May 4, 2023

Pooping for performance (Yes, there’s a scientific study)

This article falls into one of my favorite categories: “Didn’t see it coming.” Also: “I knew it felt good, I but didn’t know why.”


Researchers tested a group of elite triathletes after “rectal defecation” (pooping) vs no rectal defecation. A good poop decreased systolic blood pressure, increased blood supply in the prefrontal brain, and increased “sub navel oxygen consumption” (oxygen pickup of the leg muscles, a good thing.) Most importantly: “Pre-exercise defecation significantly improved high-intensity endurance performance.”


Conclusion: “This study demonstrated a performance enhancing effect of defecation for elite triathletes.” I think race directors might have to increase their Porta Potty orders. More at J of the International Society of Sports Nutrition (free full text).


Do super shoes change the 180 strides/minute rule?

There’s a modest history of researchers counting stride rates here and there--at elite road races, elite track races, and among recreational marathon runners. They often evaluate footstrike at the same time--forefoot vs midfoot vs rearfoot--although they don’t always use the same definition of these three.


But the running world has turned upside down since the last of these studies was performed. Now everyone’s wearing super shoes. So how does that change things?


To find out, a Spanish team measured foot strike and cadence of runners in the Tokyo Men’s Olympic Marathon in the summer of 2021. About 69% of the runners used a midfoot strike, while 31% landed on their rearfoot, and only 10% on the forefoot.


The low forefoot result made sense to the investigators as they termed it “the most demanding landing technique,” thus not preferable for 26.2 miles. “We can conclude that midfoot striking is the most favorable technique for long distance road events.”


They found that the average stride frequency of the top 8 finishers was 185/minute, while the three medalists averaged 188/min. These results were largely similar to previous study outcomes. Impressively, the Olympic runners maintained their stride frequency across the full marathon distance.


The study provided specific reference to Eliud Kipchoge’s stride rate. Kipchoge ran the second half of the Olympic Marathon about 2 minutes faster than the first half, but he barely changed stride rate at all. Therefore, he got faster by increasing his stride length. In the beginning, middle, and end of the marathon, his stride rate per minute was: 186, 185, 187. More at PrePrints.org (free full text).


How an expert carbo loads: Bagels, bagels, bagels; then graham crackers

Marathon runner and sports nutritionist Meghann Featherstone ran a personal record on the Boston course several weeks ago in her fourth effort there. Here’s how she carbo loaded beforehand, presented in such exhausting detail that you’ll be glad you don’t have to run a marathon after reading her story.


But you might also be convinced to redouble your nutritional focus before your next marathon. More at Featherstone Nutrition.


A hot debate: Should every runner try the marathon?

Here’s an intriguing question that many runners have found themselves facing. The Forum questioner says he/she is happy and healthy running half marathons. But of course it’s impossible not to think about the marathon distance. Is the full 26.2 worth trying? 


Some respondents argue, essentially: If it ain’t broke, don’t fix it. That is, if you’re happy doing what you're doing (nothing longer than a half marathon), there’s no reason to change your habit. Makes sense, right? Hard to argue against this perspective.


Of course, some do. And I like what they say: “Marathons aren’t the only game in town, but I can tell you they are very rewarding, and bring something different to the table.” Also: “You should definitely continue to do things in running that scare you a little or that you’re uncomfortable with.” 


This is one reason ultra running has grown so popular. Many runners are curious, adventurous, and willing to explore the unknown and challenge themselves--all excellent qualities. More at Reddit/Advanced Running.

 

3 ways to strengthen tendons and ligaments

All runners are worried about Achilles tendon injuries, because you can’t go far or fast without a healthy Achilles. Other lower leg tendons are also important: the iliotibial band, the patella tendon, the tendons up high on your hamstring, and down low (peroneal) in your foot.


This article discusses three ways to strengthen these tendons, making them more resistant to injury: with eccentric exercises, plyometrics, and isometric contractions. I had never thought much of using isometric work to begin an injury-recovery plan. Sounds smart. 


Once you feel your muscle has regained good health, you can move on to plyometrics and eccentric strength training. Both have the potential to actually improve performance. More at Training Peaks.


Drink these 3 fluids to live longer

What are the best fluids to drink on a daily basis when you’re not exercising? The author of a big new study has a direct answer for that. “Based on our study I would rank black coffee, unsweetened tea and plain water higher than low-fat milk, fruit juice or artificially sweetened beverages,” he told CNN.“Sugar-sweetened beverages like colas, fruit juices that are high in sugar and whole fat milk that’s high in saturated fat are known risk factors for developing type 2 diabetes and premature cardiovascular disease.”


