Marginal malnutrition in school-aged Colombian boys: body composition and maximal O2 consumption

Do changes in body composition account for the changes in O2 consumption during maximal exercise (VO2max) in nutritionally deprived boys? School age urban and rural boys with no deficits (N) or with significant deficits (W-H) in weight for age and for height were studied. Percentage lean body mass was higher in W-H than in N boys. By contrast percentage intracellular water, the creatinine excretion coefficient and percentage arm muscle mass were not higher in W-H boys. Thus nutritional compromise decreased more the cellular than the support tissues of the body. VO2max per unit body weight was higher in W-H than in N boys. In the rural group, this was accounted for by the higher percentage lean body mass in W-H boys. In the urban group, VO2max/lean body mass was also higher in most W-H boys. Thus W-H urban boys had higher levels of aerobic training than N urban boys, reflecting perhaps a relative increase in daily physical activity as the same tasks have to be performed with less muscle by W-H boys.