"There are so many factors that determine your metabolic rate," says Janet Rankin, PhD, professor of human nutrition, foods, and exercise at Virginia Tech. Among them: your height and weight (bigger people burn more calories), your gender (women have slower metabolisms than men), your age (your metabolic rate declines as you get older), how much muscle or fat you have (muscle burns more calories than fat does), and your DNA.
Although you can’t rewire your double helix or switch back the clock, there’s still plenty you can do to be a fast burner, Rankin says. All you need to do is remember these four research-backed truths.
Cardio revs your metabolism forhours afterward
Resistance training often hogs the metab-boosting spotlight. It’s no wonder, since a pound of muscle at rest fries three times as many calories as a pound of fat. However, cardio is every bit as crucial for keeping your metabolism humming. New research explains why: In a study published in Medicine & Science in Sports & Exercise, people pedaled a stationary bike as hard as they could for 47 minutes. The finding: They slashed 190 calories above their resting metabolic rate for 14 hours after their workout. Add that to the 519 calories, on average, the cyclists scorched from the workout itself, and that’s one heck of a sweat session. "If you do just two to three vigorous bouts of exercise per week for 45 minutes, you could lose a pound of fat every two weeks from the combination of calories expended during exercise plus what you burn afterward," says study author David Nieman, PhD, a professor of exercise science at Appalachian State University.
So how can you tell if you’re pushing hard enough? Any sweat-inducing activity you can sustain for 45 minutes will do the trick.
Skimping on sleep stalls your calorie-burning
You’d think that more hours awake means more opportunities to sizzle calories, but the truth is that more sleep makes for a quicker metab. In fact, a single sleepless night reduces your resting metabolic rate by about 5% several hours into the next day, according to a study in the American Journal of Clinical Nutrition. What’s more, the morning after skipping sleep you burn 20% fewer calories from diet-induced thermogenesisthe number of calories your body uses to break down and digest food.
As if that wasn’t enough to encourage you to power down your iPad early, scientists have found that women consume 329 more calories, on average, after snoozing for four hours than they do when they sleep for nine. To keep your cravings in check while preventing your engine from sputtering, try to get seven to eight hours of sleep per night.