National Parks. D’Haene was gifted with clear, cool fall conditions for all three days—a rarity given the height and exposure of the JMT that often results in extreme heat—and team of Salomon crew members who met him at various points along the trail with food, water, supplies, and a bed for temporary naps. 

The record-setting run comes just over a month and half after D’Haene won the prestigious and highly competitive Ultra-Trail du Mont-Blanc—a 103-mile race with over 30,000 feet of elevation gain—for the third time. Over the last five years, D’Haene has established himself as one of the world’s most dominant mountain runners. “He’s the best in the world at anything over 50 miles,” says Mike Wolfe, a North Face ultrarunner who had previously set the record in 2013. “I’m not surprised that he crushed it.”

The John Muir Trail tops the bucket list for many ambitious ultraunners due to the combination of its relatively manageable distance and challenging, high-alpine conditions. The trail has a rich history of notable FKT record-setters over the past 15 years, including elite runners Peter Bakwin, Hal Koerner, Brett Maune, and Wolfe. With D’Haene’s most recent dominance, it may be some time until we see a new name at the top of that list.

If you’re as old as I am, you might remember a mid-1990s commercial in which a smug jock challenges Jason Alexander to back up his claims of pretzel-fueled physical prowess: “Prove it, pretzel boy!” Alexander proceeds to shimmy up a rope, win a wrestling match, and execute a dazzling gymnastics floor routine—definitive proof that fat-free Rold Gold pretzels really are performance enhancing.

That commercial is a pretty good illustration of what the Sweat Science column is not (or at least, what it aspires not to be).

I’ve been writing about the science of endurance, fitness, and health for about a decade. I’m interested in figuring out what works and what doesn’t, what we know and what we don’t, and how we tell the difference. When I started out in the field, my articles looked a lot like that Rold Gold commercial. Want to know how to fuel for a marathon? Call up a few really fast marathoners and ask what they do. Looking for advice on how to buy the perfect running shoe? Call a shoe company and get them to explain it.

To be clear, there’s a lot of value in the advice you get from experienced experts. But there are also blind spots. Even leaving aside the distorting effect of sponsorship dollars, it’s almost impossible for a single individual to isolate the factors that have improved their own health or performance. As physicist Richard Feynman said, “The first principle is that you must not fool yourself—and you are the easiest person to fool.”

So that’s pretty much the prime directive for Sweat Science: explore the science of endurance and adventure, but without fooling myself (or you). Mostly, that means following the peer-reviewed literature on these topics, deconstructing the findings, and, wherever possible, sharing and explaining the key data and graphs. Not all studies are created equal, of course—but if I explain the methodology and findings clearly enough, you’ll be able to make up your own mind about what they tell us, rather than relying on my say-so.

That means I’m not a product reviewer. I love shiny new gear as much as the next guy, and I think there’s an important place for subjective reviews. But that’s not my role. Whether an amazing new cooling shirt fits perfectly or a new sports drink tastes amazing—those are different questions than whether the shirt really cools you or the drink really makes you faster. I think I do a better job at the latter questions if I don’t have an opinion on the former.

It also means I sometimes won’t have much to say about the newest trend or the hottest product. I receive a steady of flood of PR pitches for products and programs promising everything under the sun. Sometimes, if my interest is piqued, I write back and ask if they have any experimental data, preferably peer-reviewed, to support their claims. I almost never hear back—or rather, I hear back with offers to put me in touch with the inventor or a satisfied (and sponsored) client, neither of which is what I was asking for.

The Sweat Science column has existed in various incarnations for nearly a decade, first as a standalone blog, then, from 2012 to 2017, as a Runner’s World column. The move to Outside is exciting for a few reasons—mostly because it gives me a chance to broaden the column’s focus to something that more closely reflects my own current interests. I come from a running background and will continue to write about that, but I also enjoy other activities like cycling and cross-country skiing, have recently gotten into rock climbing, and love hiking and canoe trips. I’m looking forward to drilling into the science of these and other activities in the coming months—starting with this look at a new study on the unexpected physiology of backpack hip straps.

In its new Outside incarnation, Sweat Science will also take more deep dives, providing context and focusing on the big picture, instead of chasing the latest results of an isolated study. And I’ll be doing more of my own number-crunching and data analysis, like this piece comparing trends in world record frequency at different running distances over time.

In the end, I don’t believe science can tell us everything we need to know about endurance. If anything, a decade of Sweat Science has taught me how little we understand and how much of our current knowledge has been accumulated by painstaking trial and error. But science can give us a reality check on entrenched assumptions and protect us from overhyping unproven new ideas—and, aside from “practical takeaways,” it can offer some fascinating flashes of insight about what’s really going on in your body and mind when you’re pushing your limits.

So I hope you enjoy the column—I’d love to hear your thoughts, questions, and (if you must!) criticism. You can read the latest posts here, connect with me on Twitter and Facebook, and sign up for email updates here.

There’s a George Carlin bit called “Fussy Eater” in which the late comedian riffs on the idea that some foods are unappetizing because they have questionable names. (For example, squash: “It sounds like somebody sat on my dinner.”) Of course, it’s hardly a secret that certain language can trigger a specific emotional response. Environmentalists have lamented that “climate change” sounds too innocuous to stir people into action. Meanwhile, branding gurus earn a living by dreaming up evocative names so you’ll buy a particular kind of pickup truck or yogurt.

Perhaps some of these language wizards can help the sport of distance running improve its messaging—especially since the “running boom” has been ebbing over the past few years. At the very least, we should consider excising the following words from the sport’s lexicon.


There shouldn’t really be any debate on this one. Standing in the midst thousands of nervous, pungent strangers before setting out on an orchestrated stampede is unnerving enough without an explicit livestock reference. The Gold Coast Marathon in Australia uses the term “start zone.” Much more dignified.


Every time I meet up with my local running group, someone will inevitably refer to their weekly or monthly mileage when discussing their training routine. As with “corral,” “mileage” has a dehumanizing effect. It’s not great for motivation; I may be alone here, but I don’t fancy talking about myself as if I were a used Subaru. “Modern exercise makes you acknowledge the machine operating inside yourself,” Mark Greif wrote in a 2004 essay for n+1 that reads as a caustic take on the hollowness of contemporary fitness culture. “Mileage” is a case in point.


Obviously, we can’t lament the pervasiveness of “mileage” and let “fuel” and “fueling” off the hook. The machine analogy persists! Also, since eating is one of life’s principal joys, it seems advisable not to describe running-related consumption habits with a word connoting gasoline. To be fair, I can understand the tendency to think of in-race sustenance as fuel, rather than food; at the end of the day, the gel packet you sloppily imbibe at mile 23 doesn’t have much in common with mom’s home cooking. Still, I think we can do better. Is “competition foodstuffs” too much of a mouthful? Probably.


Apropos of foodstuffs: There’s something vaguely disgusting about the expression used to describe the process of consuming copious amounts of carbohydrates, typically during the week leading up to a big race. Imagine if you knew nothing about running and, after a bit of preliminary research, found out that “carbo-loading” was a widespread practice. Does that seem like a culture you’d want to be a part of? Carbo-loading sounds like an unpleasant form of forced gluttony. My vote is for a verbified iteration of “pastapalooza.”

(Race) Bib

Growing up, I spoke German before I spoke English. Even though I consider myself reasonably proficient in the latter language by now, occasionally there are moments that make me have my doubts. Like when I’m at a race expo and a volunteer informs me where I can pick up my bib. Excuse me? (I thought this was a ten-miler, not an all-you-can-eat seafood buffet?) I’m probably being overly sensitive here, but it’s my understanding that most people, when they hear “bib,” think of a mealtime accessory for babies. Seems less than ideal for road race organizers who want to create an atmosphere of serious competition.

Endurance sports have a problem with overuse injuries. The stats are sobering: as many as 75 percent of runners will be injured in a given year. Many of those will come as a result of excessive and repetitive pressure on joints, muscles, ligaments, and tendons, according to a survey by Harvard Medical School. These injuries can sideline athletes for months on end, and permanently impact their capacity to perform. 

