When training it is imporatnt to make sure you are eating nough calories and geting enough nutrient to supoort physiological adapation, even if you are trying to loose weight. Here is an exerpt from a postistion statement compiled by: American College of Sports Medicine: Nancy R. Rodriguez (University of Connecticut); American Dietetic Association: Nancy M. DiMarco (Texas Woman’s University); Dietitians of Canada: Susie Langley
Energy balance occurs when energy intake (the sum of energy from foods, fluids, and supplement products) equals energy expenditure (sum of energy expended as basal metabolic rate, the thermic effect of food, the thermic effect of activity, which is the energy expended in planned physical activity, and non-exercise activity thermogenesis).
Energy expenditure for different types of exercise is dependent on the duration, frequency, and intensity of the exercise, the sex of the athlete, and prior nutritional status in addition to heredity, age, body size, and fat free mass. The more energy used in activity, the more calories needed to achieve energy balance.
Inadequate energy intake compromises performance and negates the benefits of training. With limited energy intake, fat and lean tissue will be used for fuel by the body resulting in a loss of lean tissue. The concern here is that loss of strength and endurance, as well as compromised immune, endocrine, and musculoskeletal function can result.
