High-intensity exercise training is one of those things people know they should do, but usually don't. Why? Despite the fact that interval training (alternating short bouts of high and moderate exercise) strengthens the heart and improves the cardiovascular system, working at such an extreme level doesn't always feel good. Most prefer doing their cardio at a moderate level, breaking a sweat but not working too hard.
A new study in the March issue of the Journal of Physiology shows that working under maximum capacity for short bouts, interspersed with stints at a lower intensity, may produce physical improvements without having to spend hours exercising.
Researchers tested seven men, average age 21, who were recreational exercisers. Each took part in six stationary cycling training sessions in the course of two weeks that consisted of eight to 12 one-minute bouts of high-intensity exercise alternated with 75 seconds of recovery. In all, sessions lasted about 20 to 25 minutes. Over two weeks the participants did two hours and 25 minutes of exercise.
In a similar study published in the Journal of Physiology in 2006, participants exercised at maximal capacity for short bouts on specially designed stationary bikes or did more moderate cycling for much longer periods. In that study, both groups showed similar improvements in exercise performance and muscle health.
In this study, those improvements were seen again despite the fact that the high-intensity bouts were done below maximum capacity and on standard stationary bikes.
"What we've been able to show is that interval training does not have to be 'all out' in order to be effective and time-efficient," Martin Gibala, the study's senior author, said in a news release. The professor and chair of the department of kinesiology at McMaster University in Ontario, Canada, added: "While still a very demanding form of training, the exercise might be more achievable by the general public -- not just elite athletes -- and it certainly doesn't require the use of specialized laboratory equipment."
Most fitness experts recommend mixing high-intensity interval workouts with longer moderate-level endurance workouts for optimum cardiovascular training. The high-intensity workouts can be done on treadmills, elliptical trainers and other machines, or via running or cycling sprints. Group cycling classes typically alternate bouts of intense work with pedaling at more moderate rates.
-- Jeannine Stein
Photo credit: Susan Spano / Los Angeles Times