Of course, you’ll need sugar in your beverages when running, especially marathon-like distances. When you exercise, the body’s biochemistry changes in dramatic ways, and that which is bad while you’re watching TV--sugar--suddenly becomes an essential ingredient that fuels performance.


In the paper behind the CNN report, researchers followed more than 15,000 adults with diabetes for 18.5 years to see how their beverage-consumption affected their development of heart disease and death rates. They found the following hazard ratios for high consumption vs low consumption: 1.20 sugar sweetened beverages, 1.20 full fat milk, 0.98 fruit juice, 0.96 artificially sweetened beverages, 0.88 low fat milk, 0.79 tea, 0.77 plain water, and 0.74 coffee. The ratios were similar for the development of cardiovascular disease.


Also, replacing sugary beverages, artificially sweetened beverages, or full fat milk with coffee, tea, or plain water “was consistently associated with lower all cause mortality.” More at British Medical Journal (free full text).


Females (especially) take note: A plant-based diet could increase bone injuries

The relationship between eating disorders and possible bone injuries has become one of the most investigated and most important in endurance sports. It started decades ago with the Female Athlete Triad and has more recently turned to male eating disorders, especially in sports where low weight might confer a performance advantage such as running and cycling. 


A big question: Do females have greater risk than males? Here are several recent studies that increase our understanding of bones and vigorous exercise.


This “critically appraised” review of the topic found “low-moderate evidence” of a link between eating disorders and bone injuries in female athletes. Less is known about males. More at J of Sport Rehabilitation.


“Bone stress injuries have plagued the military for over 150 years,” afflicting up to 10 percent of new recruits. The primary risk factor is “too much training, too soon.” Women have about twice the bone injuries of men. Good nutrition can help but also “exposure to stress, sleep loss, and medication is likely harmful to bone.” More at J of Science & Medicine in Sport (free full text).


A study of 16,000+ U.S. adults from 2005 to 2018 found “hidden dangers” to a plant-based diet on bone health. Specifically, plant-based diets, which are often recommended for their potential health and environmental benefits, are “associated with decreased bone mineral density in a nationally representative population of U.S. adults.” The most protective foods are: vegetables, refined grains [yeah, I don’t get it either; but that’s what they reported], animal fat, eggs, and meat. More at Nutrients


Here’s a super deep dive into sacral bone stress injuries in runners with specific advice on training and diet errors that might be causative factors. As well as solid, healthy guidance on getting back onto the road. More at Pogo Physio.


Lastly, a group of world-renowned exercise nutritionists have concluded that consuming sufficient carbs, even more than total calories, is the key to maintaining strong bones in endurance exercisers. In a 6-day study with elite race walkers on a low-calorie diet, they found that: “Carbohydrate may be key for maintaining bone formation during prolonged exercise, but both overall energy and carbohydrate are necessary to support bone formation at rest and limit exercise-related bone resorption.” More at J of Bone & Mineral Research (free full text).


What’s the truth about exercise and improved brain function?

When he’s got time left over from his work at Outside Online, Toronto’s Alex Hutchinson occasionally writes newspaper articles. Here he looks at some recent reports that have cast doubt over one of our fondest beliefs--that exercise is as good for the brain as it is for the eyebrows-down.


One rigorous review found only “negligible” evidence that exercise produces cognitive benefits. On the other hand, another high-quality review used Mendelian randomization to find “significant associations” between moderate and vigorous exercise (like running) and “increased cognitive functioning.” [Mendelian randomization is a statistical technique that edges close to cause-and-effect by using the known genetic makeup of subjects.] The paper observed no evidence of the same from “average physical activity,” ie, vacuuming the house, mowing the lawn, etc. More at The Globe & Mail.


If you’re a marathon runner, you might be doing good work for your hippocampus--the part of your brain responsible for regulation of stress, and also spatial navigation. At least that was the finding that popped out from MRI imaging of 73 marathon runners vs 52 healthy, matched controls. The marathoners seemed to have “a hippocampal volumetric reserve that protects against age-related hippocampal deterioration.” More at Medicine & Science in Sport & Exercise.


SHORT STUFF you don’t want to miss

>>> Run for the future: More and more shoes and running fitness apparel are made from recycled and sustainable materials.

>>> Nothing special: Muscle injuries (and concussions) are more prevalent in high schoolers who specialize in a particular sport and/or spend more than 8 months per year in one sport.

>>> Outdoors vs treadmill: Running outdoors provides “greater feelings of revitalization and positive engagement, decreases in tension, confusion and anger and depression, and increased energy.”


GREAT QUOTES make great training partners.

“The secret of getting ahead is getting started.”

--Mark Twain


That’s it for now. Thanks for reading. See you next week. Amby