Newsletter #225

Tons of research has shown that physical activity, in general, is linked to improvements in mood and cognitive performance. However, the mental payoff can be quite different depending on your exercise of choice. You’ve probably read, for instance, that high-intensity training elicits unique benefits for brain performance, compared to easy activity.

But what about the context in which exercise is performed, and the types of movements that you’re doing?

We have known for some time that lab animals that exercise in an “enriched” environment - meaning one where they have to confront new surroundings, deal with unpredictable situations, and solve problems - experience greater improvements in cognition than they get from either exercise or enrichment by itself.

Does this also apply to humans? Well, research comparing open skill versus closed skill exercise makes a pretty compelling case. Basically, closed skills occur in a predictable and static environment, where the activity is repetitious. Think walking, jogging, swimming, stuff like that. On the other hand, open skills involve a dynamic, unpredictable environment where you are responding to all kinds of stimuli, like in team sports, martial arts, etc. Obviously, the latter involves very different physical demands than the former. But it also pushes you more mentally. Think about what your brain has to juggle in order to score a goal in soccer, versus jogging on a treadmill. In particular, open skill exercise taxes your higher order cognitive processes - executive functions - more than closed skill activity. And this cognitive load may influence the long-term cognitive benefits that you get from that type of activity, which of course helps you in every aspect of daily life - not just sports.

Researchers in New York recruited 10 middle-aged participants who were enrolled at a martial arts school. All participants were in good health and had attained the rank of black belt. The subjects took part in separate 1-hour long exercise conditions, in which they either participated in a martial arts class (open skill) or brisk walking (closed skill). Before and after each exercise session, they were administered a cognitive test. As you might expect, both walking and martial arts led to better attention and processing speed, with large effect sizes. However, only the martial arts training improved executive function. The researchers attribute this difference to the increased cortical recruitment needed to meet the complex motor demands of martial arts, compared to the more repetitive actions of walking, which in turn may lead to greater blood flow to the areas of the brain involved with executive function.

Task-switching is an executive function that involves the ability to unconsciously shift attention between one task and another. Notably, badminton resulted in a significantly greater boost in serum levels of brain-derived neurotrophic factor (BDNF) compared to running.

BDNF is a growth factor that is involved in learning and memory (sometimes referred to as "fertilizer for your brain"). When the participants played badminton, they also experienced a reduction in task-switching cost. Normally, when you are forced to switch from one task to another, your performance in these tasks suffers (refer to this podcast for more info). So, the open skill exercise seemed to make it easier for these subjects to switch their focus between different activities, which is obviously helpful for productivity at work, school, and all kinds of other important stuff in life.

Researchers in Turkey recruited 18 fencers (open skill) and 18 swimmers (closed skill) from national sport clubs, as well as a control group of 18 sedentary individuals who weren't involved in any kind of sport. All participants visited the lab for baseline blood work as well as a battery of cognitive tests. They returned 48 hours later to perform 40 minutes of running on a treadmill, followed by another round of testing. After the exercise bout, all of the athletes showed higher scores on some of the cognitive functions. However, the fencers performed better on certain tasks (visuospatial working memory, verbal fluency, selective attention). The fencers also showed higher levels of Cathepsin B at baseline and experienced a much greater boost in this protein in response to the exercise. Cathepsin B is a factor secreted by muscles in response to exercise, much like BDNF, and which has been shown to be associated with memory in humans.

Of course, many aspects of sports nutrition are the same for both men and women, and plenty of people have done well just applying the same general guidelines across both genders. However, there are a few noteworthy differences, and better understanding of these unique considerations can lead to improved training and greater success in competition.

In this course, we cover female hormones, optimizing energy intake, specific micronutrients that are often a concern for female athletes, how to maintain optimal hydration, how to plan training at different points in the cycle, and how to avoid health issues associated with inadequate energy availability (female athlete triad). If you are a woman who trains regularly, or if you coach women/girls, this course should prove to be a useful resource for you.

Thanks for reading, enjoy the weekend, and we'll see y'all next week!

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