Although resistance training typically uses less energy per hour than aerobic exercise, bodybuilders have been found to have high total energy requirements because of their tendency to undertake long and frequent resistance training workouts. Also, individuals with a higher relative muscle mass burn off more calories at rest, as muscle tissue is highly metabolically active. This means more calories will be burned during the day just keeping the body 'ticking over'.

Researchers have found that not consuming enough calories can inhibit muscle mass gains. For example, in one study the addition of a 540 calorie supplement to self-selected diets in competitive male weight lifters over 15 weeks caused an increase in lean body mass equal to that of a group of weight lifters using anabolic steroids!

This has led sports nutritionists to suggest that strength athletes should just focus on getting enough calories rather than worrying too much about protein intake. It's sensible to keep fat intake moderate, however. The best strategy is probably to increase the number of meals and snacks eaten per day.