You’ll never be totally safeguarded from possible injury; but you can take some preemptive action that might make falling victim to overuse far less likely, and develop an eye for warning signs to catch them early before they become a real problem. Follow these guidelines to make sure you’re doing all that you can to protect yourself.

#1. Always Be Moving 

Though overuse injuries may appear suddenly, they’re actually a result of strain or stress building up over the course of days or even weeks. This accumulation of micro-traumas doesn’t just happen during exercise. Things like sitting at a desk all day or commuting long hours in a car can contribute to burgeoning back, neck, and hip injuries.

“We adapt to what we do,” says Jay Dicharry, a physical therapist and expert in endurance sport biomechanics based in Bend, Oregon. “And our lifestyle is constantly training our bodies, sometimes for the worse.” To avoid the repetition that leads to overworked muscles and joints, incorporate a bunch of different movements into your day. Sit, stand, walk, stretch—whatever you do, just move regularly. 

#2. Strength Train Year-Round

Despite a significant uptick in endurance athletes who swear by their strength work, some people still believe that their weightlifting should halt once they enter their competitive season. That’s not the case. A 2015 study found that when elite cyclists stopped their strength training program for the first eight weeks of a competition period, their performance declined. What’s more, Reed Ferber, an assistant professor of kinesiology and head of the Running Injury Clinic at the University of Calgary, says that his clinic has treated 92 percent of the knee injuries it sees through a strength routine focused on building muscle and mobility in the hips. 

The key is to keep up the strength work, but to stop doing it 72 hours before a race to allow the muscles time to fully recover, Dicharry says. It’s a strategy echoed by Michael Fredericson, musculoskeletal physiatrist and director of the Stanford Runner’s Injury Clinic. “Strength training should evolve over a competitive season but not stop,” he says. “Closer to competition, athletes should decrease the number of sets and reps, thinking less about endurance and more about explosiveness.”

#3. Fix Your Gait

A tell-tale sign of an overuse injury is a change in stride—some part of your body can no longer do what you’re asking it to do, so a different part picks up the slack, creating a limp. 

For example, those with ankle or Achilles pain often don’t use their calf to push the heel off the ground when running. That type of compensation can both reinforce muscle weakness and joint stiffness and create problems elsewhere, as other parts of the body are repeatedly asked to do a greater share of the work. It’s one reason why the leading risk factor for these conditions is previous injury. 

The only way to fix the issue is to re-train your body to execute the movement, specifically targeting the flaws in form. Even if you don’t have access to a biomechanics lab, apps like RunMatic and Saucony Stride Lab offer smart phone camera-based gait analysis. They’re designed to capture irregular movements and more severe imbalances, and provide recommendations and exercises on how to correct the problems.

#4. Focus on the Whole Body

The posterior chain—mainly your glutes, hamstrings, and lower back—has gained a reputation as the oft-neglected muscle group that’s responsible for many problems in the lower half of the body such as IT band, achilles, and knee or hip issues. While that’s true, putting in extra work to strengthen only your backside neglects other muscles groups like the quad, creating more imbalances. Strengthening your entire body is important for both treating and preventing injury, says Fredericson. 

#5. Rest the Right Way

Barring an acute injury or surgery, total rest—a sequence of days without any physical activity—won’t do you any favors, says Fredericson. On the other hand, relative rest—trading in your usual sport for cross-training or light activity—allows your body to restore hard-working muscles and joints without going totally dormant. 

While you should give stressed joints, tendons, and muscles the time to heal, it’s equally important to use the help of a PT or orthopedic doctor to correct the strength, mobility, and mechanical issues that caused the injury in the first place. Otherwise, those same problems might re-appear after a rest period.  

#6. Eat Enough Calories

The Female Athlete Triad of low bodyweight, low bone density, and hormonal imbalance impacts as many as 60 percent of female exercisers every year. In the case of the Stanford cross-country team, 38 percent of female runners developed stress fractures over a three-year period because of the problem, says Fredericson. But the issue doesn’t stop with women. Fredericson and other researchers have discovered many of the same imbalances in male runners—inadequate nutrition, low testosterone, and low bone density. All of these factors greatly increase the risk of injury.

When your body isn’t getting enough calories, it stops producing normal levels of testosterone and estrogen, leading to hormonal dysfunction. Because your growth hormone levels go down, muscle mass decreases, which in turn lowers the metabolism and leads to lower bone density. That combined with the pounding that comes from high levels of activity can result in a stress fracture, a problem that takes months to heal.

Fredericson’s research explores how a change in diet can greatly alleviate these risk factors. Put simply: endurance athletes need to eat more calories. Focus on eating a balanced diet and listening to your body’s hunger cues, especially on days where you’re working extra hard. If you struggle to know what that looks like, reach out to a sports nutritionist to help you develop a sound strategy.

“A little public-service announcement,” declares off-road riding legend Rebecca Rusch, also sometimes known as “the Queen of Pain.” My childhood buddy Adam Willner and I lean in, along with perhaps 200 other cyclists. We’ve each traveled many hundreds of miles—I’ve come from Texas, Adam from California—in the name of two-wheeled adventure and affirming 40 years of friendship on this September weekend. Tomorrow we’ll ride an off-road challenge, which Rusch unabashedly calls Rebecca’s Private Idaho (RPI). The particularly masochistic, century-length option that we’ve chosen is appropriately branded the “Big Potato.”

The Masters Athlete

Who says the young guns get to have all the fun? In this column, we tell the stories of athletes living full, fit, high-performance lives—and for whom age is really just a number.

Read all the stories

Standing at the foot of a pretty Idaho meadow, Rusch faces a gathering of RPI participants who’ve opted to attend the Saturday pre-ride. We’re taking a break halfway through the 20-mile, out-and-back workout, and Rusch is bent over a beast of a road bike, and giving welcome guidance. Adam and I, and no doubt many in the helmeted tribe all around us, may know plenty about cycling. But the two of us can talk a sliver of nothing about the form of riding known as gravel grinding, which we’ll be doing, for many hot and dusty miles, within 24 hours. We’re grinder rookies, and we’re learning that, in the simplest of terms, gravel grinding is road riding on everything but road.

“It’s a lot more secure and safe to descend in your drops. You’re all tucked in,” says Rusch, flexing her forged arms so that she can wedge her hands into the curves of road-bike style handlebars. The bike underneath her has, for a road-type bike anyway, supremely fat and knobby tires, as well as disc brakes. All standard gravel-grinding fare. “If you’re descending up here on washboards and going super-fast?” she says, tapping on the tops of the handlebars. “You have a lot more opportunities to come off.”

Rusch says that the final, bumpy, 1,500-foot, dirt-and-dust descent ahead of the finish lacks a guardrail, and that the drop-off is sometimes 1,000 feet. 

“You know, it’s narrow,” she adds. 

Welcome to the kind of stupid-great adventure that two young-thinking but old and nostalgic pals might embark on. RPI, which is in its fifth year and climbs over 5,000 feet across nearly 94 miles through south-central Idaho’s Pioneer Mountains, initially felt far more doable and digestible to a couple of bike-loving friends than, say, a weeklong Ride the Rockies. Adam and I figured that we’d frame a bro weekend in Idaho’s mountainous Ketchum and Sun Valley terrain around RPI. When we weren’t on our saddles, we’d kick back at the condo, or feed at some oft-Yelped, quaint eatery. On the continuum of BFF reunions, we thought that this one would lean closer to a spa weekend than to Deliverance.

But then the gravel reared its head.

A day earlier and on Adam’s and my first Idaho ride together, we’d loaded up on a Mexican lunch, pulled on spandex, and grabbed our bikes. We agreed to pedal at an easy pace on one of the many dirt roads leading from town and then… we suffered. Our lungs, which live a lot closer to sea level than Ketchum’s 6,000 feet, groped for oxygen. Our 52-year-old legs felt wooden on a climb that didn’t ease much over 10 miles.

