Alex Hutchinson
@sweatscience
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Outside columnist, author of THE EXPLORER'S GENE (coming March 2025 from @marinerbooks) and ENDURE, Globe & Mail, ex-physicist, not-quite-sub-4 miler.
Toronto, Canada
Joined March 2009
Big day! Got the early galleys for my new book, which comes out on March 25, 2025. It's called The Explorer's Gene: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map. Find out more and (please!) pre-order here:
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It's been 9 years since I started telling interviewees that I was working on a book about the limits of endurance. Now it's just 10 days until that book goes on sale. Thanks to everyone who read, discussed, and debated these topics with me over the years!
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Pretty cool "naturally randomized" experiment: the right to buy a car in Beijing is determined by lottery. Win that lottery, and 5 years later you'll be ~22 lbs heavier if you're over 50.
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Our blueberry bush produced its first ever berry. All four of us enjoyed our portion.
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70% of elite marathoners land on their heels; Almaz Ayana's stride length is asymmetric by 20cm; and you should throw a hammer at 45 degrees: insights from a massive IAAF biomechanics study.
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Neat study suggests there's a trade-off at the mitochondrial level between aerobic power (VO2max) and efficiency: maximizing one may hurt the other. Result: a new threshold ("complex I max"), and an explanation for Oskar Svendsen's mediocre efficiency.
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Kipchoge's incredible world record, solo for a huge portion of it, felt almost like the antithesis of the Breaking2 extravaganza. But I don't think 2:01:39 would have happened without that prior 2:00:25. #BerlinMarathon.
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After 4 days of sitting (<4,000 steps/day), you become "exercise resistant" and don't get some of the usual acute metabolic benefits (blood sugar, insulin, triglycerides) from a 60min workout. Potential interaction between sitting time & exercise habits:.
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Which is more important for building endurance (via mitochondrial adaptations): training volume (i.e. running more) or intensity (running faster)? An interesting "CrossTalk" debate in the Journal of Physiology lays out the case for each view:
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"89% of international U17/U18 athletes never reach that level as seniors, and 83% of international-class seniors weren't U17/U18 internationals". A good reminder that athletes whose talent seemingly emerges in their 20s are the rule, not the exception.
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Man, Eliud always makes me smile. All that running business aside, what a great guy.
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The Journal of Physiology recently published a review titled "The Anaerobic Threshold: 50+ Years of Controversy." Here's my attempt to make sense of its account of one of the most confusing and misunderstood concepts in endurance training and physiology.
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With every step Kipchoge now takes, it's the fastest a human has ever run for this distance. #breaking2.
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Finally, a mandate we can all agree with: forcing exercise physiology students to buy copies of Endure. Awesome to see the University of Calgary leading the way! ;)
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Quick summary of my reaction to Eliud Kipchoge's 2:01:39 marathon world record: . [long silence. mouth hanging open but not making any sounds. more silence]. Here's the extended version of my reaction:.
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Researchers used 3D gait analysis and machine learning to sort a bunch of runners into 5 groups with similar strides. Then they checked for similarities in the types of injuries they developed, and to their surprise found. nuthin'.
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Pretty neat study: make people think they're hot (with a small electric heat pad on their back), and they'll slow down even though body temp, sweat rate, heart function etc. stay the same. Perception matters.
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If, like me, you really only want to do one set per exercise of your strength routine, here's some research to reassure you you're not wasting your time. Also, some recent findings on "muscle confusion" and the difference between light and heavy weights.
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If you read one article this year about what Michel Foucault's analysis of discipline can teach us about the inherent limitations of our usual approach to pushing the limits of endurance, please make it this one:.
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Alternating 30s hard and 15s easy produced bigger gains than a more typical session of 5min reps, seemingly by increasing lactate tolerance, in elite cyclists.Not to oversell it, but it seems like a somewhat uncommon workout style, perhaps worth a try.
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New study finds that when you think about your running form, you get 2.6% less efficient than when you just watch the scenery; when you focus on your breathing, you get 4.2% less efficient. But there are some caveats worth considering.
