Physical fitness of children resident at high altitude in Bolivia

Abstract

Abstract. 1) Maximal oxygen consumption (VO₂max) varies from 35 to 45 ml . min-1 . kg-1 and maximal heart rate from I88 to 194 beats . min-1. These values are lower than those of their counterparts at low altitude (LA) by 10-20% and 10 - 15b . min-1, respectively. 2) The anaerobic metabolism is not affected by chronic hypoxia if the nutritional conditions and pubertal development of HA and LA boys are the same. When related to percent of VO₂max, submaximal O₂ debts are similar at HA and LA. After supramaximal exercise, maximal O₂ debts (45.7 +- 2.7 vs 45.9 +- 3.8 mt . kg-1) and blood lactate concentrations (7.6 +- 0.6 vs 6.5 +- 0.6 mmol . 1-1) are also the same at HA and LA. No differences are observed between the 2 altitudes in ventilatory (60 vs 56% VO₂max) and lactate (60 vs 65% VO₂max) thresholds. The attitude of La Paz does not alter the anaerobic performance of a force-velocity test (from 6 to 10 W. kg-1) between the ages of 7 to 15 years but reduces by 14-17%" the mean anaerobic power developed during a 30-s Wingate test. This decrease could be linked to a lower participation of glycolysis and aerobic metabolism at HA during this test. 3) Poor socio-economic and nutritional conditions do not modify the aerobic performance of boys living in La Paz but lead to lower maximal anaerobic power (from - 17% to – 25% when compared with HA boys from a high sodio-economic background. 4) Finally, the altitude of La Paz does not change the development of aerobic and anaerobic metabolisms during puberty.