The worst, however, was yet to come. The last time I’d descended miles of dirt on a suspension-free bike, the Berlin Wall remained upright. Even in the 1980s, I was still riding dirt on a truly fat-tired mountain bike. In Idaho, on the other hand, I was on my new, rugged aluminum cyclocross bike, which I’d fitted with oversize tires and extra-low gearing, specifically for RPI. A mechanic at my local shop called my ride a “Frankenbike.” It was expensive, too. But hey: Can you put a price on lifelong friendship?

Frankenbike, cyclocross bike, whatever—the dirt-road descent seized up my shoulder blades and hands. My ligaments and muscles shook like dice in a cup. Adam, on his new carbon-fiber gravel grinder, fared no better. By the time we reached pavement, I felt that a couple of aging athletes were about 20 years too late for the moment.

A day later, and with Adam and I still smarting, Rusch concluded her public service announcement by telling us and the rest of the pre-ride crowd to rest up ahead of tomorrow’s RPI. Rather matter-of-factly, she told us that if we wanted to be Big Potatoes by day’s end, we’d need to suck it up.

Persistent shoulder pain or no, I still felt overwhelmingly happy. The love and understanding of an old friend is one of life’s most glorious intangibles. You can’t put a metric on, say, the soothing feel of cool dew meeting bare feet on a crisp morning. Or how great it is to watch your dog go legs-up on a patch of grass, and zealously roll and roll on its back. 

The same kind of joy comes from a friend gently laughing at you when you get frustrated—as you did in his company 35 years ago while you were traveling abroad together, when he watched as you pushed back on a prickly inn-keeper over the money spent for a dumpy room in Brixton—because you’re burning through all the zip-ties while wrongly fastening your racing chip to your bike fork. Doesn’t really matter that you’re no longer a teenager. 

“Drew, it’ll be OK,” he says with a chuckle as I fume over a job poorly done. “We’ll get more zip-ties back at the packet pickup tables.”

Adam is gray-haired but still ever cheerful, with a round, unlined face that defies the weight of life encountered by so many of us in middle age. Adam also looks about as lean and strong as he did when we met as freshmen at San Francisco University High School back in the fall of 1979. And where he once was an entrepreneurial restaurateur who only occasionally found time to ride, Adam and his wife, Marta, are now nearly empty nesters. Over the last decade he’s gone from cycling enthusiast to mileage monster while thriving as a father, chef, and host. In 2017 alone, my friend has ridden three organized 200-mile rides. 

andrew tilin
(Courtesy Andrew Tilin)

I’ve been riding since I was 18, and my three oldest friends in the world have each been part of the journey. In my early 20s, I toured across Europe with Dave Rosenthal. I raced bikes all over the west with Peter Wood in my 30s and 40s. Now on a brisk Idaho morning in summer 2017, Adam and I were about to pile more stories onto a friendship that already included memories of high-school parties, weddings, births of children, and celebrations of families and careers. Adam and I fasten our helmet straps before walking out the condo door.

Glorious intangibles. Adam’s cleats click into place, and I watch as my longtime friend takes his first pedal strokes toward the RPI start line.

Soon, after almost 1,000 riders bow their heads in downtown Ketchum for “America the Beautiful,” I do what any compulsive, longtime, self-important bike racer does: I drop all the riders that I can, including my best friend. The four-mile dirt climb up Trail Creek Road near the start of RPI plays to my scrawny frame, and my often short but intense training. Adam, whose natural bulk steered him to play lacrosse in high school, still has 40 pounds on me. 

“Hey, Texas,” Adam says as he comes up behind me, two-thirds of the way to Trail Creek’s 7,800-foot summit. “Nice riding.”

Even though we haven’t hatched a genuine strategy for RPI, Adam and I both understand that the day’s priority is to take on the ride, and the bumps and dirt and heat, together. Sure, some participants race RPI. Former Tour de France rider Ted King is among RPI’s entrants. No doubt he’s already many miles ahead of us.

The top of the climb brings several rewards. At the pass a huge and beautiful basin inside the Sawtooth National Forest, which includes broad peaks, open grassland, and clusters of evergreens, lays ahead of us. Maybe best of all, the endless bumps and ripples of the Trail Creek climb give way to extended stretches of smooth and fast dirt.

Adam looks over his shoulder as I push myself to stay on his wheel. Clearly he’s enjoying the flat and rolling terrain. “Like pavement!” he yells, and for maybe nine miles we often find ourselves grouped with other riders and riding roadie style. We draft, and take pulls leading others.

We also owe some gratitude to our tires, or more specifically our tire pressures. Gravel grinders obsess over tire firmness the way Taylor Swift sweats shades of red lipstick. Too much air in gravel grinder tires and you’ll feel every pebble. Too little and you might flat, as the tire deforms on big hits and either pinches a hole in your tube or perhaps, on tubeless tires, causes a sidewall to tear. But get the air pressure just right and a fat gravel grinder tire provides a happy blend of speed, traction, and shock absorption. Adam and I had picked up some intel during the pre-ride: run our tires at 30 to 40 pounds per square inch (PSI), which represented a lot less air than we’d used for our first two days of Idaho riding.

andrew tilin
(Courtesy Andrew Tilin)

RPI is going great—our legs humming, our asses and hands retaining sensation—when, about 35 miles into the ride and on the thick gravel of East Fork Road, the ride gets better. None other than Rusch latches onto our group of eight.

“That a way, ladies, looking strong,” says Rusch to the four women among us. She’s all smiles under her Red Bull helmet. “Keep rotating off the front.”

Rusch is chatty, pulling out of the slipstream in order to ride alongside me. Only one of us fights for breath as we talk, and it’s not the woman who owns a first (female) ascent on Yosemite’s El Capitan, once raced for top international adventure-racing teams, and has won the Leadville Trail 100 MTB (100-mile) mountain-bike race four times during a career as an outdoor athlete that has spanned decades.

“Several years ago, one of my sponsors told me: you have to go do this event in Kansas,” says Rusch, referring to gravel grinding’s iconic race, the Dirty Kanza 200. “I thought, that sounds heinous. I’m a mountain biker. That will be death by boredom.”

But Rusch loved how the 200-mile race meshed the demands of riding on- and off-road. She’s now won the DK200 three times. “The technical aspects of the uneven surfaces felt a lot more like mountain biking than road riding,” she says as my bike steers nervously and only semi-straight through 50 yards of deep gravel. “Someone couldn’t just ride in a pack and then outsprint you for a win.”

Rusch brought RPI to her adopted hometown of Ketchum in 2013, and precisely because she’s the Queen of Pain, Rusch believes that she’s attracted a disproportionately large chunk of female riders (about 30 percent). It’s also no accident that gravel grinding in general and RPI specifically (average race age: 46) bring out many older athletes who are a lot like me and Adam: aging riders who don’t always want to tangle with traffic or with hard-charging pelotons in Gran Fondos or road races. Instead we’re finding fun riding squirrelly road bikes over dirt, while trying to win one more bout of rider-versus-the-elements.

RPI remains fun even after Rusch is long gone, and Adam and I are a little more than halfway done. Then I get a flat.

What does a real friend do when you’re hot, dirty, thirsty, and watching your new, $55, tubeless front tire that had been filled to exactly the right PSI continue to seep goopy sealant, and air, courtesy of a sidewall tear? He pumps. He pumps like a madman.

“Drew, maybe we can keep it filled long enough to reach the next rest stop,” says Adam, his whole body moving like a piston in time with the hand pump that’s breathing a little life into my tire. “I don’t think we’re terribly far away.”

My shoulder blades had already been tingling for a while, and my hands were tired. An uncomplaining, salt-stained Adam can’t be feeling much better. I don’t know how he’s able to pump so furiously. 

“OK, bud. Thank you,” I say, lifting my leg over my bike’s frame. “Let’s try it.”