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“Revised *and* updated, you say? And with a new afterword and an elegant softcover binding that absorbs spills and repels rain? How could it be possibly be available for preorder for just $12.79, shipping Feb. 16?!”.
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People with higher emotional intelligence run faster half-marathons, according to Italian researchers. This may seem odd, but pushing your limits in a prolonged endurance task requires managing negative emotions. Next step in this research: improving EQ.
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I take no joy in sharing this, but it's an ESSENTIAL read for anyone involved in sport. Megan Brown's story is not unique. Fantastic reporting by @mdfdoyle for @globeandmail.
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No, running won't ruin your knees. But nearly half of U.S. adults end up with knee osteoarthritis anyway, so *something* is ruining knees! I asked a bunch of experts what we can do to preserve and protect our knees before they start failing.
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I recently spent a couple of months wearing a continuous glucose monitor, exploring the idea that monitoring your blood sugar levels is like a "real-time fuel gauge for endurance athletes." Here's my deep dive into the science behind this claim:.
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“Teleoanticipation” is basically the science of finish lines, and how their presence (or absence) influences us. In light of recent vaccine news, I wrote about what sports scientists who study this topic might have to teach us about the coming months.
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My take on a big new meta-analysis on ice baths, massage, compression, etc.: "If you have a recovery routine that helps you feel better sooner. maybe the best advice I can offer is the old saying: Ask me no questions, and I’ll tell you no lies."
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"Take a moment to let that sink in: how much and how vigorously you move are more important than how old you are as a predictor of the years you’ve got left.". This was a neat (and surprising) study.
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Most supplements, in my view, are useless. That's not a controversial take. But I argue here that the *pursuit* of supplements and other hacks directly undermines our quest for better performance and health in several ways. Everything has a cost. ⬇️.
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People often claim that "lack of time" is a reason they don't exercise. With Martin Gibala's latest study (sprinting up the stairs for 20s a few times a day makes you fitter), it's a good time to ask whether time is really the issue.
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Heat training boosts plasma volume. It's not clear whether that's directly useful in non-heat conditions. But a new study suggests that if you sustain it for 5 weeks, the extra plasma dilutes your blood enough to stimulate EPO and new red blood cells.
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CORRECTED! New abstract finds that athletes consistently go HARDER than coaches ask on EASY days, but EASIER on HARD days: "Most of us, Foster believes, have internalized some vestigial remnant of the puritan work ethic, conflating hard work with virtue."
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Two workouts might produce similar external results (VO2max, time trial) through different internal adaptations. Some interesting new evidence suggests longer intervals/runs target the heart (O2 delivery) while shorter ones target the muscles (O2 uptake).
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A Heartbreaking Tale of Staggering VO2max: details of prematurely retired cyclist Oskar Svendsen's 96.7 ml/kg/min reading in a newly published case report. Almost as impressive: his 77.0 after 15 months without training.
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We know exercise reduces cancer risk. But why? A new opinion piece proposes that "energetic capacity" (i.e. high VO2max and resting metabolism) helps sustain a prolonged and robust immune response. Upshot: fitness matters more than training volume.
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Plyometrics are as effective as supershoes for boosting running economy. But they're seen as complicated, time-consuming, and possibly injury-inducing. -> new study finds that simply hopping on the spot is enough to trigger significant economy gains.
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Neat insights from analyzing Strava data from 300,000 marathoners: if you miss a week of training during your marathon build-up, expect to run ~4% slower than you would have. Note that this number can't be used to claim adjusted PBs or qualifying times.
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For the same reasons I enjoy racing long distances and sticking my finger in electrical sockets, I decided to write about the latest LCHF data: @LouiseMBurke's attempt to replicate her prior findings about reduced efficiency and race performance.
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Periodic smiling, a la @eliudkipchoge, improves your running economy, according to new research from @noelbrickie:
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Very cool stuff: detailed lab and track testing data from the 16 finalists in Nike's Breaking2 selection process. Biggest surprise to me: average VO2max was "only" 71.0 ml/kg/min, and only one runner above 77 (I have my suspicions about who that was!).
