From Harvard Magazine:
For patients with high blood pressure, doctors are likely to prescribe antihypertensive medication and provide detailed instructions about how much to take, and when. They have been less able to provide detailed dosage recommendations for exercise. Research shows that a regular walking, swimming, or tennis habit reduces chronic disease risk, but it’s been unclear just how much different levels of exercise might extend our lives. Now, a study coauthored by epidemiologist I-Min Lee, a professor of medicine at Harvard Medical School and professor of epidemiology at Harvard School of Public Health, offers specific exercise prescriptions. Lee and her colleagues pooled data from six large studies that included information on the leisure activities and body mass index of more than 650,000 people older than 40, each of whom was followed for an average of 10 years. The researchers’ analysis revealed that subjects who completed the equivalent of 75 minutes of brisk walking each week—roughly 11 minutes a day—lived 1.8 years longer than those who didn’t exercise at all. Those who got the federally recommended minimum of 150 minutes of moderate-intensity exercise a week—22 minutes every day, or 30 minutes a day, five days a week—gained 3.4 years.
Lee was somewhat surprised that even small amounts of movement made such a difference. “What we found is really encouraging,” she says. “If you do a little, you get a fairly good gain in years.”