Slowly and now literally feeling every seam in the dirt, Adam and I creep for miles before we reach the aid station. When we leave, my mortally wounded front tire is now armed with a tube, with an empty energy-gel wrapper acting as a liner at the place of the tear. In the hopes of reaching the finish line, the tire now has the qualities of a taut balloon: it’s extra-firm in order to best avoid flatting again.

andrew tilin
(Courtesy Andrew Tilin)

For several miles of riding over washboard road and sloppy gravel, the Frankenbike resembles a jackhammer. Nerves in my neck and upper back feel like they’re aflame. I quietly throw myself a pity party. This is the dumbest fucking sport ever, I say to myself. What fool rides 100 off-road miles on a bike that’s as stiff as an I-beam?

A short while later, I notice that Adam is slowing. He keeps changing gears, which likely means he’s searching for a pedaling cadence that will deliver less pain to his legs. He drinks a lot from his bottles.

Now my friend needs a friend, and that notion thoroughly invigorates me. I catch Adam’s eye and point to my rear wheel. As instructed, he lines up his bike behind mine. 

The road rolls up and down. The gravel goes from soupy to nonexistent to soupy again. Bumps come and go, pickup trucks pulling fifth wheels cover us with more Idaho dust, and two exceptionally large deer—maybe they’re elk, honestly we’re too tired to tell—sprint across the road just ahead of us. The final, 1,500-foot, dirt plummet back to the outskirts of Ketchum is insultingly painful, a true violation of my body’s connective tissue best handled by—yes, Rebecca Rusch—staying low in my handlebars. Adam regains strength and takes the lead, and after seven taxing hours, we finish what we’d started. We are “Big Potatoes,” and only two-and-a-half hours behind winner Ted King.

In Ketchum, Adam and I unfold our bodies off our bikes, and soon thereafter, drink beer and eat grilled cheese-and-bacon sandwiches. Then we eat hamburgers and fries. Then we buy two pints of ice cream.

“You know, I thought about Advil a lot,” Adam says back at the condo, between spoonfuls of our cold and creamy, salted-caramel reward. “I mean, that descent was not comfortable, or fun. It wasn’t scary so much as something to just endure.”

He swallows one more bite of ice cream. “But weren’t those some great views?” he asks. 

One morning, in the spring of 2011, I was pool running in Berkeley, California. As I bobbed through the water, I watched the morning light creep over the hills. The predawn air was dank and chilly. Above the pool, fog rolled off San Francisco Bay, splashing against the hills like aerial sewage. When it’s especially foggy in the Bay Area, the sun doesn’t rise. Instead, it smudges into the sky in a monochrome blur.

At least, this was my grim perspective from the pool. I was groggy and uncomfortable. I felt ridiculous, pumping my legs in a maniacal facsimile of running, tepid water occasionally splashing into my mouth. The visceral urge to stay fit despite the injury was enough to get me into the pool. But I still wondered, “Why is cross-training so awful?”

Six weeks earlier, I had broken my foot while running on the Northern California trails. It happened suddenly: One moment, I was whipping through the woods, contemplating lunch. The next, I could barely walk. I limped the last three miles back to my car, pain shooting through my foot with every step. I had never broken a bone before; I figured it was just some bad tendonitis.

It was still painful a week later. Eventually, an X-ray revealed that I had completely broken my second metatarsal. The bone was displaced; the fractured ends skewed away from each other. And so I found myself cross-training.

Injuries are often heart-wrenching. The pain of physical trauma is often matched by the social and psychic toll that comes from losing your daily routine and training friends. And the effort to cling to your fitness through cross-training can feel like salt in the wound. Of all the ways to cross-train when injured, I truly loathe pool running. I dislike tinkering with flotation belts, goggles, and garishly colored Speedos. I hate the smell of chlorine and that initial shock of cold water engulfing your genitals.

Of course, there are other cross-training options for the injured runner. Most of these involve joining a gym filled with very different athletes than are found on running trails, tracks, and roads. Muscle-bound lifters moan over free weights. Instructors in bright spandex shout microphoned imperatives. There is a different vocabulary in gym: “cardio,” “Zercher squats,” and whatever the CrossFit people are saying these days. Above it all, fluorescent lights illuminate rows of exercise machines propping up sweaty bodies transfixed to their smartphones.

One can hardly blame folks for distracting themselves on exercise machines. Hopping onto a stationary bike or elliptical can be absolutely mind-numbing. Yet the static boredom of exercising indoors doesn’t fully explain, for me, why cross-training is so terrible. While many dislike the monotony of a treadmill, I don’t mind it that much. It’s not too different from running intervals around a track or jogging at night. I can achieve a meditative headspace. Even on a treadmill, the sport provides more than fitness. It offers a sense of direction, even when I’m running in place.

So while there are differences in scenery and company, the most unsettling part of cross-training is the deferred sense of purpose. Cross-training, especially when we’re injured, forces us to dramatically shift our reason for training. We must adopt a maintenance mindset. Injury usually necessitates that runners stop thinking about improvement or forward progress. Forced by circumstance into a position of preservation, the cross-training runner no longer works toward new goals or a better self. Training becomes mere exercise, a fight against our deteriorating fitness—a desperate struggle against entropy. Cross-training is about becoming less lesser; it’s about treading water, or breaking even.

People quip that the quickest way to the funeral home is through retirement. Take away a person’s sense of purpose, a reason to wake up in the morning, and eventually they stop waking up. Running is no different. Cut off progress toward an end, and activity becomes much more difficult.

One day, during the 2011 injury, I was overwhelmed by questions of purpose. I was again in the pool. It was another gray day, but this time the skies opened, and it began to rain. As cold drops of water clapped onto my head, I wondered aloud, “Why in the world am I doing this? How is this making me a better runner?” Beyond the pool, I noticed my shower towel was soaked. I’d be damp for the rest of the morning. “Fuck it.” I got out of the pool and limped to the locker room, wet towel in hand. It was a few days before I worked up the motivation to return to the gym.

Given the choice, I’ll always opt for a run. I’ve had many more injuries since 2011, and they remain frustrating. I’ve broken more bones, inflamed more tendons, and strained more muscles. But with experience comes perspective, and I’ve worked over the years to be less cynical about substitute activities. Movement is itself a privilege.

This past summer, I fractured a rib from a tumble in a trail race. After a couple weeks of total rest, I spent a few sessions on a spin bike to ease my legs back into activity. It wasn’t fun; I was bored after a single hour in the saddle. But as I spun my legs and even cranked up the resistance to dance on the pedals a bit, I had to admit that it was pleasant just to put my legs into motion.

Every day of the past five months, as I’ve made my way through 2,000 miles of the Pacific Crest Trail, I have been in a constant state of hunger.

Besides the number of miles I’ll cover in a given day and where I’ll sleep at night, I put the most thought toward what I’ll eat during the journey from Mexico to Canada. I constantly wonder if I’m getting the right nutrient balance and a sufficient number of calories, as any shortcomings in these areas could mean less energy, dramatic weight loss, or illness.

But finding the right mix of food to fuel hiking 30-mile days while still fitting it into a backpack is beyond difficult. Only now, with less than 600 miles remaining, have I figured out a good system. Although it might be almost too late for me to benefit fully from this knowledge, I’m here to pass along my lessons.

For me, the biggest challenge was finding the right ratio of calories to weight. It’s tough, because you move through areas with varying terrain and degrees of difficulty, and your gear and calorie expenditure differ pretty greatly from section to section. The average male needs 3,500 to 4,000 calories per day depending on the ruggedness of the path that day, while a woman needs to eat 3,000 to 3,500 given the same considerations. To cope, I tried everything from overloading my pack with more than a week’s worth of backpacker-friendly food to relying on luxurious items like cheese and salmon packets for just a five-day supply (which worked much better for me).

Here’s what I learned.

In the morning, I stick to three items: a Clif Builder’s Protein bar, a Kind bar, and beef jerky. (Courtesy Matt Vasilogambros)


Many thru-hikers swear by oatmeal, but I have found a simpler way to eat in the morning. As I break camp at 5:30 a.m., I chug water and eat a dense protein bar. I switch between Pro Bars and RX Bars. While pricey, they’re packed with fruit and nuts, have plenty of flavors to choose from to avoid flavor fatigue, and keep me full until the first water and snack break a couple hours later.

