As little as two minutes of high-intensity exercise four times a day improves health outcomes in adolescents, but the same amount of moderate-intensity exercise does not reap the same rewards, according to a new study from the University of Exeter.
Researchers found that when exercise is broken up into short bursts over the course of a day - replicating the way young children go about being active - only high-intensity exercise is effective in improving blood sugar levels, fat metabolism and blood pressure in adolescents after the consumption of a fatty meal.
The research, published in the journal Metabolism: Clinical and Experimental, adds to the growing body of literature suggesting that accumulating short bouts of high-intensity exercise may be more important for cardiovascular health than exercising at a moderate intensity. This is important, as cardiovascular diseases are the leading cause of death in the UK and the process underlying these diseases starts in youth.
Dr Alan Barker, of the Children's Health and Exercise Research Centre, Sport and Health Sciences at the University of Exeter, said: "Children and adolescents tend to perform brief bouts of exercise. This study shows that the intensity of this pattern of exercise is important, with high-intensity providing superior health benefits than moderate-intensity exercise".
In the study, adolescents had their blood sugar, blood pressure and fat metabolism measured at regular intervals over 8 hours, which included the consumption of a fatty meal for breakfast and lunch. During this period the participants were asked to perform four bouts of high- or moderate- intensity exercise. The participant performed the same amount of work during the high and moderate- intensity exercise bouts. This allowed the researchers to conclude that the intensity of exercise is important for health in adolescents when the exercise is accumulated during the day.
'Accumulating exercise and postprandial health in adolescents' by Bert Bond, Craig A. Williams, Sarah R. Jackman, Adam Woodward, Neil Armstrong and Alan R. Barker is published in the journal Metabolism: Clinical and Experimental.