October 27, 2022

New fueling strategy: Carbo-load first, then have one high-fat meal

Runners and researchers have spent a lot of effort in the last 20 years looking for ways to maximize endurance performance by manipulating diet in the hours and days before a big race. The goal? To arrive at a point where the body burns optimal amounts of fat and carbohydrate. 


One approach that has been tried: Get keto-adapted with a high-fat diet, then switch to carbs for several days pre-event. That generally didn’t produce good results. A new paper proposes the opposite strategy: Carbo-load first, then consume fat for your last meal before racing. 


This seemed to work, with the researchers noting that “One high-fat meal following carbohydrate loading reduced muscle and liver glycogen use during the 60-minute exercise.” Conclusion: “This dietary approach may be applied as a strategy to optimize energy utilization during endurance exercise.” More at J of Strength & Conditioning Research.


Strava “kudos” have unexpected impact

In running you can compare yourself to yourself, or to the hordes on social media and elsewhere, particularly those on fitness tracking apps like Strava. In the former case, you likely keep tabs of your personal records. At a certain age, this becomes a losing battle. That’s why one of my running friends notes his PRs after each birthday. Every year, he sets multiple new bests. Smart. 


Another way to do this: Reset your GPS watch. That’s what Sabrina Little did, and she’s a 5-time U.S. champion (trails and ultras), and PhD in philosophy, and columnist at “IRunFar.com,” and forthcoming book author did after her pregnancy. Not exactly a low achiever.


My watch just congratulated me for a 2.5-mile walk as my longest endurance effort ever. Hahaha.” she writes on Twitter. I like it.


Strava seems to be the undisputed leader in global fitness tracking, and pretty much everyone gets psyched up and motivated by the “kudos” they receive from followers. These can certainly provide a boost to your training.


But when big-data researchers dug into the overall back-and-forth flow of kudos on Strava (among members of Dutch running clubs), they reached a surprisingly different conclusion. “Athletes on Strava were mainly negatively influenced by the activity levels” of followers. 


What in the world? How do you explain this? “Our friends who run less often show it is okay to do less and may justify deviation from our goals.”


They add a telling note about “web scraping” Strava data, as they did. “Since the time of our data collection, Strava has blocked multiple endpoints of their API and updated their robot exclusion protocols. We also observe that at the time of writing (2022), far more athletes have set their activities to private than when we collected our data (2019).” More at Social Networks.


Marathon drinks better with more salt 

Everywhere I look, I find runners who think more sodium is the path to better marathon running. One of these is my wife. She was having terrible GI issues in the 2010 Marathon to Athens race celebrating the 2500th anniversary of Pheidippides legendary run until a “marathon angel” came along and offered her salt (from a shaker). Problem solved.


Others believe sodium can improve performance, decrease the effects of heat, lessen the risk of hyponatremia, and more. Research is not always supportive. However, a new paper is.


The investigators chose endurance trained males to complete 3-hour laboratory bike rides at 93 degrees F with a standard sports drink and another one that contained 3x as much sodium. Subjects crossed over and performed with both drinks. While consuming the salty drink, they showed “improved plasma volume and sodium maintenance.” Conclusion: The outcome “supports the body of knowledge indicating that sodium has a clear role in the maintenance and reinstatement of fluid and sodium balance with long lasting, moderate intensity exercise in the heat.” More at Europ J of Applied Physiology.


Should you PIMP your stride to avoid injuries?

A group of mostly French and Swiss researchers has proposed a method of looking at typical running styles, classifying them, and then suggesting exercises that will limit injuries. I’m not sure I can explain this correctly in a short space, but here goes.


The Voldalen approach divides runners into those who mostly shuffle and those who bounce more. That’s fine. They don’t care which you are, as they say the two are equivalent in terms of injury incidence. The key is to make the best of what you are naturally.


To do this, they suggest that shufflers should mainly focus on stretchy-extension type exercises, and bouncers on exercises that improve leg strength and stiffness. These should give you more of the body mechanics demanded by your preferred movement pattern (ie, your stride). More at Frontiers in Rehabilitation Science.


Inspiratory muscle training extends respiratory endurance

Inspiratory muscle training continues to look good in recent research studies. In one 6-week training study, it proved successful at “lowering resting blood pressure and improving inspiratory muscle strength.” Thus it “extended the capacity for respiratory work and endurance in healthy, recreationally-active young adults. The outcomes have implications for athletic conditioning and for attaining and maintaining cardiorespiratory fitness.”


Another research project looked into the effect of a brief warmup with increased inspiratory muscle breathing on runner performance during 30 second sprints. The breath work was “effective in increasing the peak and mean relative running power.” The investigators “recommend this respiratory strategy to improve exercise and recovery.” More at Biology.


