Short Intervals Equal Long Ones -- MEDICA - World Forum for Medicine

"The most striking finding from our study was the remarkably similar improvements in muscle health and performance induced by two such diverse training strategies," says Martin Gibala, an associate professor of kinesiology at McMaster University.

The "catch" is that the exercise consists of short bursts of intense effort separated by a few minutes of recovery, meaning a single training session lasts about 20 min.

Sixteen young men performed six training sessions over two weeks. Eight subjects performed between four and six 30-second bursts of "all out" cycling separated by four minutes of recovery during each training session. The other eight subjects performed 90-120 minutes of continuous moderate-intensity cycling. Total training time commitment including recovery was 2.5 hours in the sprint group, whereas the endurance group performed 10.5 hours of total exercise over two weeks. Both groups showed similar improvements in exercise performance and the muscle's ability to resist fatigue.

"Our study confirms that interval-based exercise is indeed a very time-efficient training strategy," says Gibala. "It is a demanding type of training and requires a high level of motivation, however it might be the perfect option for those who say they have no time to exercise."

For weight-conscious exercisers who are concerned that high-intensity training doesn't burn as many calories as long-duration exercise, Gibala says: "People forget that if you do a 30-second hard spurt your body continues to burn calories during recovery; just because you have physically stopped racing doesn't mean the effects of the workout are over."; Source: McMaster University