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Newsletter #121: Stress Is Challenging - But Exercise May Help Keep Your Body and Mind Strong 💪🏽
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! Below, as always, is a roundup of the various studies and other media that we came across. 🤓
This week, we learned that regular aerobic exercise is really helpful for depression (perhaps on par with pharmaceutical interventions), but your brain’s reward processing may influence whether or not you respond to it. We also learned that both high- and moderate-intensity exercise boost levels of BDNF, which is accompanied with greater brain power. Finally, the largest study of accelerometer-measured physical activity ever revealed that exercise at any intensity is associated with reduced risk of death (duh), but performing the same volume of activity at a higher intensity confers additional longevity benefits.
Scroll down to learn more, and stay safe everyone. 👇
This Week’s Research Highlights
🏋 Any physical activity is beneficial for health - but more intense exercise is better.
Researchers analyzed data from 96476 participants in the UK Biobank study who wore a research-grade activity tracker on their dominant wrist for a week. The scientists were able to capture the duration and intensity of movement and used this information to calculate the total volume of activity, expressed as physical activity energy expenditure (PAEE). Expending more energy at any given intensity was associated with a lower risk of all-cause mortality. For instance, subjects who accumulated 20 kJ/kg/day were about a third less likely to die, compared to those who achieved 15 kJ/kg/day, and those who accumulated 30 kJ/kg/day were about half as likely to die in the follow-up period, assuming that about 10% of the total activity was moderate intensity. However, more high-intensity activity seemed to confer substantially greater benefits. For instance, if the volume of 30 kJ/kg/day included 30% from at least moderate intensity activity, rather than 10%, then subjects were only about a quarter as likely to die.
🧠 Both high- and moderate-intensity exercise can boost growth factors in the brain and improve cognition.
Twenty obese men were randomized to either moderate-intensity continuous training (n = 10) or high-intensity intermittent training (n = 10) three times a week for 6 weeks. Importantly, the workouts were planned so that exercise sessions for both intensities had the same energy expenditure (~ 300 kcal). Both conditions showed significant increases in brain-derived neurotrophic factor (BDNF) immediately after acute exercise, and also showed improvements in cognitive performance.
🏃♀️ Aerobic exercise is more beneficial for depression in people with higher levels of reward processing.
Researchers recruited 66 young adults with major depression, and randomized them to either 8 weeks of moderate-intensity aerobic exercise (n = 35) or light stretching (n = 31). Depressive symptoms were assessed across the intervention to track symptom reduction, and the researchers also performed EEG to assess reward processing and cognitive control using event-related brain potentials prior to the intervention.
The exercise group experienced a ∼55% depressive symptom reduction, compared to a ∼31% reduction for the stretching group. However, not everyone benefited equally. Notably, those who exhibited greater baseline reward processing were significantly more likely to show a successful treatment response.
Podcasts We Loved This Week
- Naomi Allen: How the UK Biobank is Powering Chronic Disease Research. Via Sigma Nutrition.
- Johan Auwerx: Enjoying Youthful Vitality As We Age. Via LLAMA Podcast.
- Shelly Miller & Jose-Luis Jimenez: How Your Indoor Air Ventilation Affects Coronavirus Spread. Via Science Friday.
Products We Are Enjoying
ZENB veggie sticks.
These bars are made primarily from organic vegetables. What I like about them is they intentionally incorporate parts of the vegetable that are often discarded - stems, skins, seeds, etc. This reduces waste and also ensures that you are consuming the most nutrient-rich parts of the plant (as we discussed in this course). They are surprisingly tasty and a good pre-workout snack. The company helpfully offers trial packs, if you’d like to give them a shot.
