The HALO submaximal treadmill protocol to measure cardiorespiratory fitness in obese children and youth: a proof of principle study

Many limitations exist with completing cardiorespiratory fitness testing in obese children. The aim of this study was to determine if the new Healthy Active Living and Obesity Research Group's (HALO's) submaximal cardiorespiratory fitness testing protocol for obese children and youth provides a comparable estimate of peak oxygen uptake to that measured using validated maximal and submaximal, equation-based protocols in the obese pediatric population. A group of obese children (n = 21; all ≥95th body mass index percentile; aged 10-17 years) completed 3 exercise testing protocols. Testing was completed as part of an ongoing cohort study and 2 submaximal cardiorespiratory fitness tests were completed, in randomized order, during a second visit. Significant correlations were found between observed peak oxygen uptake (mL·min(-1)) and predicted peak oxygen uptake for both the HALO (r = 0.75, p = 0.001) and Nemeth (r = 0.66, p = 0.001) submaximal protocols. A similar correlation was found, after accounting for body mass, between measured and predicted HALO peak oxygen uptake (mL·kg(-1)·min(-1)) values (r = 0.54, p = 0.01). HALO predicted peak oxygen uptake values showed a significant correlation when plotted against the measured values (r = 0.99). A Bland-Altman analysis found agreement between the maximal and HALO submaximal protocols (mean bias = -201.75 mL·min(-1)). The significant relationships found between estimates of peak oxygen uptake from the HALO submaximal protocol and measures of peak oxygen uptake during maximal cardiorespiratory testing support the use of the HALO submaximal protocol as a valid measure to estimate maximal cardiorespiratory fitness within the obese pediatric population. Given the proof of principle goal of this study, future research in the obese, pediatric population is encouraged to confirm the generalizability of the protocol.