MAY 30 2024 xx
Pre-Race Pooping Boosts Performance (Not A Joke)
Here’s a first sentence from a scientific abstract that kept me reading: “Constipation is correlated with diminished cognitive function, revealing a possible rectum-brain connection.”
Really? I know quite a bit about the gut-brain connection, because a dozen years ago I suffered from a serious gut-brain illness. (Too long a story to tell now.) But I had never heard about the rectum-brain connection, which I’m now going to call the butt-brain connection. Because, why not?
We still have a lot to learn about how cognitive function affects physical endurance. But few doubt that there is some degree of connection. “The brain is the number one organ that determines your performance and decides how long you can persist your muscle contraction.” explains Chinese professor Chia-Hua Kuo in this article at Triathlete. He’s currently a visiting scholar at William and Mary University.
In a previous experiment (free full text) last year, Kuo had shown that defecation before a cycling time trial dramatically improves performance in the time trial. In this new paper, he wanted to see if the improvement might have come from enhanced butt-brain performance. The outcome: Yes!
Here are the key details: 13 elite triathletes took the mentally challenging Stroop test after one of three conditions: not defecating, defecating with the assistance of a magnesium oxide supplement, or defecating without the magnesium oxide.
Result: 100 percent of subjects improved on the Stroop test after magnesium oxide + defecating, and 69% (9 of 13) improved after defecating without the magnesium supplement.
Also, a full body PET scan showed that the butt region was as active as the brain during the Stroop test. Here’s a 3-second video if you'd like to view it.
Conclusion: “The result of this study suggests an unexplored causal link between the state of the rectum and cognitive performance.” Furthermore: “Magnesium supplementation to improved rectal emptying presents a novel application for optimizing cognitive function in athletes navigating intricate racing conditions.” More at Sports Medicine & Health Science with free full text.
Good News: Super Shoes Could Lower Injury Rates
Super shoes first hit the sports science headlines in 2017/2018 when it was shown that they could improve performance of elite marathon runners. Almost immediately, the shoes began appearing on the feet of top athletes at all major marathons.
Why? Because they were provided for free to these elites, who then had a better chance of winning prize money in their big races. A no brainer.
But midpack recreational runners who finish in 3, 4, or 5 hours don’t get their shoes for free, and don’t collect big checks at the finish line. They have been more cautious in their purchase selections, though it does seem that many runners are wearing the AFT shoes (Advanced Footwear Technology) these days.
Newer research has expanded to investigate if AFT shoes can reduce injury--a benefit, if proven, that would make the shoes more cost-effective for everyone.
The latest paper offers a cautious Yes to the big, important injury question. It’s a tentative first step because the report didn’t actually measure injury incidence. Rather, it looked at “cumulative tibial damage” of 19 recreational runners (8 female) who ran in both TARS (Technologically Advance Running Shoes) vs CRS (Conventional Running Shoes).
Subjects ran on a force-measuring treadmill in the lab at their previously determined lactate threshold pace--ie, reasonably close to their half-marathon running pace.
Result: Total cumulative tibial damage per kilometer was 12% lower in TARS compared to CRS. Some previous studies have shown that high tibial loading is linked to injuries like tibial stress fractures.
In addition, subjects used 3% less oxygen in TARS vs CRS. This improvement in running economy was slightly less than seen in trials with faster runners. Subjects also had lower heart rate and Relative Perceived Exertion in the TARS.
The researchers hypothesized that the more efficient running in TARS came from lower power requirements in and around the ankle. There was no difference in knee biomechanics between the two shoes. (The shoes used were the Adidas Adizero Adios 5, a conventional shoe, and the Nike Air Zoom Alphafly 1, a super shoe.)
Conclusion: “Our results suggest that running with TARS reduces oxygen cost in recreational female and male runners, which may partly be explained by differences in lower limb joint mechanics. The lower cumulative tibial bone load with TARS may allow runners to run longer distances in this type of shoe compared to CRS.” More at Nature Scientific Reports with free full text.
Recovery Science--The New Key To Optimal Fitness
Recovery is the big new star of the training-effectiveness puzzle. A training program is no longer just a matter of your total miles, or your pace/zones, or the amount of cross training you do.
It’s also about how you recover from these workouts. Otherwise, you might be training very hard without getting all the benefits you want.
A new review of “Recovery Strategies in Endurance Runners” claims to be the first to focus specifically on recovery for endurance athletes. It takes a wide-ranging view of such strategies to determine which are most useful.
