Tuesday, August 04, 2015

New stuff on exercise, brain, and body.

I'll use this post to point readers to several recent interesting articles on physical activity. Hutchinson does a review of work that distinguishes the effect of strength and endurance training versus balance and stability training. The former isn't all that useful without the later, especially in older adults (have you tried standing on one leg with your eyes closed lately?). A German study followed aged adults for 12 months comparing those who did cardiovascular (walking) exercise three times a week, with those who did coordination training. Both groups showed improvement in cognitive functioning, but in different ways. Cardiovascular training was associated with an increased activation of the sensorimotor network, whereas coordination training was associated with increased activation in the visual–spatial network. Mouse studies show that aerobic exercise and strength training trigger brain chemicals that enhance neuron growth and survival, while balance and coordination exercises also recruit higher-level cognitive processes that seem to increase the number of synapses connecting neurons. Work by Kumpulainen et. al. suggests that novelty and unpredictability (as in gymnasts or dancers), rather than repetition (as in endurance athletes), are essential in brain plasticity and engagement.

In another item, Reynolds updates the story on the beneficial effects of intense interval training. Just a few minutes of very intense exercise are much more effective in improving health and cardiovascular fitness than slow and steady repetitive exercise. To try to deal with the problem that most people really don't enjoy zonking themselves out with intense intervals, Bangsbo and collaborators tried a different approach, asking runners to run gently for 30 seconds, then accelerate to a moderate pace for 20 seconds, then sprint as hard as possible for 10 seconds. Repeat five times, rest for a bit, and continue the sequence during a 5-km run. They observed the same beneficial effects on blood pressure and endurance observed with more arduous (several minute) bouts of high intensity training. I tried this 30-20-10 sequence with my favored aerobic exercise, swimming (just counting the intervals to myself made them pass more quickly), and I came out of the routine feeling way more wired than after my usual moderately active swim period.

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