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A new computational fluid dynamics study suggests you should be >4m behind other walkers, >10m behind runners, >20m behind cyclists to avoid droplets. That's if you're directly behind - much better if you're off to the side. Note: not yet peer-reviewed.
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What does it take for a 59yo to run a 2:27 marathon? The ability to sustain 91% of VO2max for 26.2 miles, according to a recent @japplphysiol paper. Similar to 70yo Gene Dykes sustaining ~95%. Neat insights into VO2max and aging. (Yes, both wore Vaporfly.)
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An emerging new theory about the "interference effect" between strength and endurance training suggests some practical ways endurance athletes can build muscle despite their mileage. Interesting insights from @musclescience:
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The physiology of my favorite workout, descending ladders:. Running above critical speed depletes your aerobic capacity. The more depleted it gets, the faster it recovers during breaks. Thus, progressively shorter intervals maximize your time near VO2max.
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A 53yo triathlete took 12 weeks off training and his VO2max dropped 10%, the equivalent of 15 years of aging. Then he resumed training, and 12 weeks later his VO2max was 5% *higher* than baseline. A neat case study with interesting muscle biopsy data:.
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Why do athletes nap so much? New research suggests it's not because they're more exhausted or sleep-starved than the rest of us. Instead, they're "appetitive" rather than "restorative" nappers and have high "sleepability" (i.e. are good at falling asleep).
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For my final RW column, an attempt to sum up the big lessons learned in 5 yrs of exploring the science of endurance:
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The neurophysiology of how mental fatigue affects physical endurance. It's all about adenosine accumulation in the brain, according one hypothesis. The new goal: figure out how to lower adenosine levels.
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Really interesting paper from @ArturoCasadoAld et al. lays out the science of the "Norwegian method" of lactate-guided double threshold days, as used by Jakob Ingebrigsten and many others these days.
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New twist on old breakfast debate for endurance athletes: Even if you get enough calories over the course of a given day, spending too many *hours* in significant caloric deficit is associated with higher cortisol and lower testosterone/estradiol levels:.
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Some interesting data on how pregnancy affected the career trajectories of marathoners in the top 150 all-time. Spoiler: 23 of 37 mothers on the list ran their best times (avg 2:21) after their first kid was born.
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Forget ice baths, elite athletes are all about heat these days. Here's a look at some of the ways they're deploying heat as a performance enhancer, altitude alternative, health booster, etc.:
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The new shoe rules aren't the end of the Vaporfly story, but they are the end of a chapter. To figure out what comes next, it's worth looking back at how we got to this point, and how things might have been different (or not). Here's my take on that:
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What's your "speed reserve"? Divide your max all-out sprint speed by your max aerobic speed, and you get a ratio that offers some interesting insights into your profile as an endurance athlete--and perhaps a reminder that you've been neglecting true speed.
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Don't forget to exercise: 12 weeks of interval training boosted performance on a memory test by 30% in older adults.
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New beet juice study on well-trained (VO2max > 60) athletes find a benefit with relatively high dose (2 shots a day for 4-7 days), despite earlier results suggesting it may not work for very fit athletes. Similar results at sea level and 2500m.
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Neat study: take a bunch of runners, ramp up their mileage by 30% over 3 weeks. Half end up "overreached" - and those runners, on average, have a higher proportion of fast-twitch muscle fibers. Hints "FT" and "ST" runners respond to different training.
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"Polarized training is/is not optimal for endurance athletes.". That's the proposition in a new Medicine & Science in Sports & Exercise debate, with big names on both sides. Here's my take on their respective arguments:.
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The case for ankle strengthening to prevent a decline in running efficiency as you fatigue:
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This year marks the 100th anniversary of Hill & Lupton's original paper "discovering" VO2max. To celebrate, here's a guide to VO2max: what causes it, how to measure it, how to change it, and why it's significant for both fitness and health. ⬇️.
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This is a really interesting graph - not just the 800, but the monotonic trends on either side. It's like there's something that has improved "pure endurance," and something else that has improved "pure speed," but their effects somehow diminish when you mix them. Very curious.
