Comparison of fat oxidation over a range of intensities during treadmill and cycling exercise in children

Abstract

Substrate metabolism differs between children and adults and is important for weight management during childhood. A direct comparison of fat oxidation over a range of exercise intensities and the estimation of Fatmax (exercise intensity that elicits maximal fat oxidation (MFO)) during treadmill (TM) and cycling exercise (CE) does not appear to be available in children. Fat oxidation and Fatmax were compared during TM and CE in 22 pre- to early pubertal children (9 girls and 13 boys). Fat oxidation was higher for TM compared with CE over a range of absolute and relative exercise intensities and this difference was more pronounced at higher intensities (P ≤ 0.05). Fat oxidation was higher in boys compared with girls at similar relative, but not absolute intensities (P ≤ 0.05). Fatmax was higher during TM compared with CE and higher in boys compared with girls (P ≤ 0.05). The 5% Fatmax zone (range of exercise intensities where fat oxidation was within 5% of MFO) spanned a wider range of intensities for TM compared with CE (P ≤ 0.05). Collectively, these findings suggest that exercise programmes aimed at promoting high rates of fat oxidation in pre- to early pubertal children should include TM rather than CE regardless of exercise intensity. Furthermore, Fatmax values indicate that brisk walking or slow running promotes MFO rates in this population.

Comparison of Substrate Oxidation and Energy Expenditure During Acute Aerobic Exercise With Moderate and High Intensity in Patients With Type 2 Diabetes

“…Some of the previous studies have not observed any significant difference between diabetic subjects and obese subject in substrate oxidation rate, which differ from the results of this study (38)(39)(40). The reason of this difference can be related to the type of exercise protocol and its intensity.…”

Measurement and Physiological Relevance of the Maximal Lipid Oxidation Rate During Exercise (LIPOXmax)

“…previous exercise performed just before the exercise calorimetry MFO slightly increased (Chenevière et al, 2009a) puberty LIPOXmax and MFO are higher in prepubertal children and gradually decrease throughout puberty to reach adult values at the end of puberty (Brandou et al, 2006b;Riddell et al, 2008 ;(Zakrzewski & Tolfrey, 2011b (Friedlander et al, 1998a(Friedlander et al, , 1998bChenevière et al, 2011 ;Brun et al, 2009a ;Zakrzewski & Tolfrey, 2011b .…”

Assessment of maximal fat oxidation during exercise: A systematic review

“…The findings obtained are not conclusive. While two studies reported greater MFO during walking/ running on a treadmill than cycling on a cyclo-ergometer in healthy and moderately trained men with ~23 years of age (0.65 ± 0.05 vs 0.47 ± 0.05 g/min) 29 and in children aged from 8 to 13 (0.24 ± 0.06 vs 0.19 ± 0.05 g/min), 38 two other studies did not find significant differences in moderately trained individuals of both sexes aged ~29 (0.48 ± 0.04 vs 0.44 ± 0.05 g/min) 32 and in healthy men and women aged 22-29 (0.50 ± 0.19 vs 0.47 ± 0.22 g/min). 35 Furthermore, different results have been obtained when comparing treadmill vs cyclo-ergometer graded exercise protocols in Fat max across populations with different biological characteristics.…”