EFFECT OF CHRONIC HYPOXIA AND SOCIOECONOMIC-STATUS ON ANAEROBIC POWEROF 10-YEAR-OLD TO 12-YEAR-OLD BOLIVIAN BOYS

The aim of this study was to analyze the effect of chronic high altitu de 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 Pat (3600 m, Bolivia); 23 were from a high socioeconomic background (HAHSE S) and 44 from a low socioeconomic background (HALSES). The group stud ied at low altitude in Santa Cruz de la Sierra (420 m, Bolivia) consis ted of 78 boys of the same age; 30 were from a high (LAHSES) and 48 fr om a low (LALSES) socioeconomic background. Maximal anaerobic power (P max) 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 hi gh and low altitude on the same calibrated cycle ergometer. At both hi gh and low altitudes, Pmax expressed in absolute terms or relative to body weight were significantly higher in boys of high socioeconomic st atus (HAHSES: 6.8 +/- 1.0; LAHSES: 7.1 +/- 1.0 W.kg(-1) BW) than in bo ys 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 high land and lowland boys of the same socioeconomic class. The same observ ations were obtained for P (HAHSES: 5.2+/-0.8; HALSES: 4.5+/-0.9; LAHS ES: 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 anaerob ic power. However, regardless of altitude, low socioeconomic status le d to lower power developed during short-term maximal exercises.