Regression‐based prediction of net energy expenditure in children performing activities at high altitude

Abstract

We developed a simple, non-invasive, and affordable method for estimating net energy expenditure (EE) in children performing activities at high altitude. A regression-based method predicts net oxygen consumption (VO(2)) from net heart rate (HR) along with several covariates. The method is atypical in that, the "net" measures are taken as the difference between exercise and resting VO(2) (DeltaVO(2)) and the difference between exercise and resting HR (DeltaHR); DeltaVO(2) partially corrects for resting metabolic rate and for posture, and DeltaHR controls for inter-individual variation in physiology and for posture. Twenty children between 8 and 13 years of age, born and raised in La Paz, Bolivia (altitude 3,600m), made up the reference sample. Anthropometric measures were taken, and VO(2) was assessed while the children performed graded exercise tests on a cycle ergometer. A repeated-measures prediction equation was developed, and maximum likelihood estimates of parameters were found from 75 observations on 20 children. The final model included the variables DeltaHR, DeltaHR(2), weight, and sex. The effectiveness of the method was established using leave-one-out cross-validation, yielding a prediction error rate of 0.126 for a mean DeltaVO(2) of 0.693 (SD 0.315). The correlation between the predicted and measured DeltaVO(2) was r = 0.917, suggesting that a useful prediction equation can be produced using paired VO(2) and HR measurements on a relatively small reference sample. The resulting prediction equation can be used for estimating EE from HR in free-living children performing habitual activities in the Bolivian Andes.

Combined effect of body position, apparatus and distraction on children's resting metabolic rate

“…RMR measurements have been conducted predominantly to determine dietary requirements and to inform dietary or physical activity prescriptions. Further, RMR measurements have been used to calculate ( exercise minus rest) with applicability in a large range of studies 20–25. In a study of adults in our laboratory we have shown that different indirect calorimetry systems, such as ventilated hood and mouthpiece and nose‐clip, can result in significant differences in RMR and VO 2net measures 17.…”

The Determination of Changes in Body Heat Content during Exercise Using Calorimetry and Thermometry

“…The linear association between HR and Ṁ above the FLEX point is specific for each individual (Booyens and Hervey, 1960;Taylor et al, 1984) and is determined by a calibration trial typically performed on a cycle ergometer at 50 rpm with workloads increasing from 0 to 100 W in 25 W increments at 3 min intervals (Spurr et al, 1988). The values for Ṁ using this method have been demonstrated to correlate highly with those measured using indirect calorimetry during exercise in a number of subpopulations (Johnson et al, 2006;Leonard et al, 1995;Sarton-Miller et al, 2003;Spurr et al, 1988). Recently a more simplified HR method for the determination of Ṁ has been proposed without individual calibration that predicts Ṁ from age, weight, body fat percentage, sitting pulse rate and the exercise HR (Rennie et al, 2001).…”

Prediction of maximal aerobic capacity in severely burned children

“…[12][5] Okura and Tanaka established a method to predict VO 2 peak from the perceived exertion scale that can be applied not only in clinically normal people but also in patients with essential hypertension, through an easily applied procedure that’s does not require instrumentation. [5] However, the results of this study can be considered subjective rather than objective since it relies in the capacity of the patient to recognize general feelings of physical fatigue, cardiopulmonary system symptoms and tension in the exercising muscles and joints.…”

“…[5] Later in 2003, Sarton-Miller et al developed a non-invasive, and affordable regression-based method that predicts net oxygen consumption from net heart rate along with several covariates and is used for estimating net energy expenditure in children performing activities at high altitude. [12] However, heart rate can be affected by various drugs as beta- blocking agents and cardiac stimulants, and beta-adrenergic blockade with propranolol has been recognized as an efficacious therapy in the modulation of the heart response in burns [13–14], subsequently a method that uses heart rate alone to predict VO 2 peak should not be applied in these patients until further study is done. To our knowledge methods to predict VO 2 peak in burn children have not been previously described.…”