"Even with the ideal weight-loss program, you are bound to lose a certain amount of lean muscle along with the fat," says Daniel Vigil, M.D., a team physician for the U.S. track and field team. The human body has a few energy storing options, and when you lose weight, energy stores are taken from all the interrelated compartments. "So you'll burn fat while you're burning carbohydrates—and at the same time you'll be burning protein, which is actually muscle mass," explains Dr. Vigil. "But as long as your weight loss program does not include poor nutrition or dehydration, your strength will return as your muscle mass is restored through weight training."
What exactly is the right weight-loss and weightlifting formula to save your strength? "Ideally, when you are exercising and dieting, you don't want to lose more than two pounds a week," says Malachy McHugh, Ph.D., research coordinator at the Nicholas Institute of Sports Medicine and Athletic Trauma at New York City's Lenox Hill Hospital. "Losing weight at a slower rate will help you to avoid significant muscle mass loss or a decrease in muscular energy—and you won't run into dehydration problems." A recent study conducted at Ball State University in Muncie, Indiana, reinforces this point: Findings showed that when study subjects cut calories while maintaining a resistance training and aerobic exercise regimen, they were able to maintain muscle mass.