Maximal mechanical aerobic and anaerobic power output of low‐income Brazilian schoolchildren as a function of growth

Abstract

Maximal mechanical aerobic and anaerobic power outpout (POWER) on a cycle‐ergometer were measured in 131 children (60 girls and 71 boys) 8 and 9 years of age attending a public school in a low‐income area in Rio de Janeiro (RJ), Brazil. Deficits in stature were classified relative to American reference data (NCHS) to identify three groups of children: Group A, Z‐score of stature for age (S‐Age) ≥ 0 (no deficit); Group B, – 1 < Z S‐age < 0 (moderate deficits); and Group C, Z S‐age ≤ −1 (greatest deficit). A two‐way ANOVA with interaction was used to assess the influence of growth and sex on performance. There were no differences between sexes in anthropometric dimensions but boys had significantly greater estimated upper arm muscle + bone area than girls and also performed better on both tests. Deficits in stature negatively influenced (P < 0.05) aerobic and anaerobic function expressed in absolute values. However, when expressed in relation to body size, POWER and the anaerobic to aerobic ratio values were, in general, not significantly different among the groups. In conclusion, children living in underprivileged environments show deficits in growth, but appear to maintain a level of performance proportional to their smaller body size. From a practical point of view, however, the absolute functional capacity value may be more important, because under such underprivileged conditions, it is the total amount of work produced which determines work capacity in adult life and thus, may determine physical, economic, and social well‐being.