Why It Works: When Matt starts with a Pro Bar or RX Bar in the morning, he’s striking the right balance of carbs, fat, and protein to provide sustenance until his next snack break, says Brenda Braaten, a retired registered dietitian and thru-hiker.

Somehow, I weened myself off coffee and don’t need a caffeine hit in the morning. But Mio iced coffee squeeze is a good substitute when I decide I really need a fix.

As I travel before lunch, I use every stream or spring to fill up on water and eat more food. Between breakfast and lunch, I stick to three items: a Clif Builder’s Protein bar, a Kind bar, and beef jerky. Once the jerky runs out, which tends to happen in the first two days of my preferred five days’ worth of supplies, I lean on extra nuts packed for backup. I used to eat Welch’s Fruit Snacks, which are delicious, but I switched those out for a clementine at lunch. While it weighs more, there are few better pick-me-ups on the trail than fresh fruit.

Why It Works: Of all his snacks, Braaten likes Kind bars the best because they’re good sources of quickly digested glucose that your body burns as fuel. “Keep the sugar coming in a pretty steady stream all day long so you don’t deplete glycogen stores,” she says.

Tuna in a tortilla is the perfect hiker lunch. (Courtesy Matt Vasilogambros)


A staple of the hiker lunch is a flavored StarKist tuna packet on a Mission tortilla. Filling and protein-heavy, it’s also unbelievably easy to assemble. When we stay over in a town, I’ll pack out a block of cheddar cheese from the general store to add to the tuna. Cheese, while warm toward the end of the week, won’t spoil. In the bigger towns with better supermarkets, I’ll swap the tuna packets for an avocado or summer sausage. For more flavor and calories, I drizzle olive oil and hot sauce on the wrap.

After the tuna, there’s always a dessert wrap lathered up with Nutella or peanut butter and occasionally some dried banana chips. I’d caution against dehydrated peanut butter—it just doesn’t taste good.

To really make lunch filling, I typically supplement the wraps with a Snickers bar, a few handfuls of Goldfish or Cheez-Its, that clementine I mentioned, and a liter of water with four squirts of Mio electrolyte supplements.

Why It Works: These wraps provide fat, protein, and carbohydrates in one sitting, making them a great choice for trail lunches, says Braaten. The tortilla is especially key because it’s made of carbs that quickly convert to sugar to help fuel muscles. Since the body doesn’t have to reach deep into its glycogen stores for energy, the protein and fat aren’t used until later, providing greater sustenance and aiding muscle building, she says.

After a substantial lunch and with fewer miles to hike for the rest of the day, I only need two snacks to hold me over through the afternoon. I stick to another Kind bar and either a Nature Valley Sweet and Salty nut bar, a Bobo bar, or a pack of Keebler cheese crackers.

Why It Works: Planning for multiple snacks post-lunch is a good idea. “Small, frequent meals are much more efficiently digested than only two meals a day,” says Braaten.

Adding a salmon packet is a great way to get more protein. (Courtesy Matt Vasilogambros)


A Mountain House dinner is your tastiest bet, but it’s cost-prohibitive. A dinner pouch can run you upwards of $9. And though many hikers advocate for Knorr-brand sides and instant mashed potatoes, I quickly got sick of them.

Eventually, though, I found two meals that serve me well. The first, Near East couscous, is easy to make and filling and comes in many flavors, like broccoli and cheese, Mediterranean curry, and mushroom and herb.

The second came as a result of my rapid weight loss in the Sierra mountains: precooked quinoa, mushroom, and rice pouches sold in Safeway. Then I add a salmon packet for more protein. For flavor, I throw sun-dried tomatoes, olive oil, hot sauce, and taco seasoning into the pouch.

Why It Works: Timing of the meal is crucial. Hikers should eat dinner within 20 minutes of completing the day’s hiking to replenish their glycogen supply, says Braaten. While precooked meals make preparing dinner easier and quicker, be mindful that they’re generally higher in carbohydrates than protein. Braaten suggests supplementing these meals with a high-quality source of protein, like the salmon packet Matt uses.

I usually top the night off with a handful of peanut M&M’s, a half-liter of water with a Nuun hydration tablet, and a cup of green tea.

Why It Works: Staying hydrated on the trail is vital. While the amount of water a hiker should drink varies from person to person, Braaten says hikers can use how many bathroom breaks they take as a guide to whether they’re drinking enough water. Ideally, hikers should go to the bathroom immediately after waking up and take at least five breaks throughout the day. If they choose to have coffee or tea, both of which both contain caffeine and have a small dehydrating effect, hikers need to add an additional cup of water to their hydration plan to make up for water loss.

—Additional reporting by Colette Harris.

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Though building up your body and mind to tackle athletic challenges may seem like a unique endeavor, that’s not the case. Performance is performance, and there are many parallels between training for a marathon, making great art, and building a business that lasts. All are challenges that demand hard work and self-control in pursuit of a goal that is days, months, or even years away. Persistence is key, as is the ability to cultivate, sustain, and channel motivation.

Put simply, the overlap between professional, creative, and athletic success is huge. Here are a few timeless productivity lessons, or principles of performance, that apply no matter what you’re doing.

Prioritize Consistency Over Heroic Efforts

“People who don’t do creative work for a living often assume that it’s like what they see in the movies—that it’s 36 hours of muse-fueled blitz, sitting at a typewriter with a cigarette, pouring out genius,” says Ryan Holiday, creative strategist and author whose latest is Perennial Seller: The Art of Making and Marketing Work That Lasts. But that’s simply not the case. Though inspiration can suddenly strike, turning it into a tangible finished product is a matter of sustained effort, he says. “It’s getting up every day and doing the work…taking thousands of passes and polishes.”

The same holds true for athletic development, according to Steve Magness, professional running coach and my co-author of Peak Performance: Elevate Your Game, Avoid Burnout, and Thrive with the New Science of Success. “It’s okay to do what I call ‘see God’ workouts every once in a while,” he says, “but the best athletes are the best not because of a few massive efforts, but because of consistency over a long duration.” Look, for example, at this chart representing the training of one of Magness’ top athletes prior to a breakout competitive season. Five is an all-out, puking in the corner effort, and zero is a skipped workout.

Seek Mentorship

Having a mentor in entrepreneurial pursuits is “invaluable,” says Bob Kocher, a partner at Venrock, one of the largest venture capital firms in Silicon Valley. “Someone who cares about you, knows more than you, who will give you both good and constructive feedback and create opportunities is a blessing beyond imagination.” Additionally, a good mentor helps you avoid making the same mistakes they have. “We all need to grow, learn, and take risk,” says Kocher. “Having a mentor makes this massively easier.”

The value of a trusted coach is equally unquantifiable. A coach lets an athlete focus all their energy on execution, on showing up and getting the work done. Nic Lamb, who won the Titans of Mavericks in 2016, puts it like this: “Having trust in a coach is key. It removes the mental weight of needing to think about your workout. Instead, you can devote your full focus to showing up and executing.”


“When you’re working on a book, your brain is like a laptop that won’t go into sleep mode—it’s just getting hotter and hotter,” says Holiday. “Sleep is not just about rest. It’s the period where the mind is shut off and reset. You need that, or you will catch on fire.”

Kocher has observed that when entrepreneurs sacrifice sleep, they also “sacrifice creativity, self-control, and attention span.” Studies from researchers at Harvard demonstrate that our brains make sense of, consolidate, and store all the information we are exposed to during the day when we sleep. Additional research shows that sleep is integral to restoring willpower: When sleep is lacking, so is self-control.

Sleep, of course, also restores the body. It’s only after you’ve been sleeping for at least an hour that performance-enhancing anabolic hormones like testosterone and human growth hormone—both of which are critical to health and physical function—are released.

