Article from Runnersworld.com ©Runnersworld.com
In a new study out of McMaster University in Hamilton, Ontario, researchers have found that completing 20-minute sessions of cycling intervals–with one minute at 90 percent maximum heart rate, one minute rest, repeated 10 times–significantly boosts overall health and fitness, even in patients with cardiovascular disease.
It might seem counterintuitive that strenuous exercise would be productive or even wise for cardiac patients. But so far none have experienced heart problems related to the workouts, [lead researcher Dr. Maureen] MacDonald said. “It appears that the heart is insulated from the intensity” of the intervals, she said, “because the effort is so brief.”
Almost as surprising, the cardiac patients have embraced the routine. Although their ratings of perceived exertion, or sense of the discomfort of each individual interval, are high and probably accurate, averaging a 7 or higher on a 10-point scale, they report enjoying the entire sessions more than longer, continuous moderate exercise, Dr. MacDonald said.
“The hard work is short,” she points out, “so it’s tolerable.” Members of a separate, exercise control group at the rehab center, assigned to complete standard 30-minute moderate-intensity workout sessions, have been watching wistfully as the interval trainers leave the lab before them. “They want to switch groups,” she said.
The American Heart Association recommends 30 minutes of continuous, moderate exercise five times a week, but this study indicates that 20 minutes of interval training is as beneficial and possibly more enjoyable. And, obviously, the interval workouts are shorter. The majority of Americans who don’t exercise say it’s because they don’t have time.
If you’re in the minority–that is, you do have time for prolonged, moderate exercise–you shouldn’t abandon your current regimen. This type of exercise also has proven heath benefits. But on days when you’ve got to squeeze in a workout, intervals may be the way to go.