HAMILTON, ON--Just six minutes of intense exercise a week could be as effective as an hour of daily moderate activity suggests new research, although due to sprint training’s intense nature, most laypeople don’t have the discipline to keep it up.

“Sprint training may offer an option for individuals who cite lack of time as a major impediment to fitness and conditioning,” said Martin Gibala, an associate professor in the department of kinesiology at McMaster University. “This type of training is very demanding and requires a high level of motivation; however, less frequent, higher intensity exercise can indeed lead to improvements in health and fitness."

The research, which is published in the June edition of the Journal of Applied Physiology, found that performing repeated bouts of high-intensity, sprint-type exercise resulted in profound changes in skeletal muscle and endurance capacity, similar to training that requires hours of exercise each week.

The study was conducted on 16 subjects: eight who performed a two-week sprint-interval training program and eight who did no exercise training (see photo: A participant in a sprint interval training program bicycles while researchers measure his breathing rate). The training program consisted of between four and seven 30-second bursts of "all out" cycling followed by four minutes of recovery three times a week for two weeks. Researchers found that endurance capacity in the sprint group increased on average from 26 minutes to 51 minutes, whereas the control group showed no change. The muscles of the trained group also showed a significant increase in citrate synthase, an enzyme that is indicative of the tissue's ability to utilize oxygen.