Four Seconds of Intense Exercise Can Boost Fitness

According to a recent study published in Medicine & Science in Sports & Exercise, four-second intervals of high-intensity training could help improve overall fitness in sedentary adults. Exercise physiologists at the University of Texas recruited 39 men and women, aged 50 to 68, and had them train in a performance lab three days a week. While there, the volunteers were put on a specialized stationary bike, and tasked with “sprinting” four seconds a time (followed by a 56 second rest). They did this for 15 minutes, totaling 60 seconds of sprint time.

A couple months later, the subjects were all capable of performing the workout with just 26 seconds of rest in between the four-second sprints. Fitness metrics indicated a 10% increase in body health, highlighted by muscle mass growth and cleaner arteries. The study’s results are in line with a growing body of research which suggests shorter, fiercer exercise — designed to shock the body — could have a more serious impact on longevity than longer, more forgiving workouts.

Even amongst the list of science-backed HIIT training, though, this sort of study is a revelation. Recent studies have sung the praises of four to 10 minutes of hard work. Four seconds is an entirely different ballgame. Crucially, the researchers used ordinary, older adults for the latest iteration of their study. (Earlier in the year, they’d put college athletes on the bike.) The exercise intimidation barrier for aging men and women can be high. But this sort of research promises that giving one’s “max effort,” and reaping all the positive life changes it can bring, doesn’t have to necessitate minutes of agony.

The study’s bike is not available to the public — nor are the study’s researchers, who made sure to yell consistent commands at the trainees — but you can work out in intense four-second intervals on your own. Run up a hill in your neighborhood or the bleachers at the local field. Perform a series of box jumps. Fish out a jump rope for quick bursts. Do jumping jacks. We’re all busy, yes. But if four seconds is really enough to put years on your life, you have to be better than your “best” excuse.