Comparison of two methods of cardiopulmonary exercise testing for assessing physical fitness in children and adolescents with extreme obesity.

It is well-known that children and adolescents with obesity have increased over recent decades which in turn carries greater risk of co-morbidities and poses a preventive as well as a therapeutic challenge. Currently, there are limited recommendations available on proven methods for recording physical fitness in children and adolescents presenting with extreme obesity. In this study, twenty participants, aged 12-17 years, with a body mass index (BMI) above the 99.5th percentile, were comparatively assessed, using a correlation between their physical fitness on a bicycle (BC) and treadmill (TM) cardiopulmonary exercise testing (CPET) with a lactate diagnostic. The results of the BC and the TM were as follows: maximum heart rate (HRmax) 186.4 ± 8.6 beats per minute (bpm) vs. 190.8 ± 8.8 bpm, peak oxygen consumption (VO2peak/kg) 23.5 ± 2.9 ml/min/kg vs. 25.4 ± 3.1 ml/min/kg, and maximum lactate (Lamax) 6.4 ± 1.6 mmol/l vs. 5.6 ± 1.4 mmol/l. The values of HRmax and VO2peak/kg were significantly higher for adolescents tested on the TM. However, no significant difference was observed in either Lamax values or between the genders.    Conclusions: The higher values of HRmax and VO2peak/kg could be attributed to the activation of a higher percentage of muscle mass on the TM. Lower Lamax values on the TM suggest maximum physical exertion was not achieved. This could be due to the extreme body weight carried by the participants. Both the BC and the TM CPET could be used for assessing physical fitness in children and adolescents with extreme obesity but should not be used interchangeably. What is Known: • Currently, there are only limited recommendations available on proven methods for recording physical fitness in children and adolescents with extreme obesity available. What is New: • Cardiopulmonary exercise testing with maximum physical exertion has been shown to be feasible in children and adolescents with extreme obesity. The results obtained from this study demonstrated that both a bicycle and a treadmill can be effectively used for assessing the physical fitness levels in children and adolescents with extreme obesity.