Short Bursts of Exercise Best for the Heart

All exercise is the same, right? Not so fast, suggests a small study of teens out of Scotland. They found that high-intensity exercise may be better than endurance training for preventing cardiovascular disease because it can be done in less time.

Study Details

The study included 57 adolescent schoolchildren (47 boys and 10 girls) who were randomly assigned to high-intensity or moderate-intensity exercise groups.

Both groups did three exercise sessions a week for seven weeks. The high-intensity group's program consisted of a series of 20-meter sprints over 30 seconds, while the children in the moderate-intensity group ran steadily for 20 minutes.

By the end of the seven weeks, teens in the moderate-intensity group had completed a total of 420 minutes of exercise, compared with 63 minutes for those in the high-intensity group. The estimated amount of total calories burned per child was 4.410 for those in the moderate-intensity group and 907.2 for those in the high-intensity group.

Both groups of children showed significant improvements in cardio-respiratory fitness, blood pressure, body composition and insulin resistance. But the teens in the high-intensity group achieved those health benefits with only 15% of the exercise time put in by those in the moderate-intensity group.

Implications

The findings, published in the American Journal of Human Biology, suggest that brief, intense workouts offer a time-efficient way to reduce cardiovascular disease risk factors in teens, said study author Duncan Buchan, MSc, or die University of the West of Scotland, and his colleagues.

Further research is needed to confirm the findings, they added.