MARCH 6, 2024 xx tk
“Train Your Brain” A New (And Better) Way
Here’s a delicious, memorable, and highly useful quote from coach-endurance physiologist Alan Couzens. I’d say it’s even worth printing out and sticking on your refrigerator.
It goes like this: “Your brain and your soft tissue work on very different timeframes.” You could also rephrase it as: “Listen to your body … below the neck, not above.”
Of course, there are times when the brain is a good monitor. This is especially true when it registers a high Relative Perceived Exertion for runs and other tasks that should be easy for you to perform. At these times, you need to back off.
However, many of us pay too much attention when we hear a little voice saying: “You’re not tough enough to be good.” Or, maybe: “Only the gutty survive.” Or: “When the going gets tough, the tough get going.”
This is the voice of false narratives that we’ve somehow picked up from our parents, siblings, friends, teachers, and larger social environment. We all harbor a few such narratives. But we’d be happier, healthier (and maybe faster) without them.
Couzens wants us to ignore false narratives that tell us to run more and harder despite sore muscles and achy joints. It’s an excellent message. You’ll fare much better by running less and slower. At least until your lower body tissues are fully recovered. More at Twitter/X Alan Couzens.
New Report (From Harvard) On Plant-Based Diets And Bone Health
A fair number of runners follow a largely plant-based diet, perhaps because they’ve read studies showing this a healthy alternative to meat-heavy diets. Or perhaps because they consider it a more environmentally-friendly way to eat.
However, other runners shy away because they fear bone-stress injuries if they go on a plant-based diet. Indeed, some prior studies have shown lower bone density and more hip fractures among those who eat mostly plants.
Now a big new report from top Harvard researchers offers reassurance to plant-based runners. It involved more than 70,000 post menopausal women from 1984 through 2014. This is a particularly susceptible group.
Result: “Long-term adherence to a plant-based diet was not associated with the risk of hip fracture.”
Also, perhaps unexpectedly, there was little difference between those who followed a relatively healthy plant diet vs a less healthy one. The healthy approach contained more “whole grains, fruits, vegetables, nuts, legumes, vegetable oils, and tea or coffee.” The unhealthy one had “fruit juices, sweetened beverages, refined grains, potatoes, and sweets or desserts.”
However, the healthy vs unhealthy diets did produce significantly different results when the researchers looked at just the most recent 2 years. In that case, the Healthy Plant diet decreased hip fractures by 21% and the Unhealthy Plant Diet increased fractures by 28%.
Interpretation: A plant based diet--this was not a strict vegan diet but included some eggs and dairy foods--is sufficient to maintain strong bone health. To play it safe, you’d be smart to focus on the healthiest aspects of plant-based eating rather than the junkier, more processed approaches. More at J of the American Medical Association with free full text.
Exercise And Mental Health--The Now And Future Frontier
I’ve been following running and exercise studies in the scientific literature for 50 years. And here’s the biggest change that has occurred: A half century ago, the papers were all about physical outcomes, especially improvements in heart health and optimal performance.
Now, the biggest, most significant papers deal with exercise and mental health. No one saw that coming in 1970, but what a huge and important development. In this era of high-stress, high-depression, and high-suicide rates, mental health has achieved parity with physical health as a global concern.
The British Medical Journal just published possibly the best-yet review of exercise and depression. It’s a meta analysis and systematic review of only RCTs that investigated exercise and depression.
Conclusion: “Exercise is an effective treatment for depression, with walking or jogging, yoga, and strength training more effective than other exercises.” Also, exercise effects “were comparable to psychotherapy and pharmacotherapy. Finally, “Exercise worked better when more intense.”
I frequently point out that even slow running and walk-running generally reach the level of vigorous exercise, as defined by physiologists. Walking counts as moderate exercise. That’s why the federal activity recommendations can be met by just 75 minutes/week of running vs 150 minutes of walking.
The new report pulled together results from 218 unique studies that followed 14,170 subjects. Impressive!
More at British Medical J with free full text. Also, here’s an excellent summary article at Physiologically Speaking.
On a related topic, here’s a systematic review of suicide among elite athletes. Conclusion: “Elite athletes generally demonstrate reduced risk of suicidal ideation, suicide attempt, and suicide completion compared to the general population.”
Of course, this is an outcome based on “averages.” In real life, every athlete and every situation is different, and parents, coaches, and friends should always stay alert to mood changes of athletes they’re close to. More at Sports Medicine with free full text. And see below in this newsletter for an informative graphic.
A Surprising Way To Reduce Tripping And Falling On The Run
You’ve gotta love a research paper that asks and answers an important running question that has almost never been tested before. Especially if the paper begins with a couple of catchy sentences.
