Anaerobic metabolism during pubertal development at high altitude.

In a previous study we showed that there were no differences in anaerobic metabolism between groups of 11-yr-old children living at high (3,700 m) and low (330 m) altitudes. The aim of this study is to investigate changes in this metabolism during pubertal development. We compare blood lactate concentration ([L]) after maximal bicycle exercise in 20 boys acclimatized to high altitude (HA, 12 yr old) and at low altitude in 14 boys (LA1, 12 yr old) and in 13 boys (LA2, 14 yr old). The subjects had the same level of physical fitness and the same nutritional and socioeconomic status. Pubertal development was identified by salivary testosterone concentration ([T]). Results (means +/- SE) showed 1) at the age of 12 years, [L] and [T] in HA were significantly higher than in LA1 ([L] was 9.2 +/- 0.5 vs. 6.8 +/- 0.5 mmol/l, [T] was 233 +/- 66 vs. 132 +/- 30 pmol/l), 2) [L] and [T] in HA were statistically the same as in LA2, and 3) a linear relationship between [L] and [T] was significant (P less than 0.05) in all HA and LA subjects. This suggests that the higher [L] in 12-yr-old boys living at HA could result in an enhanced anaerobic metabolism linked to an earlier gonadal maturation evaluated by testosterone level.