NON-INVASIVE PREDICTION OF AEROBIC CAPACITY IN PREPUBESCENT OBESE AND LEAN CHILDREN

Peak aerobic capacity is related not only to functional capacity but also to cardiovascular disease risk. The determination of peak aerobic capacity (peak oxygen consumption; VO2peak) involves an incremental exercise test to fatigue, which can be stressful for the person tested. The ability to predict VO2peak in children using a less stressful procedure would be useful for the clinician to assess functional capacity easily. Objective To determine if VO2peak can be accurately predicted from the determination of body composition by non-invasive dual x ray absorptiometry (DEXA). Methods VO2peak was determined in 16 prepubescent children (age 8–11 years) on a motorised treadmill using an incremental exercise test to volitional fatigue over 5–12 minutes. Oxygen consumption was determined using indirect calorimetry (Parvomedics metabolic cart). Body composition was determined using a whole-body DEXA (Hologic) scan over 10 minutes. Results VO2peak was 1.61 ± 0.1 litres/minute. Lean mass, fat mass, percentage body fat and minimum waist circumferences were 28.9 ± 13.29 kg, 16.76 ± 2.43 kg, 33.8 ± 2.6% and 73.2 ± 2.8 cm, respectively. VO2peak could be predicted from the following equation: VO2peak  =  −0.118 + (0.0000579 × lean mass) + (0.00000211 × fat mass), yielding a correlation coefficient of r  =  0.830 (p Conclusions The peak aerobic capacity of inactive prepubescent children can be accurately predicted equally well from either a non-invasive (DEXA) measurement of total body lean mass and total body fat mass or from a simple measurement of waist circumference.