Like these two: “To read this article, you have to constantly direct your gaze at the words on the page. If you go for a run instead, your gaze will be less constrained, so many factors could influence where you look.”
No argument there. You can’t read a magazine or a digital screen while looking up at a rainbow. On the other hand, you can look at a rainbow while running. In the Olympics, we often see top runners glancing up at a Jumbtron to see how their race is going.
So why is looking down vs looking up a good research question for runners? Because the roads and trails are covered in cracks, bumps, potholes, stones, roots, and much more. And if you’re looking up, you’re more likely to trip and fall over one of these obstacles.
Which brings us to the research question in the current investigation: Do you pay more attention to the ground in front of you when A) running alone or when B) running with a training partner?
I felt confident about the outcome. I guessed A. I was wrong.
Here’s what actually happened. A Dutch research team asked 12 subjects to run on a path two times: once alone, once with a running partner alongside. Subjects were fitted with an eye tracking instrument that measured where they were looking.
Result: The runners were more likely to look directly ahead (and downward toward the path’s surface) when running with a partner than when running alone. The researchers believe this happened because there is more chance of an accident when two people share a path. So each individual must pay more attention to where they are going.
Conclusion: “People appear to judge there to be more need to look where their feet will be placed when running alongside someone else.” Chalk up another good reason to run with a training partner. Also, if you do fall, a training buddy can pull you back to your feet. More at Perception with free full text.
What Serious Science Says About Ice Baths
In this article, the Skeptical Inquirer Nick Tiller, PhD, takes a hard look at the exercise benefits of ice bathing. He concludes that Wim Hof and the Tik Tok crowd are promoting an activity supported by their subjective belief in the practice. Not by good evidence.
To bolster his arguments, Tiller reviews both the physiology of muscle-fiber growth through training, and the physiology of muscle recovery. He also links to 2 recent meta-analyses.
Some muscle soreness is inevitable if you exercise, especially when you’re just starting out. “Just as a rubber band becomes frayed if you continually stretch it under load, your muscles sustain minuscule tears if they’re stretched too far or exert too much force.”
Next, the muscles adapt by “laying down new structural proteins, like a construction crew assembling steel beams to support the infrastructure of a building.”
That sounds good, normal, natural, and a positive response. However, “Ice bathing fundamentally inhibits this process.” That’s why it might interfere with the very training effect you’re hoping to build through your workouts. Ice baths also blunted “the activation of key proteins and satellite cells in muscle.”
Nonetheless, in television coverage of the recent World Indoor Championships, we saw photos of world-record sprinter Femke Bol soaking her legs in an ice bath between her races. This acute practice has been supported for reduction of pain and swelling in the short term when you have to go to the start line again very soon. However, it’s not the best long-term practice.
At any rate, the many supporters of ice baths had plenty to say to Tiller on his Twitter/X feed. Especially those espousing “mental and emotional benefits.” Hey, if you think it feels good, go for it. But don’t expect to get stronger or faster. More at Skeptical Inquirer.
Good News For Runners With Long Ground-Contact Times
Running economy is considered a pivotal measure of distance-running success, and is often related to stride biomechanics. RE is important because you can continue to improve it over many years even after you have reached a ceiling for vo2 max. Some but not all studies have found that a shorter foot-contact time is linked to improved running economy.
However, a new paper from Japan produced the opposite outcome for “17 highly trained runners.” They were capable of running times in the low 14’s for 5000 meters, and the low 29’s for 10,000 meters. Ten were midfoot strikers, and 7 rearfooters.
This lab research looked for links between running economy, contact times, footstrike landings, and upper-leg musculature.
Result: Longer ground contact time improved running performance and running economy. Footstrike pattern had no impact on these findings.
Lastly, and uniquely in my reading of running-economy papers, the researchers found an association between smaller upper-leg muscles and higher running economy. (Put the other way: Larger quad and hamstring muscles decreased running economy.)
This doesn’t mean that strong quads and hamstring are unimportant in distance running. It just means that you don’t want to bulk up with extra muscle above the knees.
Conclusion: “Large cross sectional area of knee extensor muscles results in short ground contact time and worse running economy.” Conversely, small thigh muscles are linked to longer ground contact time and better running economy. More at J of Strength & Conditioning Research.
Do Women Gain More From Their Workouts Than Men?
Several weeks ago I saw headlines declaring “Women get more benefit from exercise than men.” I looked briefly at the study in question, but it didn’t make the final cut here at RLRH.
I don’t actually remember why. It was probably a simple matter of more compelling stories about more serious training and nutrition.
Last week I came across several reports criticizing the original study, published by the Journal of the American College of Cardiology (with free full text.) These were more interesting than the initial report because they raised compelling arguments.
