Quirks and Quarks, Canada's national science radio show, ran an excllent piece this weekend on "exercise myths," talking to researchers who've concluded that stretching before exercise impairs performance, that weekend-only workouts have very small health-benefits, and that some people just don't respond to exercise. The connection to genetic research into the Type II diabetes epidemic is really fascinating, as is the evolutionary biology theories that tie both together:
First on the agenda is stretching. For decades stretching has been seen as an essential preliminary to a workout. But according to Dr. Ian Shrier of the faculty of Medicine at McGill University, and past president of the Canadian Academy of Sport Medicine, that's old, and bad, advice. Research has shown that pre-workout stretching decreases performance and doesn't protect against injury.
Dr. I-Min Lee, a professor at Harvard Medical School and the Harvard School of Public Health has studied people who pack all their exercise into one weekend binge. She discovered that if you have any risks for heart disease, being a weekend warrior is as bad as getting no exercise at all.
Most surprising is that exercise can have no effect at all on some people. Dr. Claude Bouchard, Executive Director of the Pennington Biomedical Research Center in Baton Rouge, Louisiana, discovered early in his career that there's enormous variation in how people respond to cardiovascular exercise, with some not responding at all.
