As little as 20 minutes of activity three times a week could go a long way.
Getting kids to exercise is hard. Getting kids to exercise a lot is harder. That’s always been a problem, but it’s even more so now, as a combination of cheap junk food, scaled back gym class time, extreme portions and online living have led to obesity epidemics in developed countries around the world—including among children.

Now there may be a simple way to mitigate the problem, if not solve it entirely: according to a new study published in the journal PLOS One, very short intervals of high-intensity physical activity could have a range of health benefits for kids, including lowering triglycerides and reducing body fat. Known by the kid-friendly acronym FFAB, for Fun Fast Activity Blasts, the exercises can yield benefits with as little as 20 minutes of alternating activity and rest, three times per week.

The study, led by Kathryn Weston, a senior lecturer in applied biosciences at Teesside University in the United Kingdom, was conducted in eight secondary schools in the Tees Valley region in northeast England. Weston and her colleagues recruited 101 students and divided them into two groups: one would receive the FFAB training in ten sessions over 13 weeks; the other would receive no intervention and simply be monitored. All of the students would go through physical exams beforehand which measured not just blood fat and body fat, but weight, blood pressure, glucose levels and more.

For the intervention group, each of the three weekly sessions began with five minutes of warming up followed by four 45-second bursts of activity, each of which was followed by a 90-second rest interval. At the end of the sessions there was a five minute period of cool-down exercise.

The students could choose from among four different types of exercise based around four different activities: basketball, boxing, dance and soccer. The basketball drills, for example, involved such activities receiving and returning a chest pass, then running to a cone and running back; and bouncing a basketball five times, then running to the end of a gym and running back. The dance exercises included high leg kicks while clapping pom poms under the elevated leg, and stationary high-knees running. All of the subjects in both the control group and the intervention group were also told to wear accelerometers during waking hours for one week before and one week after the study to measure overall activity level.

At the end of the study, both groups went through the same medical exams they had at the beginning. On at least three metrics, the intervention group was in distinctly better shape than the control group, with triglycerides 26% lower on average, waist circumference 1.5 in. (3.9 cm) smaller and 16 more minutes of daily physical activity recorded by the accelerometers, not including the exercise sessions. Blood pressure, total cholesterol, and HDL (or good) cholesterol were also better in the intervention group, though not quite at a level of statistical significance.

Certainly, the study was limited: a sample group of 101 is not terribly big and the short-term nature of the intervention does not demonstrate much either way about long-term results. However, the increased activity during non-exercise hours did suggest that once kids start moving more in a controlled setting, they may carry that over into their unmonitored hours.

Best of all, the researchers believe, is that the FFAB idea is, as they call it, “novel and scalable,” a relatively untried approach that would be easy to implement in a larger and more sustained way. At a time when too many kids are suffering the physical consequences of getting almost no exercise at all, even a little bit might make a big difference.

<span class="byline"><a href="http://time.com/author/jeffrey-kluger/">Jeffrey Kluger</a></span>

<a href="http://time.com/4434878/physical-education-childhood-obesity/" target="_blank">http://time.com/4434878/physical-education-childhood-obesity/</a>