Newsletter #246

Hey friends! This week, I thought I would take a look at a couple of new trials examining the impact of different forms of exercise on cognition in children. Best of all, these exercise interventions require little to no equipment and are very efficient, meaning that they’re easy to fit into a busy schedule.

A major reason why physical activity is linked to improved brain performance is due to its metabolic effects. In general, exercise has been shown to lead to greater cortical blood flow, which in turn enhances oxygen and glucose supply to the brain. Exercise also leads to an increased release of neurotrophins, which stimulate growth of nerve cells and the formation of synapses. Perhaps most notably, aerobic exercise boosts levels of brain-derived neurotrophic factor (BDNF), which plays a key role in memory formation and learning.

But although any activity beats doing nothing, it is likely that certain forms offer unique advantages, as you’ll see below. Specifically, there is reason to believe that the intensity and the complexity of the exercise has an impact on subsequent cognitive benefits, and this appears to be the case for both kids and adults.

Short intense bouts of exercise seem to increase levels of growth factors more than prolonged moderate-intensity activity. For instance, a recent experiment showed that just 6 minutes of hard cycling intervals increased circulating BDNF 4-5 times more than 90 minutes of light cycling, suggesting that HIIT may be particularly powerful for maximizing one’s ability to store and recall information. To examine how this might translate to school-age children, researchers in England recruited sixteen girls (age 11-12) and randomly split them into two groups. One group continued their regular physical activity levels (control), and the other was assigned to two weeks of supervised sprint training before school. The training involved three 20-min sessions per week, and increased from 6 x 10 sec sprints up to 8 x 10 sec sprints. To avoid self-selecting for individuals who were already athletic, all participants were incentivized with an Amazon gift card upon completion of the study. At the end of two weeks, the sprinting group showed greater accuracy in a test of working memory, compared to controls, and serum concentrations of BDNF at follow up were more than double that of controls (42.9 ng·ml−1 versus 19.2 ng·ml−1). Pretty impressive for an intervention that required a very small time commitment.

A number of prior studies have shown that exercise with greater coordinative and cognitive demands, such as sports and martial arts, seem to produce greater improvements in learning than more monotonous activities like running on a treadmill. To examine whether different styles of jumping rope, an activity that certainly demands serious coordination, could boost academic performance in kids, researchers affiliated with the University of Mainz in Germany recruited 26 adolescents (age 13-14 years) and split them into two groups. All participants embarked on a 3-week jump rope intervention, with 9 sessions conducted during their second hour of school. At each of these sessions, participants spent 15 minutes studying mathematics, which was immediately followed by three rounds of 60 sec skipping rope, separated by 30 sec breaks. One group, the controls, were instructed to jump as consistently as possible in a steady rhythm at a constant speed (basically as monotonously as possible). The other group, referred to as the differential rope skipping group, kept switching to different jumping styles and movements every 20 seconds, for instance swinging backwards, crossing legs, etc. At the end of the study, the children in the differential rope skipping as a whole showed substantially greater improvements in their mathematical performance. In fact, every single child in the differential rope skipping group improved from baseline, while five students in the control group either stayed the same or got worse.

🫀 The fastest heart rate ever recorded in a human was about 600 beats per minute — closer to the normal resting heart rate of a mouse than a human.Clinicians reported “an extreme non-fatal tachyarrhythmia” in a hospitalized quadriplegic man, which was recorded via telemetry.

The second fastest heart rate observed in an adult, by the way, was Danish audiologist Ole Bentzen, who famously died laughing (literally) while watching the movie A Fish Called Wanda, with a heart rate between 250 and 500 beats per minute.

Meta Quest 2

Thanks, as always, for reading, and we'll see y'all next week!

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