Each week, Boston Marathon winner Amby Burfoot, also the world’s most experienced running editor, curates the latest and most useful content on running and health from around the internet. “I spend hours finding the best new research and articles, so you can review them in minutes.”
THIS WEEK: Jumping exercises could prevent bone injuries — and make you faster. Training with heart rate variability boosts performance. Motion is lotion. Head cooling improves 5K times. The marathon has two walls. And more.
Jumping exercises to prevent bone injuries
I’m going to give this paper a little more space than others, as it’s potentially the most important I’ve read this year. Bone injuries are a serious problem for young endurance runners who are often tempted to lose weight to improve performance. Teenage girls may face a particular risk, as missed menstrual periods are linked with missed opportunity to optimize lifelong bone strength.
What’s the answer? A focus on healthy eating and energy balance comes first. But a team from England’s Loughborough University has now proposed another strategy — using low-rep, high impact activities (basically, jumping exercises) to build the bones beyond what running itself provides. The simple CMJ (countermovement jump) is easy to find on YouTube, and has been shown to increase bone strength.
In an email to me, lead author Mark Hutson said that forward-and-back, and side-to-side jumps could also be a good idea, though he noted that CMJ (double-leg) jumps might provide the most force and greatest stimulus. A modest number of jumps could go a long way toward building healthier bones, and the jumping exercises won’t take much time, detract from other training, or burn though many calories on their own.
Note well: This is not a proven practice. But it makes a lot of sense. More at Sports Medicine.
Jump training improves 5K times, meta analysis
Running is a form of hopping or jumping from one foot to the other, so it makes sense that jump training could improve running performance. But the link has been little studied, and often with small sample groups. This meta-analysis dug into 21 prior papers, and concluded that “jump training is effective in improving athletic performance in endurance runners.” Try a mix of slower, more powerful jumps (hill bounding) and quicker ones (hot feet). And, of course, rope jumping, which I am going to master this year. Really, I am. More at J of Sports Sciences.
Heart rate variability training appears to work
Heart rate variability sounds like a bad thing, but it’s actually good. A low HRV is associated with increased risk of disease, depression, even death. A high HRV indicates a more relaxed, healthier state. New wearables like the Whoop device have made HRV more accessible to individuals, and have spawned more research. Here, a systematic review of training practices finds that “higher training intensities and frequencies are more likely to improve HRV.” Another systematic review looked specifically at results from endurance-training programs. It concluded that that those who followed HRV-guided training performed slightly better than those on “predefined training,” though the results were not statistically significant. HRV training was also associated with “fewer who respond negatively and more who benefit.” More at J of Sci & Med in Sport.
Summer heat has a positive side
Many endurance athletes find summer a depressing time. The heat and humidity make normal training impossible, and workouts feel slow and debilitating for weeks if not months on end. Yes, the heat sucks when you’re running. But it can also improve your performance (on an upcoming, cooler day). Heat training is like altitude training, only for lowlanders. This new paper concluded that hot-weather training “may be useful for inducing adaptations relevant to performance in temperate conditions.” More at Physiological Reports.
Head cooling pre-race improves 5K time
You’ve probably read a number of stories about pre-cooling before racing on hot days, and you might remember that Deena Kastor and Meb Keflezighi wore ice-vests before running the 2004 Athens Olympic Marathon, where both won medals. Now it turns out that “head cooling” is another effective strategy, presumably with a modest ice application under a cap. In this Brazilian study, subjects raced about 6% faster with head pre-cooling. More at Scandanavian J of Medicine & Science in Sports.
New research fine tunes dehydration-endurance connection
You wouldn’t expect Gatorade to present the case for less hydration, and of course the sports-drink giant doesn’t. Here, however, G offers new dehydration insights based on recent, more advanced research. Past papers might have suffered from “not being blinded” and “using uncomfortable dehydration methods.” Newer work still suggests that losing more than 2% of your body weight is likely to impair endurance performance. It also acknowledges that “some habituation to dehydration is possible,” although that’s not the same as achieving optimal performance. Kudos to Gatorade for making this new summary widely available. More at Gatorade Sports Science Institute.
