EXETER, England, Sept. 30 (UPI) -- Teenagers who perform high-intensity exercise in bursts of eight to 10 minutes three times a week can significantly decrease the risk they will develop a heart condition, according to a small study in England.
Other recent studies have shown short bursts of exercise have similar effects on younger children, and can also help to hold off diabetes in adults.
Teenagers in England are recommended to get at least 60 minutes of exercise per day, however national health surveys show less than 30 percent of teen boys and 20 percent of girls do so.
"We know that activity levels drop significantly as children reach adolescence, and so far attempts to increase this to an hour a day have proved fruitless," said Dr. Alan Barker, a professor at the University of Exeter, in a press release. "This study indicates that, providing the intensity is high, health benefits are achievable with just 8-10 minutes of exercise."
Researchers in the study, published in Heart and Circulatory Physiology, asked six girls and seven boys between the ages of 13 and 14 to have six high-intensity workouts over two weeks. Teens were instructed to cycle one-minute bursts of exercise broken up with 75 seconds of rest. During the two weeks, the teens built from eight bursts per workout to 10, for a total of 10 to 15 minutes of exercise.
All of the teens showed improvement to blood vessel function and the ability of the brain to control heartbeats, both of which are considered markers for possible cardiovascular disorders. The researchers found, however, that most of the improvements were lost after the two weeks of exercise ended -- suggesting an exercise regimen must be maintained for the health benefits to continue.
A recent study conducted by the National Institutes of Health found similar results in younger children. Researchers in that study asked children watching television to take a three-minute break from sitting to walk on a treadmill before resuming their sedentary activity. They found that glucose and insulin levels in the children were lowered, as were other markers for aspects of metabolic syndrome.
In adults, a study conducted at Newcastle University found short bursts of exercise improved heart structure and diabetes management, seemingly reversing parts of the participants' negative health conditions -- which researchers said emphasizes the need for physical activity to be part of maintaining good health.
"This is an important finding, but more work is needed to inform existing physical activity guidelines for health," said Dr. Bert Bond, a professor at the University of Exeter. "The next step is to confirm these results on more participants, especially groups who are at greater risk of future cardiovascular disease, and to address the impact of longer high-intensity interventions."