Effect of chronic hypoxia and socioeconomic status on VO2 max and anaerobic power of bolivian boys

Abstract

Abstract. The aim of this work was to analyze the effects of altitude and socioeconomic and nutritional status on maximal oxygen uptake (Vo₂max) and anaerobic power (P) in 11-yr-old Bolivian boys. At both high (HA) (3,600 m) and low (LA) (420 m) altitudes, the boys were divided into high (HA₁, n = 23, LA₁, n = 23, LA₁, n = 48) and Iow (HA₂, n = 44,LA₂, n = 30) socioeconomic levels. Anthropometric characteristics, Vo₂max, and P [maximal P (Pmax) during a force-velocity test and mean P (P) during a 30-s Wingate test] were measured. Results showed that 1) anthropometric parameters were not different between HA₁ and LA₁ and HA₂, and LA₂ boys, but HA₂ and LA₂ boys were two years behind HA₁ and LA₁ boys in development; 2) Vo₂max was not different in boys from the same altitude, but at HA Vo₂max was 10% Iower than at LA (HA₁ = 37.2 + - 5.6, HA₂ = 38.9 + - 6.4, LA₁ = 42.5 + 5.8, LA₂ = 42.5 + - 5.3 ml .min-1.kg-' body wt); and 3) Pmax and P were higher in well-nourished than in undernourished boys, but there was no difference in Pmax and P between HA₁ and LA₁ and HA₂ and LA₂ boys (HA₁ = 6.8 + - 1.0, HA₂ = 5.5 + - 0.8, LA₁ = 7.1 + - 1.0, LA₂ = 5.3 + - 0.9 W/kg for Pmax; HA₁ = 5 .2 + - 0.8, HA₂ = 4.5 + - 0.9, LA₁ = 5.2 + - 0.7, LA₂ = 4.0 + - 0.6 W/kg for P). A marginal state of malnutrition had no effect on Vo₂max but led to lower P in prepubertal children at HA as well as at LA.