Put Yourself in Good Company

“I seek out people who know things I don’t and try to learn from them,” says Kocher, who adds that he surrounds himself with positive, smart, and diverse people who bring new perspectives and are not afraid to challenge him. Starting a business is hard, not only because you need to maintain motivation through ups and downs, but also because it can be easy to get stuck inside your own head. A supportive, honest, and open-minded peer group helps solve these problems, says Kocher, and encourages an entrepreneur to “pressure-test their thinking, assumptions, and ideas.”

Magness likes to say, “We is far more powerful than me.” A training group or team doesn’t just make you better because people are pushing you, he says, “but it also gives you a purpose beyond yourself.” A comprehensive analysis published in the journal Medicine and Science in Sports and Exercise found that one of the most powerful motivators to stick with a fitness program is being in a supportive environment.

Focus on What You Can Control, and Don’t Ever Become Complacent

“All work leaves your hands at some point,” says Holiday. And what happens next is almost always out of your control. “People either like your work of art or they don’t. The ball goes in or it doesn’t. Your time was good enough or it wasn’t.” Worrying about the result is a distraction from what you really should be thinking about: how you can respond, and what happens next. According to Holiday, this premise is just as true for a successful result as it is for a failure.

“I think people believe arriving is the big win. Don’t get me wrong—it’s an honor to make the NFL, or to be a published author, or to be invited to represent your country at the Olympics. But to me, that’s only the beginning. I want to beat myself each time,” says Holiday. “A lot of what goes into creating a body of creative work is the same thing that goes into being a great athlete: preparing, learning, not being complacent, finding ways to challenge yourself, and staying healthy. Look at Tom Brady: He looks better right now than he does on his 2000 draft-pick card. He’s smarter, wiser, and more dedicated. That’s the model to look at, I think.”

Brad Stulberg (@Bstulberg) writes Outside’s Science of Performance column and is author of the new book Peak Performance: Elevate Your Game, Avoid Burnout, and Thrive with the New Science of Success.

If you’re looking to make a dramatic shift in terms of how you feel and look, one of the best ways to do that is via diet shakes. People love diet shakes because of the ease of application, and they are also an incredibly easy way to track calories. When it comes to losing weight, you’ll want to always count calories because it’s undoubtedly the most effective strategy in terms of achieving what you would most want to get out of your dieting endeavors. 

Well, rather than sitting on the sidelines, you can immediately make a major impact and get into the dieting swing of things by doing this through diet shakes, where you’ll immediately notice a difference. This is dramatically important because if you don’t take the time to keep all of this in mind, you’re not going to reach your goals.  

One of the most popular diet shakes on the market is ultra-popular Medifast diet shakes which are sold in most commercial stores. However, there is a rising challenger in the league of diet shakes, and it’s called the 310 shake by 310 Nutrition. Not only is the latter an amazing product, but it comes with an entire community in tow. Can Medifast stack up? Let’s find out.  

Medifast Diet Shakes 

When it comes to the diet shakes by Medifast, there is no doubt that they are very popular. These shakes not only provide people with precisely what they need in terms of great products, but they also address all of the nutritional concerns that a lot of other people suffer from.  

This is why you need to keep everything in check because if you don’t, you’re going to notice rather quickly that these are shakes that contain some qualities that you might not particularly like. You need to be aware that with the Medifast shakes, they do provide a nice solid amount of lean protein sources, but keep in mind, they’re all animal and GMO-sourced.  

Now, some people might not care about that, but if you’re looking to be healthy and not just lose weight, this is something that should be of a major concern to you. A lot of those artificial ingredients and hormones can have extra side effects that people tend to ignore. Rather than conveniently putting those side effects on the sidelines, you’ll want to be hyper-aware of what these shakes may leave you with. And there may actually be a better method of getting the protein you might need through better options on the market. 

The 310 Diet Shake 

Yes, 310 Nutrition might be a name you’re unfamiliar with, but not for long. They’re quickly taking the market by storm, and one of their best products is the 310 Shake. This is an amazingly unique diet shake not only because of the top-notch flavor, which is undoubtedly the best in the entire diet shakes market, and no, that’s not hyperbole.  

These shakes are tremendously beneficial in terms of what they offer as ingredients. You’re getting amazing levels of protein, fiber and other add-ons that you otherwise wouldn’t find. This also ensures that these are products that can provide you with everything else you might want and more, solidifying them as solid shakes with unbeatable matchups. When you combine everything in the convenient package you get with the 310 Shake, you’re getting something that is not only phenomenal from a product perspective, but you’re also getting something that can really change how you approach and look into improving your goals. 

Many of the shakes feature only natural, plant-based proteins that don’t contain controversial or unnatural sources. This means you’re getting exactly what you’re looking for without any catches. This is an amazing shake, and if you’re not satisfied, then maybe you’ll need to get your taste buds checked. Aside from just being a protein-based product, you’re also getting a lot of essential greens. These do wonders for improving your health; in the long run, they’re going to be invaluable if you do decide to stick with something that is going to fill in all of the nutritional gaps that you’ll need for long term sustenance and nutritional success.  


To really understand why the Apple Watch Series 3 matters, you have to recall a bit of recent tech history: the announcement of the first Apple Watch in 2014 was a very big deal. For the first time, a leading technology company was plunging headfirst into the smartwatch space. While reviews of the Watch were mixed, consumers were enthralled. And the product sold well. Because the Watch had fitness-tracking capabilities, many analysts predicted that it would mark the the end of brands like Garmin and Fitbit. 

Instead, the opposite happened: the Apple Watch made entire wearables market better. Sales of smartwatches and trackers surged. Garmin introduced the Forerunner 225. Fitbit launched the Blaze. Meanwhile, software developers like Strava made wearable-friendly apps.

A similar scenario played out in 2016, with the release of the Watch Series 2. Apple added health and fitness capabilities, but once again the competition responded with their own upgrades, most notably improving build quality, continuing to roll out optical heart rate monitoring, and adding smartwatch features. 

After a week of testing the $399 Watch 3 on an abbreviated fitness circuit—bike rides, long walks, navigating cities—I can safely say that Apple will once again have an outsized impact on the smartwatch industry. The Series 3 isn’t perfect, but at least in the short-term, it’s going to make every other smartwatch on the market feel obsolete. 

What Is This Thing, Anyway?

In our preview of the Series 3, we declared it a watch that athletes will want. This earned us scorn from some Facebook readers who were underwhelmed by the Watch’s battery life and insisted that it should not be categorized as a high-performance fitness tracker. 

They’re right. But Apple has never presented the Watch as the most sophisticated fitness tracker on the market. The first version was a smartwatch with some solid fitness-tracking features. In version two, it became a bona fide fitness tracker with strong smartwatch capabilities. Version three is a stellar fitness tool, and hands down the best smartwatch available for iPhone owners. 

By design, the Watch is not supposed to be the perfect gift for your Ironman-obsessed sister-in-law. There are some great high-end, sport-specific products that already do things like sync with SRM power meters. Instead, it’s meant for the much larger number of us who want a device to track our hikes and rides but that can handle smartwatch functions like streaming music and responding to texts. This review is written with those readers in mind. If, like some of my Outside colleagues, you demand a tracker that holds a charge for five days and has tactile buttons for workouts, feel free to stop reading here.  

The New Hardware

The Series 3 looks and feels just like any other Apple Watch, and it’s compatible with all your old bands. Complete details are on Apple’s website. And you’ll find them thoughtfully dissected and explained on sites like The Verge. For our purposes, there are two main considerations: 

Cellular connectivity. That’s the big headline. You can now (actually, coming next month), stream music from your Watch, make calls (directly on the Watch or by using Apple’s AirPod earbuds), receive texts, and let friends and family track your location without your iPhone. This all happens seamlessly from your current phone number. And it works better than advertised: the calls are crisp and the Watch is responsive. I expected that I’d find myself missing my phone. I rarely did.

(Note: Other reviewers experienced significant issues with the Watch’s cellular connectivity. In our experience, a few texts did fail to send on the Metro and Siri wasn’t talking back. But calling worked just fine in D.C. and Santa Fe.)

