Researchers at McMaster University have found that a single minute of very intense exercise produces health benefits similar to longer, traditional endurance training. The findings put to rest the common excuse for not getting in shape: there is not enough time.
"This is a very time-efficient workout strategy," says lead author on the study. "Brief bursts of intense exercise are remarkably effective."
Scientists set out to determine how sprint interval training (SIT) compared to moderate-intensity continuous training (MICT), as recommended in public health guidelines. They examined key health indicators including cardiorespiratory fitness and insulin sensitivity, a measure of how the body regulates blood sugar.
A total of 27 sedentary men were recruited and assigned to perform three weekly sessions of either intense or moderate training for 12 weeks, or to a control group that did not exercise).
The McMaster team has previously shown that the SIT protocol, which involved three 20-second 'all-out' cycle sprints, was effective for boosting fitness. The workout totaled just 10 minutes, including a 2-minute warm-up and 3-minute cool down, and two minutes of easy cycling for recovery between the hard sprints.
The new study compared the SIT protocol with a group who performed 45 minutes of continuous cycling at a moderate pace, plus the same warm-up and cool down. After 12 weeks of training, the results were remarkably similar, even though the MICT protocol involved five times as much exercise and a five-fold greater time commitment.
"Most people cite 'lack of time' as the main reason for not being active", according to the author. "Our study shows that an interval-based approach can be more efficient -- you can get health and fitness benefits comparable to the traditional approach, in less time."
"The basic principles apply to many forms of exercise," author says. "Climbing a few flights of stairs on your lunch hour can provide a quick and effective workout. The health benefits are significant." The findings are published online in the journalPLOS ONE.