Lose fat without losing muscle by doing heavy strength training and getting the right dose of protein. A serious problem for athletes who need to decrease body mass by restricting energy is a simultaneous loss of muscle, which can lead to impaired performance. There are a few proven training and dietary methods that will allow you to avoid this.
A recent study presented at the 8th International Conference on Strength Training in Norway attempted to identify the ideal dose of energy restriction so as not to compromise strength and power output in athletes. The study had elite athletes reduce their energy intake by either 500 or 1,000 calories a day in order to lose 5 percent of their body weight.
Results showed that although it took athletes three weeks longer to lose the weight when they restricted energy by 19 percent than when they restricted it by 30 percent, the greater daily energy intake allowed them to gain 2.1 percent muscle mass at the same time. The group that restricted calories by 30 percent lost 5 percent of body weight in 5 weeks and lost an insignificant 0.2 kg of muscle.
Both groups did a heavy weight training program in conjunction with regular sport training. The group that reduced calories by 19 percent (the slow reduction group) had a much better body composition performed better on strength and power tests than the fast reduction group. The slow reduction group jumped 7 percent higher in a countermovement jump test, increased squat 1 RM by 12 percent, and lifted an average of 11.4 percent more on upper body strength and power tests. The fast reduction group did not improve jump height and only increased squat 1RM by 8 percent and upper body performance by 5 percent.
The take away is that if you choose to lose fat by reducing energy intake, you should continue with heavy strength training and aim for a body fat loss of about 0.7 percent per week. Greater energy reduction will lead to poorer performance and may cause muscle loss.. Also, energy restriction without additional strength training will lead to significant muscle loss, especially if endurance exercise is performed as well.
A second method for fat loss without muscle loss is to modify macronutrient intake. For example, a study of elite male gymnasts showed that putting them on very low-carb diet in which they ate 54.8 percent fat, 40.7 percent protein and 4.5 percent carbs (carbs totaled no more than 28 grams, strictly from green vegetable sources) for one month with training produced a 2 kg loss of body fat had no decrease in muscle. Just as important, the gymnasts performed equally well on strength and power tests before and after the low-carb diets.
The take away is that eating a high-protein, low-carb diet is likely the optimal method for improving body composition for athletes because it doesn’t require energy restriction. Researchers point to a “threshold” protein dose necessary to avoid muscle loss—it may be as high as 2.8 g/kg/bw a day in athletes doing high-volume training.
Paoli, A., Grimaldi, K., et al. Ketogenic Diet Does Not Affect Strength Performance in Elite Artistic Gymnasts. Journal of the International Society of Sports Nutrition. 2012. 9(34).
Garthe, Ina. Changes in Body Composition and Performance in Elite Athletes During A Period with Negative Energy Balance Combined with Strength Training. Eighth International Conference on Strength Training. Norwegian School of Sports Sciences. October 2012.