The potency of interval training is nothing new. Many athletes have been straining through interval sessions once or twice a week along with their regular workout for years. But what researchers have been looking at recently is whether humans can increase endurance with only a few minutes of strenuous exercise, instead of hours? Could it be that most of us are spending more time than we need to trying to get fit?
“There was a time when the scientific literature suggested that the only way to achieve endurance was through endurance-type activities,†such as long runs or bike rides or, perhaps, six-hour swims, says Martin Gibala, PhD, chairman of the Department of Kinesiology at McMaster University in Ontario, Canada. But ongoing research from Gibala’s lab is turning that idea on its head. In one of the group’s recent studies, Gibala and his colleagues had a group of college students, who were healthy but not athletes, ride a stationary bike at a sustainable pace for between 90 and 120 minutes.
Another set of students grunted through a series of short, strenuous intervals: 20 to 30 seconds of cycling at the highest intensity the riders could stand. After resting for four minutes, the students pedaled hard again for another 20 to 30 seconds, repeating the cycle four to six times (depending on how much each person could stand), “for a total of two to three minutes of very intense exercise per training session,†Gibala says.
Each of the two groups exercised three times a week. After two weeks, both groups showed almost identical increases in their endurance (as measured in a stationary bicycle time trial), even though the one group had exercised for six to nine minutes per week, and the other about five hours. Additionally, molecular changes that signal increased fitness were evident equally in both groups.
There’s a catch, though. Those six minutes, if they’re to be effective, must hurt. “We describe it as an ‘all-out’ effort,†Gibala says. You’ll be straying “well out of your comfort zone.â€
http://well.blogs.nytimes.com/2009/06/24/can-you-get-fit-in-six-minutes-a-week/
