The relationship between aerobic and anaerobic exercise capacities in pre-pubertal children
Creators: name: Prasad, Navin
Publisher: name: University of British Columbia
Year: 2009

description: It is well established in athletic adult individuals that specialization to an aerobic or anaerobic phenotype can occur. Less is known about this specialization in children. While childhood participation in organized sports is increasing, very little is known about the physiological potential of young athletes. For example, the development of the aerobic and anaerobic energy systems in relation to each other in children is not well known. Many children are being put on training programs before puberty without any knowledge as to whether or not this can influence specialization to an aerobic or anaerobic phenotype. Early authors basing their results on twin studies, suggested a strong genetic component to aerobic or anaerobic phenotypes (Klissouras et al., 1973). This was not confirmed by muscle biopsy studies in children (Bell et al., 1980) and in fact Bouchard et al. (1992) have proposed a strong environmental or training influence to athletic performance. The purpose of this study was to look at the question of metabolic specialization in prepubertal children before they had any influence of growth or maturation or training effects. The hypothesis was that if specialization exists, then those children with the better anaerobic capacity would have the lower aerobic capacity and vice versa. An attempt was made to screen out the better sprint and endurance performers with field tests, as it was felt that if specialization was occurring it would most likely be present in this group of individuals. A total of 42 pre-pubertal children from one school completed the study. Mean age was 9.31 years (range 8-11 years). All children initially completed field tests of 50 yard run and 1600 yard run to determine the best sprint and endurance performers. The sprint group (S) performed the 50 yard run under 8.50 seconds, while the endurance group (E) ran 1600 yards under 8 minutes. A questionnaire was filled out to exclude subjects who were involved with a track club or regular training program. On a separate day laboratory tests and anthropometric measures were performed. The laboratory tests performed in random order consisted of a Wingate protocol for anaerobic parameters on one day and a Quinton cycle ergometer test for aerobic parameters on another day. Statistical analysis consisted of a zero order correlational analysis for the dependent variables of age, sex, height, weight, sum of skinfolds, sprint run time, endurance run time, anaerobic capacity, peak and mean anaerobic power, and aerobic capacity. In addition a Hotelling's T 2 test was performed to determine significant differences between the sprint and endurance groups. The results showed no significant differences between the sprint or endurance groups with respect to anthropometric or laboratory measures. There was a trend for the sprint group to have higher peak anaerobic power 9.43 ± 0.87 W/kg (S) versus 8.67 ± 1.25 W/kg (E). However, they also showed a trend towards higher aerobic power 52.03 ± 7.97 ml/kg/min (S) versus 47.73 ± 9.25 ml/kg/min (E). This suggests no specialization. In addition the correlational analysis showed high positive correlations between mean anaerobic power and V02max (r = 0.88) and peak anaerobic power and V02max (r = 0.82) suggesting that those children who do best aerobically also do best anaerobically in the pre-pubertal age group. The evidence provided from this study suggests that pre-pubertal children are metabolic non-specialists. Therefore rigorous training programs trying to implement aerobic or anaerobic specialization in this age group are likely not beneficial. The specialization seen in adolescents and adults may be secondary to growth or maturational changes after puberty and this would most likely be the better stage to begin regular training programs in children.