Beyond the cellular upgrade, there’s the addition of a barometric altimeter. This tool helps the watch accurately measure elevation gain. There isn’t much else to say beyond: it works, and that’s something that will make athletes happy. You can now ride and run without your phone and get accurate climbing data.

What about GPS and the heart rate monitor? Given the well-established credentials and limitations of the Watch plus its performance throughout the test, we won’t be touching on those previously reviewed feature. We will however briefly praise the new Sport Loop. It’s comfortable, looks fun, and it allows you to wear the Watch more tightly around the wrist. That snug fit helps the optical heart rate sensor perform at its best.

The New Software


The biggest fitness upgrades come courtesy of watchOS4, the new operating system available to all Watch owners. This is a radically simplified interface that puts your health at the center of the experience. Practically speaking, it means you get a refreshed Workout app, plus some exciting new heart-rate monitoring features:

  • Heart-rate variability tracking. This stat can be used to understand how well you’re recovering and if you’re about to get sick. The Watch measures this when you initiate the Breathe app (Apple’s mindfulness tool) and during other times the Watch detects to be suitable throughout the day.
  • Resting heart rate: The beats per minute of your heart at rest, a measure of overall fitness and fatigue.
  • Walking average: A new tool from Apple that measures your average heart rate while walking.
  • Heart rate recovery: How your heart rate responds after a workout, another potential measure of fitness and fatigue.
  • Elevated heart rate: An opt-in system designed to notify you if their your rate goes above a self-selected threshold when you’ve been inactive for ten minutes or longer

The above upgrades are significant enough to warrant a software update.

How Does It Work?

For this review, I went on a handful rides and spent several days trekking around Washington, D.C. on a trip. I didn’t get a chance to test the Watch in the pool or on a trail. For our long-term test, we’ll be putting the Watch through a more thorough battery of workouts. 

(Scott Rosenfield)

Exercising with the Watch 

I got the watch at about 4:45 p.m. on Tuesday, September 12. I jumped in a car with Outside executive editor Michael Roberts at about 6 p.m. While he drove away from the Apple Park to escape traffic, I set up the Watch, gossiped about coworkers, and ate an energy bar. By 7:30 p.m., I was ready to ride. And while my original Watch died partway through the excursion, the Series 3 kept its charge.

During our hour-long ride, I simultaneously tracked my activity through the Workout app and on a secondary phone (that wasn’t paired with the new Watch) using Strava. I didn’t listen to music or text my friends while riding, but the Watch’s new hardware was a difference maker. It made me feel that I would have been comfortable exploring without a phone. And it allowed me to track an elevation gain of 1,200 feet. These seem like small things, but a product like this is about small advances and upgrades.

On my second ride, back in Santa Fe, the Watch showed an incorrect elevation gain recording, likely the result of a thunderstorm that blew in while I was out. The drastic change in air pressure would have have affected any barometric altimeter. As expected, it was an issue I didn’t experience on any other rides or walks.

(Scott Rosenfield)

Choosing between using Strava and Workout is a common Watch experience, and one that predates the Series 3. You need to think about how you’re tracking your workouts and storing your data or you’ll end up with a confusing training log. There are also real tradeoffs to be made depending on what app you use.

Let’s start with the Apple ecosystem. For those new to Watch, it works something like this: on the Watch you record your workouts in Workout and track your overall activity (hours of the day with standing, overall movement, and minutes spent exercising) in Activity; on the phone, all your data is presented in Health with workouts specifically appearing in Activity. That makes Health your default training log. If you’re new to training or activity tracking—or if you’re comfortable storing everything in Health—this isn’t an issue. Your data is all in one place. 

For people with years of data stored in apps like Training Peaks, or for folks who want a robust desktop interface for reviewing their stats, it’s a bit problematic. Apple doesn’t have a web app or any desktop interface for viewing Health data (and because of the company’s privacy stance, there likely isn’t one on the horizon). And while exporting your data is doable, it isn’t convenient—a sizable drawback for a device designed to make health and wellness easy. Practically speaking, it means that if you want to record everything through Workout—because you prefer the interface or just like keeping everything within Apple—and then have that data automatically export and sync to, say, Strava, you’re out of luck. How big of a deal is this? For Outside readers, it hasn’t been a frequently voiced concern. And for me, it just means that I should eventually pick one primary platform. 

Overall, the Watch—from a sensor and software perspective—accomplishes what I currently need from a fitness tracker on the bike. It shows me distance and duration in real time. And if I’m using Strava, it uploads my ride when I’m done. It has replaced my Garmin computer in almost every situation (save for ultra-endurance death rides). But the Watch form factor is not the ideal tool for cyclists. To view any of the stats, I have to raise my wrist from the handlebars. And to adjust music or fiddle with settings, I have to take both hands off the bars. To be clear, these are criticisms of all watches. But they’re more pronounced with the Watch. Some watches have an always-on screen that make the glancing easier. And other brands come with handlebar attachments. Runners I’ve spoken with have expressed skepticism about the lack of buttons and the screen’s ability to respond in rain and through sweat. This is a valid concern, but one I haven’t really noticed on the bike (except while wearing long-finger gloves). The touchscreen always—even in light rain—has worked fine for me. I’ve also found it to be visible under bright sunlight.

(As someone who once fancied himself a decent cyclist, the most Watch-specific issue is that it doesn’t currently sync with ANT+ devices, such as power meters. That pertains to a small subset of cyclists, but if you don’t leave home without your power meter, the Watch will not be your all-in-one fitness tracker.)

Texting and Calling on the Watch

I underestimated just how impactful the Watch’s cellular connectivity would be. On short rides, it gives me the comfort to go without my phone. If something were to happen, I’m confident that I could call for help. When paired with the AirPods, the call quality was clear. Likewise, being able to quickly send a text was a surprisingly important feature. Running late? Instead of leaving someone on the other end worrying, I could quickly shoot a message. While I didn’t test the GPS mapping functionality on the bike, I did use it to get home from a concert after my phone died. And I could see it helping me navigate a new city while on a run or ride. 

Music on the Watch

There are legitimate reasons to stay within Apple’s ecosystem. On the Watch, their apps tend to just work a little bit better, at least right now. The biggest example of this for me is the integration of Music and Workout. When I ride on quiet roads, I like to keep one earbud in to listen to music and the other dangling so that I can better hear approaching cars. My AirPods plus Watch have replaced a full suite of devices I used to ride with: a phone for connectivity, wired headphones, and a Watch for fitness tracking. In Workout, it’s simple to change the song or volume: just swipe and then use the controls as usual. You stay within Workout the entire time. It’s not so easy in Strava. You have to exit out of the app, open Music, make the change, and move back in. Again, it’s a seemingly minor complaint. But when you’re in the middle of a run or ride, those inconveniences matter—both in terms of pacing and also keeping your attention on traffic. Again, pay attention to the apps you use and how you like to use them. Spotify offers an app for AndroidWear but doesn’t have one yet for the Watch (though there is one coming).

Testing the Battery

Everyone wants to know about battery life. The problem with measuring battery life is that usage can vary dramatically between people. To provide the most accurate possible assessment, I conducted a variety of tests: 

  • Go-till-you-die with heavy use: Almost 16 hours. I started using a fully-charged Watch at 7 a.m. I used it all day while traveling to respond to Slacks and texts. I turned it off at night for about eight hours. I turned it on the following morning and it made it until about 11:00 a.m.
  • Go-till-you-die with Workout: About three hours. This was the most surprising result of the test. I started a walking Workout, used the Watch to text and navigate, and played music. It didn’t last long. To confirm the result, I tested it again but spent less time playing with apps on the Watch. In that case, I got over four hours of Workout tracking—in the context of a full day of use while traveling—before getting the 10 percent battery remaining warning.
  • Workout Power Saving Mode: Full day. I launched this mode, which disables the cellular connectivity and optical heart rate monitor (but maintains GPS functionality), and initiated a walking Workout. I kept the session going for about five hours. Then I turned off power-saving mode and went about the rest of my day without running out of charge. 

