Abstract

Aim of this paper was to analyze the effects of chronic hypoxia and socioeconomic level on blood lactate concentrations obtained after maximal exercise and a 30-s Wingate test in 145 Bolivian boys (mean: 10.8 yr). Among the boys studied at high altitude (HA) (La Paz, 3600 m) and at low altitude (LA) (Santa Cruz de la Sierra, 420 m); 23 (HAHSES) and 48 (LAHSES) were from a high socioeconomic status (HSES), and 44 (HALSES) and 30 (LALSES) from a low socioeconomic status (LSES). Pubertal development was evaluated by salivary testosterone level (<T>). Blood samples were collected from the earlobe for blood lactate determination 2 min after cessation of maximal exercise (<L>v) and of a 30-s Wingate test (<L>w). Results showed: (1) <T> was significantly lower at HA. There was no significant difference between HAHSES and HALSES but LALSES was significantly lower than LAHSES. When the four groups were pooled, significant positive correlations between <L> and <T> were found; (2) for a same level of socioeconomic conditions, <L>v and <L>w were significantly lower at HA; (3) except for <L>v at HA, the HSES boys exhibited higher <L>v and <L>w than the LSES children for a same altitude; (4) there were significant linear relationships between the power developed during the 30-s Wingate test and <L>w. In conclusion, the lower <L> in HA vs LA and LSES vs HSES boys may be partly due to their lower gonadal maturation. However, other factors in regard to altitude and nutritional aspects are discussed. Verf.-Referat (gekuerzt)