Different types of exercise enhance your metabolism in different ways. You’ll get the best results by combining them in a balanced program appropriate for your current fitness level.
Builder 1: Heart-rate cardio training plus weightlifting
Heart-rate, or zone-based, cardiovascular training is one of the best metabolic boosters around, says Jeff Zwiefel, vice president of fitness, training and new program development for Life Time Fitness. Exercising in the five different heart-rate zones at different intensities yields unique metabolic benefits, such as increased aerobic capacity, maximized caloric burn and improvements in the way your body burns fat as a fuel source.
You may spend more time training in one zone than another based on your fitness level and specific goals. For the greatest range of metabolic benefits, though, incorporate all zones into your exercise program (unless you have a medical reason not to), either on separate days or in a single workout by using interval training.
But don’t neglect weightlifting and other forms of resistance work that help you build sleek, powerful muscles. For one thing, those muscles make you stronger (and thus make exercise easier). For another, accumulating lean tissue increases your body’s metabolic rate. That’s because, pound for pound, muscle burns more calories than fat.
How much more? According to a 2001 report published in the Current Opinion in Clinical Nutrition and Metabolic Care, even at rest, muscle tissue is three times more metabolically active than fat, with muscle burning about 6 calories per pound per day compared to fat’s 2. A daily difference of 4 calories per pound may not sound like a lot, but it adds up. Put on 5 pounds of muscle and your body will automatically start burning an extra 30 calories per day. That amounts to about 10,950 per year, which might net you another 3-pound fat loss, thus improving your lean-to-fat ratio and potentially boosting your metabolism even more. Over the course of a few years, this type of increased metabolic activity can make achieving and maintaining your ideal weight far easier.
Does that mean you can just crank on the weights and forget cardio? Nope. First, cardio’s heart-health benefits are too good to ignore. Second, cardiovascular exercise typically burns considerably more calories than weight training does, and it eclipses the calories you can burn by merely accumulating lean tissue. For example, a 150-pound person bicycling or jogging at a moderate pace (12 to 14 mph cycling, 5 mph jogging) burns about 360 calories in a half-hour. That same person doing light to moderate weight training will burn 135 calories in the same amount of time, and even if she boosts the intensity for a vigorous weight workout she’s looking at 270 calories well under the cardio expenditure.
Another reason to do both types of exercise: They both produce a metabolic “afterburn” effect called excess postexercise oxygen consumption (EPOC), which can increase your body’s rate of caloric burn for up to two hours after you exercise (net burn: anywhere from 5 to well over 150 additional calories). The EPOC for cardio and resistance workouts is about the same, assuming intensity and total calorie burn are similar, according to a 2004 report in the Journal of Strength and Conditioning Research. But because cardio generally burns more calories per minute, for workouts of the same time length, cardio has the EPOC advantage.
Builder 2: Exercise variety
Mixing things up keeps your mind motivated, but it also optimizes your caloric burn rate, Chek says. His recipe for a potent metabolic boost: Pick several different aerobic activities, then do three to five minutes of each in circuit fashion. Or at least pick a different activity for each workout. “The idea is to keep your physiology guessing,” he says.
Chek explains that your body is designed to conserve energy, and it does so by becoming more fuel efficient at performing whatever activity you ask of it. The more efficient it becomes, the less energy (read, calories) it uses to perform the same task. Frequently changing and upgrading your fitness routine keeps your body constantly adapting, so it has to bring its A-game each and every time. The same goes for weight training. Varying exercises, equipment, reps and sets, amount of weight, and pacing will all help keep exercise fresh.
Buster 1: No exercise
Bottom line: Any exercise is better than no exercise. Being sedentary means you miss the immediate metabolic boost of the activity itself, plus the chance to increase your calorie-guzzling muscle tissue. Sit too long, and all your body’s systems slow to a crawl. A sedentary lifestyle also contributes to ill health and depression, which further reduce your energy and make moving even less appealing.
Buster 2: Inadequate exercise recovery
“Overtraining is not just something that happens to competitive athletes. It affects people in all gyms,” says Paul Robbins, metabolic specialist for Athletes’ Performance in Tempe, Ariz. If you are exercising intensely on a daily basis, at least one recovery day a week is critical, no matter what your fitness goals are. And you may need more, because the growth-producing, strength-enhancing changes that exercise stimulates occur during rest, not during exercise itself. He notes, “Without time to rest and recuperate, you’ll never be strong enough to hit those training high notes like you should.”