Spring is on the horizon, and with it, warm weather and sunlight. While sheer vanity should never be the primary motivation for maintaining an active lifestyle, there is nothing wrong with wanting to look good poolside or at the beach. Even if it is the lone incentive for some individuals, they are still better off exercising for the wrong reason than remaining sedentary or otherwise unenthused with the concept of getting in shape.

It is well documented that weight loss, though important to gauge, should not be the fundamental barometer for physical wellness. Still, burning fat is a simple way to simultaneously feel better and look slimmer, thus it remains the carrot on the stick for many across the country. This pursuit, and the best means of attaining it, was the subject of Gretchen Reynolds’ recent column for The New York Times, which looked at a new study published in The British Journal of Sports Medicine.

After pointing out the differences that make this study distinct, Reynold details the thorough efforts of the researchers, writing:

Scrolling through medical library databases, they eventually found 36 studies that involved randomized experiments — not surveys or other epidemiological data — comparing the effects of endurance training to those from interval workouts. The experiments had to have lasted at least a month and included body-composition measurements at the start and finish, even if changes to body fat had not been the primary focus of the study. (And in most of these experiments, they were not.)

Then the researchers pooled numbers from the studies, giving them a total of more than 1,000 participants, young and old, male and female.

The moderate-exercise routines used in the studies varied considerably, with some involving walking and others jogging, cycling or swimming. In general, the endurance-style workouts lasted for about 40 minutes.

The interval sessions likewise differed from one study to the next, but most involved intervals lasting for a few minutes at a time, at a pace just below all-out effort, which is typical of H.I.I.T. Others required a few seconds of absolutely all-out exertion, an approach the researchers dubbed sprint-interval training, or S.I.T. 

Then the researchers simply compared fat loss after the different exercise programs.

The results should be encouraging for anyone who exercises. Both moderate training and intervals, of all types, led to reductions in body fat, the researchers found. These reductions were absolute, meaning that people shed some of their actual fat mass, and also relative, meaning that they lowered the percentage of their body mass that was fat.

The changes also for the most part occurred whether or not people lost a noticeable amount of overall weight, suggesting that they might be losing fat while gaining muscle.

Perhaps most important for people drawn to quickie exercise, interval training, especially S.I.T. workouts, often burned more fat, in absolute terms, than prolonged, moderate exercise, with interval trainers dropping an average of about 3.5 pounds of fat during most studies, versus about 2.5 pounds for moderate exercisers.

While any exercise is better than no exercise, the increased demand for high intensity interval training workouts in recent years cannot be denied. Gyms and health clubs across the country now feature equipment and classes to accommodate those interested in adding HIIT to their routine or giving it a try, including popular national brands like L.A. Fitness and My Sports Clubs (Boston, New York, Washington and Philadelphia).

To read Reynolds full writeup, click here.