Is Time Magazine right: ‘Exercise won’t make you thin’?


I’ve been training for my first half marathon over the past few months, and it’s definitely been rewarding. Never before had I dreamed of running for hours straight and working out for more than three days in a row. But, I’ll be honest—I didn’t just sign up for the love of running. By entering this half marathon, would be committed to exercising on a regular schedule, and hopefully lose a few pounds in the process.  Recently, however, more and more researchers are claiming that exercise does not go hand-in-hand with weight loss, and that exercise could in fact be keeping you from shedding pounds.

Treadmill Running

According to a well-known exercise researcher Eric Ravussin, who is the chair in diabetes and metabolism at Louisiana State University, exercise is useless for weight loss. At the root of this issue is the concept that exercise, while expending calories, also stimulates hunger. Our bodies will want food after a long sweat-session, and this exercise may even cause us to eat greater amounts. Therefore, exercising may not only be ineffective in aiding weight loss, but could potentially make it harder for a person to lose weight.

Steven Gortmaker, who heads Harvard’s Prevention Research Center on Nutrition and Physical Activity, explains. “The most powerful determinant of your dietary intake is your energy expenditure,” he says. “If you’re more physically active, you’re going to get hungry and eat more.”

A study conducted by Louisiana State Professor Timothy Church showed that there is even more behind this problem than stimulated hunger. He argues that after exercising, people feel the need to compensate in two ways. First, by rewarding themselves with food they may not normally eat (isn’t a second helping of apple pie fine on a day that I’ve gone to the gym?). Second, people compensate by being less active for the rest of the day, spending more time being sedentary in front of the TV or computer.

The Los Angeles Times wrote a great article on how the Time Magazine piece may be a little misrepresented.  You can find it here.

In order to avoid excess cardio that could trigger hunger, you could opt for shorter, higher intensity workouts that are also more efficient. High intensity interval training (HIIT) utilizes short, high speed cardio followed by low intensity recovery periods. These workouts can take less than half the time of usual long and often dull cardio workouts, and are best performed while sprinting but can also be effective on a bike or elliptical trainer.

A typical HIIT workout consists of a warm up period, repetitions of very high intensity  (usually about 15 to 20 seconds) paired with a recovery period (about 10 seconds), and ending with a cool down. These workouts are usually only 10 to 20 minutes, but create great results because of the bursts of cardio, which are executed near a person’s maximum intensity.

Further, experts say that after a HIIT session, your metabolism will be revved and you will burn fat up to 24 hours after your workout, as opposed to low intensity runs or bike rides, in which fat burning only occurs while you are exercising.

So, for all the cardio-junkies out there, it may be beneficial to cut down on your usual workout time, or opt for shorter, high intensity interval sessions and see how this affects your appetite. As for me, while I know I am becoming stronger and doing my body good by training for this half marathon, it truly is much more about what you eat rather than what you work off when it comes to losing weight.

Yours in Health,

Stella Metsovas B.S., CCN