You might have seen one of the original reports also. Here’s why you shouldn’t believe what you read then.
The main problem: The study was based on self-reported physical activity--a notoriously bad way to measure exercise. Sometimes it’s all you’ve got, and there’s no reason not to do studies based on self-reported exercise. But you have to be careful about your conclusions.
Especially if you’re trying to suss out differences between the sexes. Why? Because men are known to lie more about exercise than women. One prior study based on actual objective exercise measures showed that men reported 47 percent more exercise than women when in fact they were doing the same amount as the women.
If men aren’t doing the exercise they claim, then they obviously aren’t reaping equivalent health benefits. So, despite the study in JACC, it’s unlikely that women benefit more from exercise than men. They’re simply being more honest in their self-reports of daily activity. More at ConscienHealth.
How To Tell That A Teen Runner Might Be Facing Menstrual Dysfunction
It’s sometimes hard to tell when a young female runner is under-fueling (Low Energy Availability), and brief periods of LEA are often well tolerated. On the other hand, missed menstrual periods are a clear sign of female physiological dysfunction. Missed periods must be taken seriously, as they can lead to short-term and life-long health issues, particularly bone problems.
For that reason, a group of Italian researchers conducted a study with runners “of fertile age” to see how many had regular menstruation (about 60%) and how many had irregular periods. The 40 percent with menstrual irregularities represent about double the prevalence in the full population. The researchers asked their subjects about their training, diet, and other factors to see what links they might uncover.
The average weekly mileage was 46 km--about 29 miles per week. Caloric intake was below the suggested amount (2000 calories/day) in 51% of subjects, but did not distinguish between atypical menstruation and normal menstruation. Nor did BMI. Also, the injury rate was the same in those below and above 2000 calories/day.
Key result: A training distance over 40 miles per week was associated with menstrual dysfunction, whereas other measured factors were not.
Conclusion: “The variable of kilometers run per week was associated with menstrual irregularities with statistical significance.” Also women with menstrual irregularities tended to train more than 5 days a week, and to include additional non-running workouts in their training program.
Application: In this report, total running mileage (along with total runs/week, and number of extra non-running workouts) provided the most powerful link to menstrual problems. Adolescent females should be careful about high-mileage training. More at International J of Sports Medicine with free full text.
The Latest Attempt To Explain East African Marathon Dominance
Humans are good distance runners, relative to many other animals, because we’ve evolved efficient means of body heat dispersal. Most of this comes from our low body hair covering and high sweat rate.
These factors have been recognized for a long time. They’ve received more coverage since Dennis Bramble and Daniel Lieberman published their paper, “Endurance running and the evolution of Homo,” in Nature in 2004.
I’m not sure, however, if anyone has extended this thesis to explain the marathon excellence of runners from East Africa. Are they the best Homo runners because they have the best heat-dispersing bodies?
That’s the basic claim of a modest paper in a little-known journal by several researchers from Kyrgyzstan. No, I’m not messin’ with you. This team is interested in “one poorly studied physical peculiarity of the human body, namely its heat-conducting ability.”
The authors claim to be experts in “the variability of chromosomal Q-heterochromatin regions (Q-HRs) in human populations.” They have observed, for example, that peoples living in mountainous regions have a low Q-HR, and people from high, arid regions have a high Q-HR.
Q-HR is basically a measure of “body heat conductivity.” It is notable, the new paper states, that “a sportsman with high heat conductivity cannot make much progress in mountaineering and water sports because their body cools rapidly. However, this sportsman can be more successful in sports, which require effective heat-loss.”
We all know that the marathon is, in part, a fight against rising body heat. It’s also impossible to miss the dominance of East African runners in the marathon. Specialists in exercise genetics have spent the last 30 years looking for an explanation. They’ve mostly failed.
Now we’ve got a new candidate: high body heat conductivity as measured by Q-HR. Maybe East Africans have a higher Q-HR than other groups.
The authors conclude: “Perhaps our ancestors acquired their unique ability--endurance running--when they were struggling for existence on the African savannahs.” More at Medical & Clinical Research with free full text.
A Cool Graphic From That Exercise & Depression Review
Here’s one of several interesting graphics from the above-mentioned article on exercise vs depression. This line shows that higher intensity exercise is more effective at lowering depression than less intense exercise. More at British Medical J with free full text.
SHORT STUFF You Don’t Want To Miss
>>> Train your gut: Can a probiotic supplement lower your risk of GI distress on the run?
GREAT QUOTES Make Great Training Partners
“Running allows me to set my mind free. Nothing seems impossible, nothing unattainable.”
--Kara Goucher, Olympian, book author, podcast host, TV commentator