Abbreviated, intense workouts may help people of any age become healthier, a new study of old mice that ran on treadmills suggests. Although the experiment involved rodents, not humans, the study found that old mice can tolerate high-intensity interval training and rapidly gain fitness and strength, even if they start off frail and exercise for only a few minutes a week.

In recent years, high-intensity interval training has generated considerable attention among exercise scientists and practitioners. In this type of workout, you perform repeated, brief bursts of very intense exercise interspersed with longer periods of easy recovery.

The primary allure of high-intensity interval training is, for most of us, its brevity. A typical high-intensity workout lasts less than 15 minutes, including a warm-up and cool-down, but has been shown in multiple studies to provide health and fitness benefits that are the same as or greater than an hour or more of continuous and relatively moderate exercise.

Much of the research into short, intense exercise, however, has centered on its benefits for healthy adults, usually those below the age of 50. One famous and still ongoing study in Japan recruited adults past age 55 and found that interval walking — in which volunteers stride briskly for three minutes and then slowly for another three — enabled the older men and women to improve their endurance and blood pressures to a greater extent than walking moderately for the same amount of time.