Were they reaping any benefits from a ratcheted-down, moderate workout routine?
"Sure they're getting benefits, but in general, more is better," says Joe Miller, MD, a preventive cardiologist at Emory University School of Medicine. He agreed to discuss the findings with WebMD.
In fact, 25 minutes a day is the minimum anyone should get for heart protection, Miller says. "Most data indicates that people do better if they get moderate, sustained exercise like moderate-intensity walking for 25 minutes, four to five times week."
He encourages people to make little changes in their daily routine -- walk between terminals at the airport, park the car at the far end of a parking lot, that kind of thing. Exercise accumulated during the day can equal a moderate workout routine, Miller says.
But if you're trying to lose weight, aim higher -- make moderate workout routines longer than 20 minutes a day, says Andrew Sherman, MD, a physiatrist at the University of Miami School of Medicine.
"Obviously, some exercise is better than no exercise," Sherman tells WebMD. "But if you're ever going to get significant fat-burning benefits from aerobic exercise, the magic number is more than 20 minutes per session."
In the first 20 minutes, your body burns carbohydrates; after that, you begin burning more fat than carbohydrates, Sherman explains. "By exercising for a too-little period of time, you may get some benefits from not being totally sedentary, but you're not necessarily going to gain any fat-burning potential."
"We all would like exercise in pill," Miller tells WebMD. "The American mentality is to get more for less. It's the American dream. But when it comes to preventing heart disease, hypertension, diabetes, it just doesn't work that way." A moderate workout routine -- over the long haul -- can keep fat and disease at bay.