Effect of chronic hypoxia and socioeconomic status on anaerobic power of 10- to 12-year-old Bolivian boys.

Abstract

The aim of this study was to analyze the effect of chronic high altitude hypoxia and socioeconomic status on the anaerobic power, developed during short-term maximal exercises, of prepubertal Bolivian boys. We studied 67 prepubertal boys (9-12.6 years) at high altitude in La Paz (3600 m, Bolivia); 23 were from a high socioeconomic background (HAHSES) and 44 from a low socioeconomic background (HALSES). The group studied at low altitude in Santa Cruz de la Sierra (420 m, Bolivia) consisted of 78 boys of the same age; 30 were from a high (LAHSES) and 48 from a low (LALSES) socioeconomic background. Maximal anaerobic power (Pmax) was determined by a force-velocity test and mean anaerobic power (P) was measured by a 30-s Wingate test. The tests were realized at high and low altitude on the same calibrated cycle ergometer. At both high and low altitudes, Pmax expressed in absolute terms or relative to body weight were significantly higher in boys of high socioeconomic status (HAHSES: 6.8 +/- 1.0; LAHSES: 7.1 +/- 1.0 W.kg-1 BW) than in boys of low socioeconomic status (HALSES: 5.5 +/- 0.8; LALSES: 5.3 +/- 0.9 W.kg-1 BW). However, there was no significant difference between highland and lowland boys of the same socioeconomic class. The same observations were obtained for P (HAHSES: 5.2 +/- 0.8; HALSES: 4.5 +/- 0.9; LAHSES: 5.2 +/- 0.7; LALSES: 4 +/- 0.6 W.kg-1 BW). To conclude, boys of the same socioeconomic class at high and low altitude had the same anaerobic power. However, regardless of altitude, low socioeconomic status led to lower power developed during short-term maximal exercises.