If you’ve owned a Watch previously, there isn’t much new here. Using more features drains the battery more quickly. Expect this Watch to last about as long as the old one, so long as you’re not constantly calling or texting people. If you’re new to the Watch, though, some explanation: for most workouts longer than two hours, I use an external heart-rate monitor and disable the optical HRM. That helps preserve battery. 

What do I make of the above? For 95 percent of my use cases, the Watch will have enough battery to make me a happy user. Long rides? Check. Long hikes? Check. Ironman triathletes won’t be in luck, but they may want another device specifically tailored to triathlons anyway. 

In-house, we’ve devised a holy grail test for fitness trackers: riding to a campsite, camping out, going for a short hike, and then riding back home. The Watch should theoretically be able to hold a charge for that (something I’ll confirm in the long-term review). More than any other aspect of the Watch, this is one that I am eager to continue testing.

Activity and Workout 

(Scott Rosenfield)

If you already own an Apple Watch, the new software will dramatically transform your device. The changes to Workout and Activity are subtle, but they reveal so much about Apple’s understanding of health and wellness.

When I interviewed Jay Blahnik, Apple’s director of fitness for health technologies, in 2015, he synthesized Apple’s wellness stance as follows: there are three key trackable elements to activity, including standing, all-day movement, and exercise. The Watch is designed to measure all three—and to nudge you into making smarter choices. To track each element, the Activity app features three rings, one for each of the above elements. Your daily goal is to close all three rings. 

In recent years, Apple has added sleep, nutrition, and mindfulness to their health mix. While the Watch now has a built-in Breathe app to encourage mindfulness, sleep and nutrition are notoriously difficult to track and absent from the Apple native app ecosystem (save for third-party apps). Many studies and anecdotes have shown sleep tracking to be, in short, a sham. And calorie counting requires user active user participation: you have to actually input what you’re eating. 

This understanding of health is surprisingly hack-free and accurate. That’s where the latest version of watchOS comes in. The device is slowly but steadily gaining the ability to influence behavior. Until now, Apple largely accomplished this through the ring interface. But with smarter Activity coaching, Apple is taking a big step forward. In the morning, the Watch will prompt you to stay more active by identifying a streak you’re on and urging you to keep it up. If it can’t find something forward-looking, the app will pick out one good thing you did the day before and urge you to do it again. The smarter coaching shows itself in two other situations. If you’ve closed your ring on a run, the app will give you an in-the-moment notification. This brings the reward a lot closer to the action. And, perhaps most importantly, if you’re not on track to close your rings, the app will prompt you to get up and go walk at a brisk pace. It’ll also tell you the exact amount of time you need to move to hit your goal. Apple picked walking because it’s something almost anyone can do in almost any situation. (It sends the notification early enough in the day that you can take action. There’s another notification if you’re a hair away from hitting your goals.) 

I admit that the above doesn’t sound particularly impactful. Will a notification actually make anyone healthier? In my experience, the answer is yes. While I know some Watch owners who never took to the rings and don’t find them motivating, I’ve had the opposite experience. The Watch helped me become the healthiest version of myself, in a time period when it was most difficult to stay fit. And on the flip side, when a broken band kept my Watch out of commission for over a month, I found myself gaining weight, moving less, and ignoring my body. Coupled with the experiences of so many others, I firmly believe that the Watch can have a significant impact—if your personality is primed to respond to its prompts. For this population, I think the new notifications will be a significant step forward. They’re gentle enough to not be annoying, but also actionable enough to change the trajectory of a day. Their impact is something I plan to track carefully over the next few months of long-term testing.

It bears mentioning that while Activity is the epicenter of change in watchOS4, the Workout app is also much improved. You can move from workout to workout seamlessly (say, if you’re transitioning from running to biking). And the app itself is just much cleaner and easier to use. 

Heart Rate Monitoring


It’s too early to say how helpful and influential Apple’s foray into sophisticated heart-rate monitoring will be. But I get the sense that it’s about to turn a large subset of Watch users into biohackers.

Historically, the Watch did essentially one user-facing thing with heart rate: it provided an average following workouts. That was it, and it was a lot less sophisticated an output than what most other apps and watches provided. With watchOS4, Apple has opened up so much more data. For the purposes of this review, I’ll segment it into two buckets: performance and health data. 

Let’s start with performance. Measures like heart-rate variability, resting heart rate, and recovery heart rate have long been used by athletes across an entire spectrum of sports. When in serious training, I’ve found recovery heart rate and resting heart rate to be surprisingly effective tools. In combination, the two measures have predicted common colds and helped me tailor my training load (in conjunction with measuring training stress score through Training Peaks). I’ve also found the measurements to be helpful for athletes I’ve coached, particularly in convincing them to listen to their bodies (people tend to trust a heart-based number more than perceived exertion). While I never before had access to Apple’s walking heart rate average, I did have my own version of it. I’d start each indoor workout with a 10 minute interval at 200 watts, or a brisk pace. Tracking my average heart rate during this interval and then measuring the recovery period afterward was the single most effective metric I had in training. And it’s something that Apple is trying to replicate with walking heart rate. 

When it comes to evaluating these metrics, it’s worth keeping a few things in mind: there isn’t consensus on their use, but plenty of people find them helpful. That may be why Apple has chosen to steer clear of providing actionable insights from the stats. If your resting heart rate has risen for a week and your heart rate isn’t recovering like it used to, the Watch won’t tell you to take a preemptive sick day. But there’s nothing stopping an app-maker from using that data to provide such insights. While I’ve criticized fitness-trackers for the lack of useful recommendations in the past (possibly due to FDA restrictions), I think Apple made the right move. This type of biometric data is too likely too personal to provide population-level takeaways from. I’d prefer for a third-party app that specializes in this type of analysis take the lead. This is better for the Watch’s credibility and for users.

Given the above, the following may come as a bit of a surprise: I’m very excited to see where Apple goes with its Heart Study and the elevated heart rate notification system. The former is a study designed to help spot things like irregular heart rhythms. The latter is something you can start using now. If you opt into the monitoring, Apple will notify you if your heart rate goes above a set threshold of 100 to 150 beats per minute during a period in which you’ve been inactive for 10 or more minutes. This is designed to help you flag potential health issues like panic attacks and tachycardia. In a team meeting post-keynote, a handful of Outside editors debated the merits of such a system. Would it create a wave of false positives leading to needless and expensive testing? Would people simply ignore it? 

The exercise and health sources I reached out to about the technology were cautiously optimistic about the functionality, but were hesitant to go on record without using the device or speaking with Apple. In my experience with the Watch, I had one notification. After looking at the surrounding data, I concluded that it was an odd mix up versus something to call my doctor about. Given that the warning is opt-in and relatively muted, it’s hard to imagine the technology leading to a series of false positives and needless interventions.

The Watch as Your Phone

Will the Watch allow you to go all day without your phone? If you use your iPhone largely as a phone, the Watch is a perfectly good all-day replacement; if you use your iPhone as a smartphone, you will want to use something more powerful than the Watch at some point during the day. Essentially, the Watch does things like responding to quick texts, placing calls, and surfacing urgent email really well. In many ways, it works better than the phone. Many users set up the Watch to screen out all but the most crucial notifications. This brings the important into greater relief. Because the only folks who can reach me on my watch are immediate family and my boss (and his boss), I jump when it buzzes. Since anyone can reach me on my phone, I don’t pay as much attention to the notifications. But for most everything else, the phone is unsurprisingly a better device. 

The Bottom Line

When the Series 3 was announced, we put together a brief post with our initial thoughts. Essentially, we tried to locate the product’s audience by saying: it’s good for the health and wellness set, really good for the fitness set, and OK for the hard-core athlete set. We stand by that overview. This Watch is a device that most readers could benefit from. If you’re still using an original Watch or are looking to buy your first wearable, the Series 3 is the tool Apple always wanted to build: a fitness tool with smartphone capabilities too useful to take off.