Carbon plates mainly benefit faster runners

The above-reviewed shoes have some form of a stiff plate running through the midsole along with a new super-foam as the main midsole material. So which of the two is providing the “super” burst of speed and endurance? Good question.


A number of top running biomechanists have hypothesized that most or all of the benefit comes from the new generation of super-foams rather than from the stiff plates. In this new paper, researchers specifically investigated how shoe-stiffness (from carbon plates) affected running economy in a varied group of runners.


Conclusion: Those rated “high level” runners [which I presume to mean “faster”] gained some benefit from running in stiff shoes. “Whereas medium-level runners did not.” Roughly one-third of all runner-subjects actually exhibited worse running economy in stiffer shoes. 


What does all this mean? First, to bend a stiff carbon plate and gain some energy return, you have to hit the ground hard. That’s what faster runners do vs slower runners. Second, and central to all shoe-runner interactions: “This study emphasizes the importance of individual response examination to understand the effect of footwear on runner's performance.” More at European J of Applied Physiology.


Menthol “facilitates breathing comfort” during hard exercise

In the last year, several research reports have concluded that menthol-products can improve endurance performance. Of course, not all research trials have produced similar results. Here’s one that didn’t.


The most recent menthol paper looked at both ease of breathing and time-trial performance. It found that ingestion of a menthol drink “facilitates breathing comfort during exhaustive endurance running,” and also “improves running capacity in well-trained runners.” The subjects were all runners with a half-marathon personal best under 1:20. That’s a nice plus for this study. More at European J of Sport Science.cus


Best lifestyle approaches to depression

As mental health becomes a larger and larger social concern across the country and globe, we try to learn more about underlying factors and possible action steps. Taking a wide view of running, I’d say we’ve largely agreed that it can be helpful but definitely not a guaranteed preventative. It’s like heart disease: Running is great, but there are other powerful factors as well.


Here’s a wonderful and looong (54 pages, free full-text) “Clinical Guidelines” review from several professional groups. When it comes to lifestyle therapies (as opposed to meds), it finds that the “recommendations with the highest rating” against Major Depressive Disease are: exercise, relaxation techniques, work directed interventions, sleep, and mindfulness therapies. “Interventions related to diet and green space were recommended, but with a lower strength of evidence.” More at The World Journal of Biological Psychiatry.


With knees, “Use it or lose it” seems good advice

If only the general public understood what their Health Care Providers know to be true--that exercise, and specifically running, can be generally beneficial for those with knee arthritis. In a large survey, the public ranked exercise/running far worse for knee arthritis than HCPs did. In fact, “The majority of HCPs reported being relatively confident in providing evidence-based recommendations about running and knee health.”


In another paper, the authors support “Benefits and Mechanisms of Exercise Training for Knee Osteoarthritis.” because “Increasing evidence indicates that exercise training can improve pain, stiffness, joint dysfunction, and muscle weakness in patients with knee osteoarthritis.” In general,  low-intensity aerobic exercise are better for patients with severe KOA,” but there are instances where high-intensity workouts can provide greater payoff. More at Frontiers in Physiology.


Olympic Committee offers new guide to respiratory infections 

The Olympic Games bring together the world’s best athletes and perhaps the world’s greatest swirling collection of germs and viruses (roughly 20,000 individuals from 200 countries in tight quarters and shared cafeterias). The result is a lot of “colds” which a new 2-part IOC consensus statement terms “ARinfs.” That stands for “acute respiratory infections” in athletes.


The second part of this two-part paper is the most useful to coaches and athletes, as it digs into key training question, “How much is too much?” question. It includes guidelines for “prescription of training and competition load, as well as for monitoring of training, competition and psychological load, athlete well-being and illness. In the process, urgent research priorities were identified.” More (free, full text) from Brit J of Sports Medicine, Part 1 and Part 2.


So you think you know bread?

Forty years ago I knew high mileage runners who bragged about eating a loaf of bread a day. Now, that happens less often, as more people are concerned about processed carbs. We’ve become more educated about bread. (Does anyone still eat Wonder Bread?)


I figured I’d totally ace this True/False quiz from WebMD, but I was surprised to get several wrong. You might learn how “enriched” bread is deceptive, and how pumpernickel scores important health points. When you’re done, you’re certainly allowed to eat a little bread every day, especially if contains lots of fiber. Just keep it under control. More at WebMD.


SHORT STUFF  you don’t want to miss

>>> For increased strength, “get to the gym, and get their regularly,” says expert Stu Phillips. Don’t worry about protein.

>>> If you have Type 1 diabetes, running provides better blood glucose control than cycling.

>>> Mom’s consumption of ultra processed foods during pregnancy and child-rearing raises child’s risk of overweight/obesity.


GREAT QUOTES make great training partners

"It does not matter how slowly you go so long as you do not stop."

--Confucius