Muscles and Metabolism
Aerobic activity is great for your heart and lungs. For many, it can
be a meditative way to clear the mind, blow off stress and get in touch with nature. For others, it’s a challenging and invigorating competitive sport. But as a tool for getting leaner, aerobic exercise by itself is a mediocre strategy.
Here’s the problem: To lose weight, you must burn more
calories than you eat. Stay in a calorie-deprived state long
enough, and your body begins to burn through its own tissues for fuel. Presto! The number on the scale goes down. You can make that number drop through aerobic exercise and calorie restriction. But what most bathroom scales won’t
tell you is how much of the weight you lose is in the form of fat, and how much of it is muscle. And losing muscle mass can sabotage your weight-loss efforts.
Muscle contraction is a primary engine of fat loss, explains Stella: The more muscle mass you have to contract, the more calories you can burn. In addition, strength-training workouts that take large muscle groups to a state of burn will increase the release of hormones that aid in reducing body fat. So anyone who wants to lose fat should make every effort to hang on to, and even gain, as much lean muscle mass as possible.
The Fat-Burning Machine
Numerous studies have demonstrated conclusively that strength
training, in conjunction with good nutrition, burns fat much more effectively than dieting alone and dieting in conjunction with aerobic exercise. What no study has shown yet is exactly how.
This much is known: Aerobic activity burns fat while you’re
exercising, but anaerobic (meaning without oxygen) activity burns fat in the minutes, hours and days following exercise, as your body recovers from your workout. Compare the energy costs of the two activities during a workout session, as many studies have done in the past, and aerobic activity appears to burn more fat, which may explain why many health and fitness professionals still recommend it.
The Power of Inefficiency
In addition to biochemical benefits, a progressive strength-training program also keeps you operating at maximal inefficiency. And that’s better than it sounds.
The problem with many repetitive exercise programs is that they
require progressively less energy the more you do them. That’s partly because repetition of any activity makes you more efficient: Your body gets better at performing that task. This is especially true if you’ve lost a significant amount of weight. Your body will naturally use less energy to move your new, lower weight. You’ll also expend less energy during low- to moderate-intensity exercise. This enhanced efficiency can be a major impediment if you’re trying to lose weight.
Your best bet, then, is to find ways to make your exercise program more inefficient. With aerobic exercise, you can mix it up: Alternate longer runs, rides or swims with some intermittent training — intervals in which you go hard for a short burst (30 to 60 seconds), then slow down to an easy pace for a minute or two. But it’s even simpler with strength training: Slap some
extra weight on the bar, or take some off. Do sets for time instead of stopping at a predetermined number of reps. Adjust your rest time between sets, do your exercises in a different order, or do different exercises altogether, and you have a new set of challenges to which your body has to adapt. Tweak your program regularly, and you can continue improving for as long as you keep up your strength-training efforts.
“Changing things up guarantees inefficiency,” says Lou Schuler, CSCS, coauthor of The New Rules of
Lifting for Life (Avery, 2012). “And that’s what you want
when you’re trying to create a metabolic stimulus for fat
At some point, says Cosgrove, health and fitness professionals may find out exactly what’s going on cognitively and metabolically, allowing them to devise programs that burn fat even faster. But for now, they aren’t sweating the details — and neither should you. “We’ve been wrong in the past about the mechanism behind it,” he admits. “For all I know, strength training simply summons the gods of fat loss. But we’re not wrong about the fact that it works.”
1. Why should a person who wants to burn fat try to gain as much muscle weight as possible?
2. What is the problem with repetitive exercise programs if you are trying to lose weight?
3.What is the benefit to making your exercise program more inefficient?
4. How can you apply the information you learned from this article to your life?