Q. Does aerobic exercise interfere with muscle gains from weightlifting?
If you're training for an endurance event like a marathon, when you might run 60 miles or more per week, you'll almost always see a decrease in your muscle mass. For most of us, who do more moderate amounts of physical activity, there will be minimal, if any, loss in muscle mass -- so there's nothing to worry about.
If you do plan on lots of aerobic exercise and are concerned about losing muscle, try starting with 20-30 minutes of moderate aerobic exercise (at 50% to 70% of your maximum heart rate) two to three days per week, and see how it goes.
Q. Should I hold off on weight training until I lose weight?
Absolutely not. Lifting weights will not only help you lose weight, but maintain the loss. Here's why:
- Muscle keeps your metabolism revved up, burning calories, fat, and glucose (sugar).
- When you lose weight, up to 25% of the loss may come from muscle, resulting in a slower metabolism. Weight lifting will help preserve or rebuild any muscle you lose by dieting.
- Muscle helps you with aerobic exercise. The stronger you are, the better you will be at any aerobic activity.
- Weight training improves your body's muscle-to-fat ratio (you end up with less body fat and more muscle), which improves both your health and your fitness level.
- Gaining muscle will help you look better as you define and tone your physique.
- Building strength helps you feel good about yourself. Although the scale may show a slight weight gain when you start lifting weights (usually five pounds or less), you probably won't look heavier because the gain is in muscle, and your clothes may even fit more loosely.