% improvement in men's WR running speeds pre-first IAAF WC(1983) to present. 800m 'underperforms'?
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If you can do 40 push-ups in 2 minutes (and you're a middle-aged male firefighter), you'll live forever. Okay, not quite. But some interesting data on the prognostic value of push-ups (and other functional tests) for cardiovascular "events":
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The Canadian marathon record holder, @MalindiElmore, just signed a new shoe deal. In the Vaporfly era, that's a high-stakes decision--so she headed to the lab with a few pairs of shoes to do personal running economy tests. The results were surprising.
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That was a hell of a weekend. After letting it sink in for a day, here are my thoughts on what Kipchoge's and Kosgei's runs mean. Teaser: I'm definitely feeling a case of the shoe fatigue that's going around.
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New study: the thick foam midsole in Nike's Vaporfly 4% shoe stores and returns ~45 times more energy per stride than the bending of the carbon fiber plate. The plate acts more as a lever than a spring, changing ankle torque, but that's a smaller effect.
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Cyclists at UCI road world champs in Qatar swallowed thermometer pills before racing. Highest core temps (up to 41.5 C / 106.7 F) were in the ~45min time trial, not the ~3hr road race. Body heat is about intensity more than duration or dehydration.
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For the past few years, a surprising number of world-beating endurance athletes have been slurping down a mysterious soup before their races. Maurten, whose hydrogel upended the sports drink world, believes it's about to do the same with. baking soda.
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There's been lots of chatter about baking soda as the hottest supplement of this summer's Olympics. Now there's also a peer-reviewed study supporting the claim that Maurten's new version works - and not just for short mid-distance events:.
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Data from 120,000 runners shows that slow and fast marathoners do essentially the same amount of medium and hard training, but vastly different amounts of easy training. But does that really mean that slow marathoners would get faster by training easier?.
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Review in @SportsMedicineJ estimates the least strength training you can get away with and still get fitter: 1 workout/wk, 1 set/muscle group, 6-15 reps, 30-80% max. Doesn't sound like much. but is more better for long-term health?. Details:⬇️.
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Evidence keeps failing to back up the electrolyte/dehydration theory of muscle cramps. But the new theories don't tell us how to avoid them. Here's some new data that (again) implicates muscle damage, and suggests strength training as a countermeasure.
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Athletes with poor or moderate self-regulatory skills (planning, self-monitoring, evaluation, reflection), as assessed by a psych questionnaire, were 4.6 times more likely to miss training with an overuse injury:
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I can't deny I've felt a little Eliud Kipchoge fatigue lately: after all these years of unbroken success, what else is there to say about him?. Answer: this piece by @Cathal_Dennehy. Some really telling anecdotes and beautiful writing. 100% worth a read.
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You periodize your training (whether you're aware of it or not!). A big new paper argues that you should also deliberately periodize recovery, nutrition, mental training, and skill development:
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I'm already getting pushback on this one, so to be clear: this is "the case against altitude training," not a balanced summary of the literature. The pro-altitude position is widely accepted, so the goal here is to give some of our assumptions a shake.
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A headline that says "Ultimate Limit of Human Endurance Found" was bound to get my attention. Thanks to all who sent the link! Here are my thoughts on what turns out to be a neat study suggesting that calorie intake is the key limit for REALLY long events.
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Is it more important to get bigger muscles, or to get stronger?. For warding off cognitive decline, per a new study, strength is 10X more important than muscle mass. Same is true for all-cause mortality. which is good news for skinny endurance athletes.
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Neat study: if different people do the same strength training routine, the resulting gains will have ~40X more variability than if the same person does different workouts with each leg. Moral: the details of your workout matter less than you think.
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What's the difference btwn hammering a solo time trial and racing? According to a new study, perceived effort is the same, but "affective feelings" get progressively more negative as the solo trial proceeds. Guessing I'm not the only one who can identify.