The paper looked at 10 important outcomes from 22 previous papers that included more than 1100 endurance-trained subjects. The outcomes included: oxygen consumption, running economy, heart rate, lactate accumulation, perceived exertion, and muscle soreness.
The most frequently researched recovery methods were nutritional supplements and compression garments. Here are some of the key outcomes.
Nutritional supplements produced mixed results. Carbohydrate consumption and curcumin supplements appeared to benefit recovery, and pomegranate had a “potentially beneficial effect on endurance and strength.”
Compression garments generally had a positive effect on recovery, as did a variety of cryotherapy (cold) treatments. The effect of massage was marginal or nonexistent, but muscle soreness was reduced with compression garments and cryotherapy.
Conclusion: No single recovery strategy “demonstrated consistent benefits for endurance athletes in general.” On the other hand, both compression garments and cold-water immersion seemed to be promising strategies.” More at Sports Medicine Open with free full text.
How Marathon Mindset Powers Big Endurance Results
We marathon runners are a mixed bag. We come in all sizes, shapes, sexes, and performance levels.
And each of these potentially affects our perspective or personality toward the marathon. These differences were recently examined in a narrative review titled: “Personality of marathon runners: a narrative review of recent findings.”
As a general class, marathon runners exhibit a hardy personality with a strong sense of vigor. They have high levels of self sufficiency and self-efficacy--qualities often linked to good mental health. And they score low in negative traits like anger, anxiety, tension, depression, and confusion.
Women runners seem to have more “abnormal eating attitudes” than males but mostly without signs of anorexia nervosa. The women also scored high in task orientation and achieving personal goals.
Younger runners were unsurprisingly more competitive than older runners. Older marathoners placed more value on socialization, general health, and life meaning.
Higher performing or elite athletes exhibited more mental toughness, and less dissociative coping during races. They focused inward and maintained mental toughness and higher pain tolerance. They had more emotional intelligence, and perceived less stress when racing.
Conclusion: Marathon runners have a distinct psychological profile “characterized by a strong sense of vigor, self sufficiency, intelligence and introversion, and by low scores of anger, fatigue, tension, and depression.” More at Experimental & Clinical Sciences J with free full text.
CBD Doesn’t Improve Mood In 10K. But RUNNING Itself Does
Running and other endurance aerobic activities are unquestionably good for one’s health. Everyone knows this, but not everyone exercises. One reason: Some report that exercise is just too damn unpleasant.
So it’s logical to ask: Could cannabidiol (CBD, the non psychoactive component of marijuana), increase the pleasure factor of running? Could it, thereby, help get more people moving and improve the public health?
CBD is not responsible for causing a “high.” At the same time, it has been shown to reduce pain, anxiety, and inflammation for some.
In this study, Australian researchers used a randomized, controlled trial of CBD to see how it affected runners during a self-paced (ie, normal) outdoor 10K on the track. The subjects were 51 sports nutrition students at the university, including 22 females.
All runners received capsules containing 150 mg of CBD or a placebo 90 minutes before their runs. They were asked to assess their condition after laps 6, 12, 18, 24, and the 10K completion. Thus the experiment measured subjects’ experience during the run, and not just after.
The investigators hypothesized that “CBD would enhance the subjective experience of exercise.” They were wrong.
Result: There was no difference in the CBD vs the placebo condition for any outcomes, including positive and negative affect, “feeling good vs feeling bad,” exercise enjoyment, euphoria, pain, anxiety, motivation and self-efficacy, perceived exertion, or run time.
Conclusion: “CBD, taken at the relatively low oral dose of 150 mg, does not appear to enhance the subjective experience of self paced endurance exercise in recreationally active individuals. Nor, however, does it appear to compromise it.”
The paper revealed an additional significant outcome. While the CBD alone had no measurable impact on subjects, the run itself did.
Subjects reported that running 10K produced some pain and negative affect while they were at it. Let’s not mince words here: Running can be hard work.
Nonetheless, after completing the 10K, they judged that they felt “decreased negative affect and anxiety.” Thus, “This study elegantly demonstrates the powerful mood enhancing effects of exercise.”
This of course is why so many of us report that we’ve had few runs that didn’t make us feel better afterward. More at Sports Medicine Open with free full text.
