It doesn’t take an expert to spot an off-season bodybuilding competitor compared to one preparing for a contest. Off-season bodybuilders show considerably less muscle definition and are usually far bulkier than their precontest appearance. Once you start dieting, the major goal is to lose as much bodyfat as possible, but there is always some loss of lean body mass, including muscle. Lifting weights is one of the best ways to minimize the loss of lean mass while dieting. Another aspect involves how quickly you lose weight.
Most scientists suggest that for purposes of maintaining as much lean mass as possible, dieting efforts should be long and slow. Attempts at rapid weight loss often produce an excessive loss of muscle. If you reduce total calories and carbohydrates too much, the body will dip into its protein stores, meaning muscle, when energy deficits become extreme. As a result, the general recommendation is to lose only one to two pounds a week.
A recent study compared two rates of weight loss, one fast and one slow, in a group of 30 elite athletes.1 Those in the slow-weight-loss group aimed for a weekly loss corresponding to 0.7 percent of bodyweight, while those in the fast-loss group aimed for 1.4 percent of bodyweight, rates that are equal to one to two pounds a week in a person weighing 154 pounds. All the athletes got 1.2 to 1.8 grams of protein per kilogram of bodyweight and four to six grams of carbs per kilogram of bodyweight a day and topped it off with a 20 percent fat intake. They ate five to seven meals and snacks daily, and none got less than 1,500 calories a day. All also took a recovery drink consisting of milk protein and carbs within 30 minutes after training. Creatine wasn’t allowed, but they were permitted a daily multivitamin-and-mineral supplement along with cod liver oil. They trained four times a week, working each muscle group twice per week.
Those in the slow-loss group increased their lean mass by 2.1 percent while losing bodyfat at the same time. They also improved on all performance tests, including those that measured strength and power. Those in the fast-loss group gained no lean mass, although they did lose bodyfat. Their performance increased only in the one-rep-maximum squat test. Those in the slow-loss group stayed on the diet for 8.5 weeks compared to the fast-loss subjects, who dieted for 5.3 weeks. Thus, those in the slow-loss group trained three weeks longer than the fast group, which could largely account for the gain in lean mass experienced by the slow group. Most of the lean mass gain was in the upper body, and the female subjects had the greatest lean mass gains, probably because they started out with the highest fat levels.
Based on those findings, the authors suggest that athletes who want to gain lean body mass and increase strength and power during a weight-loss phase that includes strength training should aim for a weekly weight loss of no more than one pound. Athletes who just want to maintain their lean body mass can increase their weekly weight loss rate to two to 2 1/2 pounds a week.
1 Garthe, I., et al. (2010). Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exer Metabol. 21(2):97-104.