After five years of Sweat Science, a summing-up of what really matters.
This will be my final Sweat Science column for Runner’s World, which has led me to spend a lot of time in recent weeks reflecting on the lessons of the past five years. Since February 2012, I’ve been diving into every new sinkhole of a topic where the riddle of endurance meets the backhoe of science.
In the day-to-day pursuit of interesting or surprising new findings, it’s easy to get lost in the weeds – to focus on the latest single study rather than the broad patterns that emerge over time. So, for my final column, I’m going to try to synthesise seven key messages that I’ve found myself returning to over and over again in this space. Here’s what writing Sweat Science has taught me:
1. Running is good for you “in moderation”, which is defined as “a lot more than you’re doing”.
Some of my most passionately debated posts were written in response to the surge of “running too much will kill you” stories that flooded the media between 2012 and 2014. As a runner and running journalist, my own biases were obvious, but I tried to evaluate the scientific evidence as clearly as possible – for my own self-interest and longevity, if nothing else. Here’s the in-depth final summary I wrote last year on the debate about running and heart health.
In many ways, the debate centred on the question of how much is “too much”. It’s fairly obvious that running, say, eight hours a day isn’t likely to carry any additional health benefits compared to running one hour a day, and may well make you less healthy. But are there downsides, as some studies argued, to running even relatively modest amounts like 32 kilometres per week?
Without getting bogged down in all the claims and counterclaims again, my take is that you can get most of the health benefits of running with a fairly modest program – say 20 to 30 easy minutes, five days a week. I suspect that a more rigorous program, closer to an hour a day with some more intense interval workouts, will offer some additional benefits in the long term. Beyond that, you’re doing it because you enjoy it – but even then, you’re not running yourself into an early grave.
Various other supposed dangers of running are also oversold. I’ve accepted that no matter how often I write about research demonstrating that runners are, if anything, less likely to develop knee osteoarthritis than comparable non-runners, people will continue to disbelieve it. That’s okay, but don’t let anyone scare you away from running to preserve your joints. And don’t even get me started on half-baked, pseudoscientific claims like the idea that moderate running will trash your thyroid or make you fat.
The bottom line? Endless studies show that running (and endurance exercise more generally) helps reduce the risk or severity of conditions ranging from glaucoma to Alzheimer’s – and the more running you do, the better off you are. It makes you feel better, too. So keep running, and tune out the noise.
2. If it comes in a bottle, it’s probably not going to make you faster or healthier.
I’ve taken plenty of pills over the years. In university, in addition to multivitamins and antioxidants and occasional echinacea, I downed a foul-tasting botanical concoction called Matol, given to us by our track coach, every night. Later, struggling with a case of runner’s knee, I poured untold dollars into glucosamine and chondroitin supplements.
Did they work? Well, whenever I caught a cold, I eventually recovered. My knee, too, eventually healed. That’s the natural history of most conditions, and it’s one of the reasons supplements are a multibillion dollar industry. But the actual evidence tells a different story.
When I first started writing Sweat Science, one of my biggest interests was discovering and writing about the newest and greatest performance-boosting supplements. But as time went on, I noticed that the encouraging results of small studies on hot new supplements never seemed to be duplicated in bigger studies. And I also started seeing data suggesting that many supplements, including common antioxidants like vitamin C, can have negative effects like inhibiting the fitness gains from training.
There are a few exceptions: caffeine works; beet juice seems to work; maybe beta alanine and baking soda do too. For those of us who live far from the equator, vitamin D pills in the winter may be a good bet. But in general, studies find that micronutrients in pill form seldom live up to the health benefits they provide in the context of whole foods. Eating fish is better than taking fish oil; nitrate-rich beets are better than nitrate pills.
In fact, research into the “licensing effect” suggests that the mere act of taking a pill will make you less likely to follow through with more effortful forms of healthy behaviour. You may take a multivitamin as “insurance” against not getting enough fruits and vegetables – but in doing so, you give yourself permission to not bother packing that carrot and apple in your lunch.
The best approach, in my view, is to throw away the crutch. You don’t need pills to run fast, and for the most part they don’t work anyway. Focus instead on eating well, getting enough sleep, training smart, moving around throughout the day, and getting outside.
3. The best technology for tracking and guiding your runs is the device between your ears.
I love neat tech gadgets as much as the next guy, and I’ve written a lot about using data like heart-rate variability to guide training or monitor fatigue, and the uncanny ability of GPS watches to estimate VO2 max. But the truth is that, even as technology has advanced over the past five years, my faith in its ability to yield actionable insights has declined.
It’s not that I think technology and its associated data are “useless”. Instead, I think our innate abilities to monitor pace, fatigue, training load, and other parameters are generally underestimated. One of the most interesting studies I wrote about was a 2015 meta-analysis of 56 training studies that found that subjective measures (basically asking “how do you feel?”) were able to detect changes in training load more sensitively than objective measures (hormone levels, markers of inflammation and muscle damage, immune function, etc.).
I also think running coach Steve Magness had a point when he wrote that running with GPS “slackens the bond between perception and action”. Instead of speeding up or slowing down based on how you feel, you do it based on the feedback from a device that’s providing an imperfect estimation of how you feel. Do that enough, and eventually you may become less able to detect the subtle differences in feel that can be the margin between an okay run and a great one.
This isn’t a Luddite argument to smash your machines. There are times when a GPS device can be a great training aid, like if you’re doing a long tempo run alone on an unfamiliar course. And it can be a lot of fun to sift through the mountains of data collected by high-end watches and fitness monitors. But ultimately, you need to make sure you’re also spending enough time monitoring the signals from your own body to able to interpret them correctly when it counts.
