Cardiorespiratory fitness of obese boys.

Childhood obesity is increasing worldwide and may be linked to coronary heart diseases that appear later in life but its risk related behaviour patterns are evident during childhood and adolescence. The present study aimed to evaluate the cardiorespiratory fitness in terms of maximum oxygen uptake (VO2max) in obese boys of West Bengal, India. Obese boys (N = 49) in the age range of 10-16 years were separated from their non-obese counterparts (N = 70) according to international age-wise cut off points of body mass index (BMI) and VO2max was evaluated by Queen's College Step Test (QCT). Lean body mass (LBM) was measured by skinfold method. Absolute VO2max was significantly higher (P<0.001) among obese boys because of higher values of body mass and LBM, which in turn exhibited significant correlation (r = 0.82 and r = 0.93, respectively; P<0.001) with VO2max. But VO2max per kg of body mass was significantly higher among non-obese boys but the VO2max per unit of body surface area was significantly higher (P<0.001) in obese group. VO2max is largely dependent on body mass and LBM whereas excessive fat mass imposes unfavourable burden on cardiac function and oxygen uptake by working muscles. This indicates that reduced oxygen utilization by adipose tissue during exercise reduces the overall VO2max.