1 Minute of All-Out Exercise May Have Benefits of 45 Minutes of Moderate Exertion

1 Minute of All-Out Exercise May Have Benefits of 45 Minutes of Moderate Exertion, by Gretchen Reynolds, from 2016.

For many of us, the most pressing question about exercise is: How little can I get away with? The answer, according to a sophisticated new study of interval training, may be very, very little. In this new experiment, … 60 seconds of strenuous exertion proved to be as successful at improving health and fitness as three-quarters of an hour of moderate exercise. …

High-intensity interval training [is] a type of workout that consists of an extremely draining but brief burst of exercise — essentially, a sprint — followed by light exercise such as jogging or resting, then another sprint, more rest, and so on. …

In the past few years, exercise scientists and many of the rest of us have become intrigued by the idea of exercising exclusively with intervals, ditching long workouts altogether.

The allure of this approach is obvious. Interval sessions can be short, making them a boon for anyone who feels that he or she never has enough time to exercise. …

But because of time and funding constraints, most studies of interval training have had limits, such as not including a control group, being of short duration or studying only health or fitness results, not both. …

Scientists at McMaster University in Hamilton, Ontario, … decided recently to mount probably the most scientifically rigorous comparison to date of super-short and more-standard workouts.

They began by recruiting 25 out-of-shape young men and measuring their current aerobic fitness and, as a marker of general health, their body’s ability to use insulin properly to regulate blood sugar levels. The scientists also biopsied the men’s muscles to examine how well their muscles functioned at a cellular level. …

By the end of the study … the endurance group had ridden for 27 hours, while the interval group had ridden for six hours, with only 36 minutes of that time being strenuous.

But when the scientists retested the men’s aerobic fitness, muscles and blood-sugar control now, they found that the exercisers showed virtually identical gains, whether they had completed the long endurance workouts or the short, grueling intervals. In both groups, endurance had increased by nearly 20 percent, insulin resistance likewise had improved significantly, and there were significant increases in the number and function of certain microscopic structures in the men’s muscles that are related to energy production and oxygen consumption.

The upshot of these results is that three months of concerted endurance or interval exercise can notably — and almost identically — improve someone’s fitness and health.

There are a bunch of these fitness programs now, on YouTube and around the web, such as here.