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What's your "threshold"? That depends how tired you are. New study finds critical speed starts decreasing after ~80min of effort, which may be one reason a sustainable (sub-threshold) pace can suddenly become unsustainable late in a marathon.
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I was super psyched when Endure made the NYT sports bestseller list for a month back in Feb when it launched. But I'm even more psyched that it somehow just returned to the list. Huge thanks to everyone who recommended it, talked it up, or passed it on!.
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Thrilled to announce my forthcoming book, ENDURE: Mind, Body, and the Curiously Elastic Limits of Human Performance:
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The Danish handball team tried a sports-specific version of mindfulness training. After 6 wks, they improved reaction time, accuracy, and agility compared to the control group. I know mindfulness has been overhyped, but this seems pretty interesting.
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The single most cited paper in sports and exercise medicine, according to a new (and admittedly idiosyncratic) analysis: Gunnar Borg's 1982 paper on perceived exertion. Neat to see just how influential that seemingly straightforward concept has been.
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Lots of debate on whether heat training can boost your performance in cool weather. A new study finds an initial decrease in VO2max during 10 days of heat training, then a rebound boosting VO2max by 4.9% four days after the heat training was finished.
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Some neat data on "fatigue resistance":. The biggest difference between GC contenders and domestiques isn't in their power profile per se, but in how their power profile changes with fatigue. Same for the difference between elite and U23 cyclists.
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To remind myself and other endurance fiends of the importance of building strength, two recent epidemiological studies drive home the long-term health benefits of (a) being strong, and (b) doing resistance exercise.
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An interesting paper argues that overtraining syndrome may reflect problems within the muscles (as opposed to, say, hormonal or psychological issues), maybe linked to oxidative stress and inflammation. Lots more research needed, but worth thinking about.
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After 40, you lose ~0.5-1% of your muscle mass each year. but your muscle *power* drops by 2-4%! That's a problem for healthy aging as well as sports. The trigger may be loss of fast-twitch fibers, which suggest plyos and heavy weights should help.
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An interesting review assesses the "minimum dose" of endurance and strength training needed to maintain fitness during periods of reduced training. Bottom line: you can cut frequency and volume way back, as long as you maintain intensity.
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Which is harder, 30s sprints, 60s intervals, 4:00 intervals, or a 45-minute steady effort? That depends how you measure "hard." A neat study compares the physiological and perceptual responses to four different workouts:
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A big new systematic review tackles the age-old question of differences between treadmill and outdoor running. My takeaway: the physiological and biomechanical differences are subtle at best, but how comfortable you are on the treadmill may matter:
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Riding a bike for 30min 3X/week had significant cognitive and psychological benefits for older adults - and surprisingly, the benefits were similar on e-bikes and regular bikes. Any exercise is better than no exercise, so don't sweat the details.
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Sports nutrition guidelines recommend a max of 90g of carbs per hour. But endurance pros are now pushing to 120g/hr and beyond, and new science shows the body can handle it. The unanswered question, at this point, is whether it makes you faster. More⬇️:.
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Neat study of 25,000 Strava runners finds you get a decent automated estimate of critical speed from training data (fastest 400m, 800m & 5K segments), which in turns gives a good prediction of marathon pace. Turns out my CS, long ago, was 4:41/mile.
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Maximizing endurance is hard; so is maximizing speed. But optimizing the balance between the two, as mid-distance athletes like milers do, is REALLY hard. A great new paper takes a comprehensive look at the physiology of the 800m and mile:.
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At last week's @footwearbiomech symposium, Nike shared data from two internal Vaporfly studies: one varied the curve of (or removed entirely) the carbon fiber plate; the other tested the claim that runners get less muscle damage training & racing in it.
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Cardio vs. weights redux: a new study finds that combo workouts outperform either cardio- or weights-only workout for heart disease risk. That doesn't mean there some magic "muscle confusion" going on, but it's a data point in favor of variety.
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A recent study found that three weeks of super-hard training makes you more likely to seek immediate gratification. No, this isn't the solution to the mystery of overtraining - but it's a neat demo of the blurred lines between mental and physical fatigue.
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