Achilles Pain? There’s A Shoe For That
Some injuries resolve quicker than others, and sometimes smart shoe selection can assist the process.
I wouldn’t put Achilles tendinitis in the “short and simple” recovery bucket. But I would say that proper shoe selection can help.
That’s what “Running Physio” Tom Goom thinks as well. In fact, he’s created a neat little infographic to guide your shoe choice when your Achilles are barking.
His suggestions: Find shoes with a cushioned heel cup, a large heel-to-toe drop, and a rocker-style forefoot. Stay away from minimalist shoes. More at Twitter/Tom Goom.
A few other pointers: Switch to cross training on a bike or in the pool. When you return to running, run super-slow at first, and stick to the flats. (No hills!). In fact, the local running track is the safest place to train during your comeback from Achilles tendinitis.
The Surprising Link Between Running & A Healthier Microbiome
I remember clearly the day several decades ago when a well known endurance expert told me the future of exercise research would come from something called “the microbiome.” I had never heard the word before. That’s why I remember his comment.
Nowadays, we read something new about the microbiome almost every morning. We’re just not sure what to make of all the findings. That’s what happens when something contains “over 100 trillion microorganisms.”
Heck, we’ve only got two legs, and yet some aspects of running remain hard to understand. Like, for example, how running affects your microbiome. That’s the subject of his new paper.
It looked for differences in “gut microbiota” between “middle age serious runners” (logging more than 25 miles/week) and healthy control subjects. The two groups had similar diets, which should have resulted in similar microbiome patterns. But no.
Result: “The composition of gut microbiota in the runner groups was distinct from that in the control group.” The runners exhibited more microbiome diversity, which “may benefit host health,” according to previous microbiome-diversity research.
Conclusion: This diversity “can enhance exercise performance by promoting carbohydrate metabolism and energy metabolism related to the energy required for exercise.” Also, while scientists don’t yet understand the cause-effect pathways, “it is undeniable that a healthy gut microbiome environment contributes to maintaining the host’s healthy physiological metabolism.” More at Frontiers in Physiology with free full text.
Exercise Snacks--The 5-Minute (Or Less) Health Fix
This article was rated one of the “5 best of 2023” by editors of journals published by the American College of Sports Medicine. It appeared in Medicine & Science in Sports & Exercise. Its title: “Breaking Up Prolonged Sitting to Improve Cardiometabolic Risk: Dose–Response Analysis of a Randomized Crossover Trial.” with free full text.
The article deals with the subject of “exercise snacks,” although it did not use that term. An “exercise snack” is a short activity that you perform to interrupt a long stretch of mostly sitting, whether at work or at home (watching TV, perhaps). Prolonged sitting is bad, because “sedentary time is ubiquitous in developed nations, and is associated with deleterious health outcomes.”
While you probably can’t get up from your office chair once an hour to run 5K, you can sneak in short bursts of activity to stimulate your muscles, and burn calories. The question is: How much activity do you need to stop the “deleterious” effect of sitting?
When it comes to longer exercise periods, we’ve had helpful guidelines for decades. Aim for 150 minutes a week of moderate aerobic activity. For example, you could do 5 walks of 30-minutes each per week. (Then add several strength training sessions.) This 150-minute figure is familiar to many.
But we haven’t previously had guidance for “exercise snacks” as opposed to “exercise sessions.” Now we do.
Researchers found the answer by designing a small randomized controlled trial in which subjects (middle-age, and older) sat in a chair for 8 hours, but with breaks every 30 minutes or 60 minutes. The breaks lasted 1 minute, or 5 minutes, and consisted of “light-intensity walking.”
To gauge how these “snacks” affected subjects, researchers measured their glucose and blood pressure several times per hour.
Result: The best results were obtained when subjects took a 5-minute walk every 30 minutes. Both their glucose and their blood pressure dropped significantly. If you wait 60- minutes between “snacks,” the results aren’t as good.
Conclusion: “Higher frequency and longer duration breaks (every 30 min, for 5 min) should be considered when targeting glycemic responses.” Note: Since physiologists accept that every minute of high intensity exercise is worth two of low intensity, you could get by with just 2.5 minutes of high-intensity effort. This might include climbing stairs, doing pushups, and the like.
SHORT STUFF You Don’t Want To Miss
GREAT QUOTES Make Great Training Partners
“Before I was a master, I was a slave.”
--Ignacy Jan Paderewski, Polish pianist and eventual Prime Minister