Changes in peak fat oxidation in response to different doses of endurance training

TY - JOUR

T1 - Changes in peak fat oxidation in response to different doses of endurance training

AU - Larsen, Mads Rosenkilde

AU - Reichkendler, M H

AU - Auerbach, P

AU - Bonne, Thomas Christian

AU - Sjödin, Anders Mikael

AU - Ploug, Thorkil

AU - Stallknecht, B M

N1 - CURIS 2015 NEXS 044

PY - 2015/2/1

Y1 - 2015/2/1

N2 - The effect of different doses of endurance training on the capacity to oxidize fat during exercise in sedentary, overweight men and assessment of variables associated with changes in peak fat oxidation (PFO) were evaluated. Young, sedentary, overweight men were randomized to either the high-dose (HIGH, 600kcal/day, n=17) or moderate-dose (MOD, 300kcal/day, n=18) endurance training groups or controls (CON, n=15). PFO and peak oxygen uptake (VO2 peak) were measured using indirect calorimetry, body composition using dual-energy x-ray absorptiometry, and protein levels of mitochondrial enzymes determined by Western blotting. PFO increased in both MOD [1.2mg/kg fat-free mass (FFM)/min, 95% confidence interval (CI): 0.08:2.3, P=0.03] and HIGH (1.8mg/kg FFM/min, CI: 0.6:2.9, P<0.001) compared with CON. Skeletal muscle expression of citrate synthase, β-hydroxyacyl-CoA dehydrogenase, and mitochondrial oxphos complexes II-V increased similarly in MOD and HIGH. Stepwise multiple linear regression analysis with backward elimination of individual variables correlated with changes in PFO revealed increases in cycling efficiency, FFM, and VO2 peak as the remaining associated variables. In conclusion, PFO during exercise increased with both moderate- and high-dose endurance training. Increases in PFO were mainly predicted by changes in VO2 peak, FFM, and cycling efficiency, and less with skeletal muscle mitochondrial enzymes.

AB - The effect of different doses of endurance training on the capacity to oxidize fat during exercise in sedentary, overweight men and assessment of variables associated with changes in peak fat oxidation (PFO) were evaluated. Young, sedentary, overweight men were randomized to either the high-dose (HIGH, 600kcal/day, n=17) or moderate-dose (MOD, 300kcal/day, n=18) endurance training groups or controls (CON, n=15). PFO and peak oxygen uptake (VO2 peak) were measured using indirect calorimetry, body composition using dual-energy x-ray absorptiometry, and protein levels of mitochondrial enzymes determined by Western blotting. PFO increased in both MOD [1.2mg/kg fat-free mass (FFM)/min, 95% confidence interval (CI): 0.08:2.3, P=0.03] and HIGH (1.8mg/kg FFM/min, CI: 0.6:2.9, P<0.001) compared with CON. Skeletal muscle expression of citrate synthase, β-hydroxyacyl-CoA dehydrogenase, and mitochondrial oxphos complexes II-V increased similarly in MOD and HIGH. Stepwise multiple linear regression analysis with backward elimination of individual variables correlated with changes in PFO revealed increases in cycling efficiency, FFM, and VO2 peak as the remaining associated variables. In conclusion, PFO during exercise increased with both moderate- and high-dose endurance training. Increases in PFO were mainly predicted by changes in VO2 peak, FFM, and cycling efficiency, and less with skeletal muscle mitochondrial enzymes.

U2 - 10.1111/sms.12151

DO - 10.1111/sms.12151

M3 - Journal article

C2 - 24350597

SN - 0905-7188

VL - 25

SP - 41

EP - 52

JO - Scandinavian Journal of Medicine & Science in Sports

JF - Scandinavian Journal of Medicine & Science in Sports

IS - 1

ER -