How to heal your metabolism

Change in training and diet can slow even an athlete’s engine—but there's a fix.

Metabolism is often written off as something you’re blessed with or you’re stuck with. It’s sky-high because you’re an athlete; or slow because of genes you have no control over.

But neither is true. Metabolism is frequently misunderstood, says Brian St. Pierre, R.D., C.S.C.S., the director of performance nutrition at Precision Nutrition. What it is: a finely-tuned machine that ebbs and flows—and even athletes can see blips in how well their body churns along.

The best way to keep a fit body in high gear is to know how your metabolism functions (and how to feed it):

Metabolism isn't written in your genes.
To some extent, blaming your mom for a lackluster metabolism is fair. Basal metabolic rates (the number of calories your body needs to function) vary from person to person, says St. Pierre. But he points out that research shows that basal metabolic rate alone doesn’t make you any more likely to gain weight compared to someone with a speedier metabolism. Your genes are not your weight fate.

Master the basics to keep things kicking, suggests St. Pierre: Eat plenty of protein (four to six palm-sized portions a day for women, and six to eight for men) and minimally processed food; move around outside of your workouts; sleep enough; and manage stress. If you’re trying to drop weight, go slow—aim for a half to one pound per week, he says.

Workout ruts require diet changes.
Go into a rest and recovery period, and you might see the scale tick up. With less exercise, you’re likely in a calorie surplus and metabolism doesn’t adjust to new patterns of movement immediately. Fortunately, the weight gain—and lagging metabolism—is likely temporary. Metabolism will rise back up, but how quickly this happens is individual, says St. Pierre.

If you’re injured or are going to be away from the gym for a while, the (less-than-ideal) guidelines are simple: Eat less while your body adjusts to your lack of movement. Listen to your body, too. Your appetite hormones might tell you you’re full after a small serving when you're used to going back for seconds, for example, says St. Pierre. And active or not, make sure your diet is still balanced. Healthy fats, protein, and carbs all fuel your energy, brain, hormones, and body in different ways.

Once you start sweating again, incorporate resistance and cardio workouts, as well as recovery (walking or yoga) sessions, advises St. Pierre. This will help you maintain muscle mass, burn calories, and decrease stress.

You must fuel to train.
Under-eating in relation to exercise habits can temporarily slow certain components of your metabolic rate. That’s because your brain senses how many calories are going out and coming in and tries to match that, St. Pierre explains. One component it might alter is how much you move around outside of exercise. You might feel lethargic and, thus, you won’t move around as much—that's your body’s way of conserving energy.

If you’re female and notice low energy plus other symptoms—namely a missing or irregular cycle and bone loss or osteoporosis—you could be suffering from Female Athlete Triad, a condition characterized by these three issues. This can be a result of improper nutrition, as (because of hormones) women’s bodies are more sensitive to limiting carbs or calories, says St. Pierre.

The right amount of fuel is crucial for fitness and metabolism, and athletes need not fear carbs. St. Pierre recommends most active women eat four to six handfuls of carbs a day; and that men eat six to eight. Go straight to nutritious sources like whole grains, potatoes, beans and legumes, and fruit.