The studies that showed that three short sessions of exercise gave 60% as much benefit as one long session were touted as showing that brief, mild exercise was just as good. (Similarly, studies showing that Vitamin C reduced colds by 40% were considered not significant.) Now, a study published in Preventive Medicine emphasizes that for major health benefits, a fair amount of vigorous exericise is needed.
Traditionally, adults were encouraged to take part in 20 to 60 minutes of vigorous exercise three or more times a week. In 1990, research showed around 90% of British adults believed vigorous exercise was important in maintaining and improving health and fitness. Since 1995 the Department of Health has instead promoted 30 minutes of moderate exercise five times a week, which can be achieved through everyday activities such as walking, housework or gardening. The research team believes this shift in attitudes is threatening the nation’s health and is calling for evidence-based guidelines.
I think that the jury is still out on this. A study in NEJM of 73,000 women showed that walking and vigorous exercise had similar benefits. That’s a big study. The study in Preventive Medicine mentioned above had about 1300 participants if I recall correctly.
After all, it may have been running that made us human.