The consensus public health recommendations on physical activity that emerged in the mid-1990s from the Centers for Disease Control and Prevention, the American College of Sports Medicine, and the U.S. Surgeon General's report recommended that people accumulate at least 30 minutes of moderate intensity activity on most days of the week.
“'Most' means 5 days, so 30 minutes of walking 5 days a week,” Dr. Blair said. “ 'Accumulate' means you don't have to go for a 30-minute walk. You can go for two 15-minute walks or three 10-minute walks, or four 8-minute walks.”