Assessment of basal metabolic rate in adolescent athletes

Objective. To assess the intensity of basal metabolism in adolescent elite athletes. Patients and methods. This study included 154 adolescent athletes (42 boys, 112 girls) aged 13–18 years (mean age: 15.3 ± 2.5 years). Basal metabolic rate (BMR) was measured in all participants using respiratory indirect calorimetry and the Harris–Benedict equation. Study design: single-center, cross-sectional, randomized, uncontrolled. Results. An increase in BMR was revealed in 79 (51%) participants, normal BMR – in 50 (33%) participants, and a decrease in BMR – in 25 (16%) participants. Increased BMR was statistically significantly more common in boys compared to girls (83% and 39% respectively, p = 0,01), whereas decreased BMR was more characteristic of girls compared to boys (20% and 4%, respectively, p = 0.001). Conclusion. Most adolescent athletes show an increase in BMR, which reflects an adaptation of the organism to high physical exertion. A decrease in BMR may indicate the presence of relative energy deficiency in athletes. The Harris–Benedict equation significantly underestimates the value of BMR in adolescent athletes and is not an alternative to respiratory indirect calorimetry when individual assessment of energy expenditure is necessary as part of biomedical support. Key words: children, high-performance sport, basal metabolic rate, indirect calorimetry