4. You probably got injured from doing too much, too soon.
I’ve written a lot about injuries, for the simple reason that runners get injured a lot. Is knee pain caused by weak hips]? What are the six key warning signs that precede stress fractures? Do men and women get the same running injuries?
There are, indeed, a lot of subtle factors that can affect your risk of injury. But if you push any injury researcher hard enough, they’ll tell you that overuse – doing too much, too soon – is the underlying cause in the vast majority of cases. One estimate I heard from University of Calgary running guru Benno Nigg was that “too much, too soon” accounts for 80 per cent of running injuries.
There are some subtleties here. One series of recent studies argues that “overuse” is a misleading term, since the problem isn’t necessarily that you did too much. It may be that you did too little in previous weeks, so that what should have been a manageable load became unmanageable. A better term, these researchers argue, is “training load error”.
This doesn’t mean that the various injury prevention and treatment options you hear about are worthless. In fact, in one of my favourite Sweat Science posts, I argued for a “Broken TV” approach to injuries in some contexts. Sometimes it’s worth banging on the box just to try to shake something up.
But ultimately, you’ll be doing yourself a favour if you attribute incipient pains to training errors – and respond appropriately by backing off – rather than assuming you can keep training if you do a few extra warm-up exercises or stretch more. That, I believe, is why a recent study found that even very obvious advice, delivered by a machine, can reduce running injures. We know the culprit here; sometimes we just need a reminder.
5. The magic workout, shoe, or superfood is whichever one you’ve been ignoring lately or have never tried.
Sure, I love to dig into the details of workouts – whether it’s better to do an odd or even number of intervals, whether to run in the morning or evening, whether the classic 20 x 400m workout has mystical powers, and so on. Every workout has different charms, different benefits, and different horrors – and that’s kind of the point.
Over the course of my own running career, I was lucky enough to train with a series of great coaches, each with different perspectives and approaches. Each time I switched, I initially struggled, then eventually improved and became convinced that the new coach’s “missing ingredient” – long hard intervals with complete recovery, or 16K progression runs, or cruise intervals with fast-jog recoveries – had made me better. And in a sense that’s true. But in hindsight, I don’t think it’s because of the intrinsic physiological characteristics of the workout. It’s because it was a new stimulus for me.
I don’t want to oversell the benefits of novelty. Running is a simple sport, and its essence requires simply that you do the work. Some of the best runners in history have had mind-numbingly simple and repetitive training plans.
Still, I think there’s something to the idea of challenging yourself in new ways, both mentally and physically, particularly if you’ve been running for many years. Each workout has subtly different physiological effects, and those effects obey a law of diminishing returns after you’ve been doing the same thing for a long time.
And I think this principle applies more broadly than just to workout choice. There’s evidence, for example, that rotating between different types of running shoes on a daily basis is associated with lower risk of injury, presumably because you’re experiencing slightly different stresses with each shoe rather than the same ones over and over again. For food, too, the healthful benefits of any particular superfood pale in comparison to the overall rewards of a varied diet. Bottom line: Mix it up.
6. You can probably run better; start by running more.
There was a time, not so many years ago, when any mention of “ideal” running form or “proper” running shoes would spark a screaming match in the comments section of the blog. While passions have mostly cooled, I think running science is better off in the wake of these debates. We’ve challenged a lot of assumptions that used to be taken for granted, and the running world looks different than it used to. Personally, for example, I now run in lighter shoes (at least some of the time) than I did ten years ago.
That said, I’m not sorry to see some of the dogmas that arose in those years finally fade away. One of my biggest frustrations was the widespread belief that runners of all shapes, sizes, and speeds should maintain a cadence of 180 steps per minute, regardless of context. I no longer hear that claim as frequently these days; similarly, the tone of debates about foot strike and minimalist shoes seems less dogmatic.
Does running form matter? Sure. There’s a difference between efficient and inefficient running styles, even if those differences aren’t as readily detectable with the naked eye as we might like to think. And it’s possible – though still not reliably demonstrated, in my view – that relatively simple gait exercises and adjustments might make your stride more efficient and easier on the body.
But the truth is that most studies that find gross inefficiencies in running form involve relatively inexperienced runners. And the best way to improve those inefficiencies is simple: run more. Don’t worry about fine-tuning the upholstery on the seats of your rocket ship until after you’ve built the engine.
7. You’re capable of more than you think, but it will take time to get there.
If there’s been one recurring theme in the topics I’ve covered on Sweat Science, it’s been the role of the brain in determining the limits of endurance. I started out curious about things like VO2 max and lactate threshold, but the most interesting studies I found were those that explored why, in two people with seemingly identical physiology, one might consistently triumph.
That, in fact, is the topic I explore in my forthcoming book, Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance, and it’s been an all-consuming interest for nearly a decade. What once seemed like a hokey self-help idea to me—that motivation and self-belief have a measurable effect on performance—now seems clear to me.
But it’s not a switch you can flip on at will. Pushing back your mental limits is as laborious and time-consuming a process as pushing back your physical limits, and self-belief has to be earned. One of the aphorisms I like to cite is that most people overestimate what they can achieve in the short term (hence all the injuries in couch-to-5K runners) but underestimate what they can achieve in the long term.
So my parting advice – to myself as much as to anyone else – is to continue to set ambitious goals, to identify reasonable intermediate steps leading to those goals, and to enjoy the process of chasing those intermediate goals regardless of the outcome. For me, that means aiming for a sub-16:00 5K next year – a goal that will dictate the various milestones I’ll need to pass along the route in the coming months.
Thanks very much for reading over the past five years (or more, for those who read Sweat Science before it moved to Runner’s World!). I’ve enjoyed the ride and the conversations, and look forward to sharing news about my next adventure on Twitter and Facebook in the next few weeks.