Make your drink pink
According to this new study, it’s not just the contents of your sports drink that can boost performance. It’s also the color, and pink seems to be a winner. On a 30-minute treadmill test, subjects ran 4.4% farther and faster after “mouth rinsing” with a pink, zero calorie beverage than with a clear version of the same beverage. They reported more pleasure as well. The researchers chose pink as it is known to increase the perceived sweetness of a food or beverage. More at Frontiers in Nutrition.
Motion is lotion
I try not to overemphasize the multiple benefits of exercise, but, frankly, it’s tough. Take fibromyalgia for example — a condition characterized by near-constant muscle pain. So you might think that exercise would be the worst possible prescription. Wrong. Several major reviews have found that “supervised aerobic and resistance training programs” reduce pain and improve life quality. Go figure. But also, get moving. More at Joint Bone Spine.
Bad news: There are two walls in the marathon
The emergence of wearable sensors has given running scientists more tools than they ever imagined before. Now they can uncover previously unknowable data. Like, for example, how much we change pace in the marathon. Everyone knows most marathoners slow down after they hit the wall at 20+ miles. This new paper says we slow once before that as well, at about 16 miles. Our stride gets slower, for a variety of reasons. What can you do? Just train and fuel better. More at Int J of Sports Medicine.
Post-run carb intake for recovery
I’ve never been a big fan of that run-and-then-eat-something immediately dictum. I mean, I’m mortal. Unlike elites, I’m not doing another killer workout in 4 hours; I can take my time. Still, a new review suggests optimal glycogen recovery after “ingesting at least 1.2 g of carbohydrate per kilogram body mass per hour” for several hours. (That’s 2.2 carb calories/pound, or about 330 calories/hour if you weigh 150 pounds). If you want to improve fat-burning, you can try to restrict carbs during this period. More at Current Opinion in Clinical Nutrition & Metabolic Care.
Super shoes keep getting faster
Which means that the runners wearing them are also faster. Running scientists and statisticians just can’t get enough of these comparisons of race times pre-Nike Vaporfly shoes and post-Vapors. World Athletics investigated global top-20 times in three distances (10,000, half-marathon, marathon) from 2012 to 2019, and found that women improved more on average than men (1.7% to 2.3% vs 0.6% to 1.5%). Cornell statisticians looked at tens of thousands of internet photos of North American marathon runners (men under 2:24 and women under 2:45) and the shoes on their feet from 2015 to 2019. They concluded that the men improved slightly more than the women. Both groups, amazingly, pinned women’s marathon improvements at 2 minutes and 10 seconds. More at Podium Runner.
Omega-3s may not diminish risk of atrial fibrillation
Veteran male distance runners are thought to have an increased risk of atrial fibrillation, a heart arrhythmia associated with stroke incidence. For many years, consumption of omega-3 fatty acids (fish oil) has been proposed as a deterrent. Newer, higher-quality research is not confirming such a benefit. A new meta analysis of RCTs actually found a 37% higher incidence of afib among those taking omega-3 fatty acid supplements. More at European Heart Journal.
“Moving and meaning” are often closely related
NY Times “phys ed” columnist Gretchen Reynolds and I once worked at the same wonderful health-fitness company, Rodale, Inc. Last week she dug into a fascinating study that I had recently noticed as well. It looked for links between “moving and meaning,” as Gretchen nicely phrased it. The results were positive. “People who started off with active lives generally showed an increasing sense of purpose over the years, and those whose sense of purpose was sturdier in the beginning were the most physically active later.” Yes, you can do good for others and for yourself. In fact, you should do both. You will flourish, the world may become a better place. More at NYTimes and J of Behavioral Medicine.
Post-long run cravings
This isn’t expert advice or anything like that. It’s 800+ comments on a Reddit thread asking, “What do you crave after a long run?” My answer would have been a root beer float, but the largest number of “votes” went to beer, pizza, ice-cold lemonade, various kinds of smoothies, and a whole lot more, including a nap, Netflix, and a “new set of legs.” More, just for fun, at Reddit.
SHORT STUFF you’ll want to know
GOOD QUOTES MAKE GREAT TRAINING PARTNERS
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