PARENTS' HEALTH PRIMARY : RESEARCH-1

FITNESS : The benefits of interval workouts :

In what is probably the definitive word on how little exercise we can get away with, a new study finds that a mere four seconds of intense intervals, repeated until they amount to about a minute of total exertion -

Leads to rapid and meaningful improvement in strength, fitness and general physical performance among middle-aged and older adults.

The study relied on type of specialized stationary that is not widely available, but even so, the result suggests that strenuous but super-abbreviated workouts can produce outsize benefits for our health and well-being.

I have often written about the the potential benefits of brief, high intensity interval training or H.I.I.T., an approach to exercise that consisted quick spurts of draining physical efforts, followed by rest, with the sequence repeated multiple times.

In studies, short H.I.I.T, workouts typically produce health gains that are equal to or more pronounced than much longer, gentler workouts.

But the ideal length of the intervals in these workouts has been unsettled. Researchers studying H.I.I.T agree that the optimal interval span should stress out muscle and other bodily systems enough to jump start potent physiological changes but not so much that we groan, give up and decline to try that workout ever again.

In practice, those dueling goals have led H.I.I.T scientists to study intervals ranging from protracted four minutes to a quickie 20 seconds.

But Ed Coyle, an exercise physiologist at the University of Texas in Austin, and his graduate assistant Jakob Allen suspected that even 20-seconds spurts might exceed some exercisers' tolerance. So they started looking for the shortest interval that was still effective.

And in the new study, published in Medicine & Science in Sports & Exercise, he and his colleagues settled on a blink-swift four seconds.

They arrived at that number by by first working with competitive athletes at the university's human performance lab. Muscular and fit, the athletes generated enormous speed and power on specialized stationary bicycles that feature a heavy flywheel and no resistance.

During fitness testing on these bikes, most of the athletes would reach their maximum power output and all-out aerobic efforts after about two seconds of hard pedaling. [Dr. Coyle ha equity in the company that manufacturers the bicycles , but said this monetary involvement has not affected research results from his lab].

The Publishing of this Health & Fitness post continues to part 2. The World Students Society thanks author Gretechen Reynolds.