ADOLESCENT SPRINT ATHLETES GROW NORMALLY WITH ADEQUATE PROTEIN INTAKE

Aerenhouts, D., Poortmans, J. R., Deriemaeker, P., Hebbelinck, M., & Clarys, P. (2010). Protein needs in adolescent sprint athletes: a longitudinal study. Presentation 795 at the 2010 Annual Meeting of the American College of Sports Medicine, Baltimore, Maryland; June 2-5.

red line

This study estimated the protein needs for adolescent sprint athletes. A seven-day diet diary, during which period 2 x 24-hour urine samples were collected, was administered five times with six-month intervals to adolescent sprint athletes (M = 33; F = 32). Anthropometric data were collected allowing the estimation of skeletal muscle mass. Diaries were analyzed for nutrient intakes using the Belgian and Dutch food data banks. A cut-off value of 1.1 x basal metabolic rate was used to check for underreporting. During the 24-hour urine collections, Ss ingested 3 x 180 mg of para-amino benzoate. Urine collections containing a minimum of 85% para-amino benzoate were analyzed for their nitrogen content.

Mean daily protein intakes remained within a narrow range of ~1.4 - 1.5 g/kg in girls and ~1.5 - 1.6 g/kg in boys. For both genders, a protein intake around 1.4 g/kg was required to be in a positive nitrogen balance. This remained stable throughout the experimental period. Height and weight evolution was comparable to that of Belgian peers. A gain in body height, weight, or skeletal muscle mass did not alter nitrogen balance in either gender. There was no significant relationship between protein intake and a gain in height, weight, or skeletal muscle mass.

Implication. A daily protein intake between ~1.3-1.5 g/kg appears adequate to sustain a positive nitrogen balance in adolescent male and female sprint athletes. Sufficient protein was provided through the diet in most of the athletes studied.

Return to Table of Contents for this issue.

red line