Fat oxidation kinetics is related to muscle deoxygenation kinetics during exercise

Zurbuchen, Anouck; Lanzi, Stefano; Voirol, Ludovic; Trindade, Cybele Barboza; Gojanovic, Boris; Kayser, Bengt; Bourdillon, Nicolas; Chenevière, Xavier; Malatesta, Davide

doi:10.3389/fphys.2020.00571

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Journal article

Fat oxidation kinetics is related to muscle deoxygenation kinetics during exercise

Zurbuchen, Anouck Department of Neurosciences and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
Lanzi, Stefano Institute of Sport Sciences of the University of Lausanne, Doctrine Selon Convention SSP-FBM, University of Lausanne, Lausanne, Switzerland - Division of Angiology, Heart and Vessel Department, Lausanne University Hospital, Lausanne, Switzerland
Voirol, Ludovic Institute of Sport Sciences of the University of Lausanne, Doctrine Selon Convention SSP-FBM, University of Lausanne, Lausanne, Switzerland
Trindade, Cybele Barboza Institute of Sport Sciences of the University of Lausanne, Doctrine Selon Convention SSP-FBM, University of Lausanne, Lausanne, Switzerland
Gojanovic, Boris Sports Medicine Unit, Swiss Olympic Medical Center, Department for Locomotion, Lausanne University Hospital, Lausanne, Switzerland
Kayser, Bengt Institute of Sport Sciences of the University of Lausanne, Doctrine Selon Convention SSP-FBM, University of Lausanne, Lausanne, Switzerland
Bourdillon, Nicolas Institute of Sport Sciences of the University of Lausanne, Doctrine Selon Convention SSP-FBM, University of Lausanne, Lausanne, Switzerland
Chenevière, Xavier Department of Neurosciences and Movement Science, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
Malatesta, Davide Institute of Sport Sciences of the University of Lausanne, Doctrine Selon Convention SSP-FBM, University of Lausanne, Lausanne, Switzerland

04.06.2020

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Frontiers in Physiology. - 2020, vol. 11, p. 571

English The present study aimed to determine whether whole-body fat oxidation and muscle deoxygenation kinetics parameters during exercise were related in individuals with different aerobic fitness levels.Methods: Eleven cyclists [peak oxygen uptake (V.O2peak): 64.9 ± 3.9 mL⋅kg–1⋅min–1] and 11 active individuals (V.O2peak: 49.1 ± 7.4 mL⋅kg–1⋅min–1) performed a maximal incremental cycling test to determine V.O2peak and a submaximal incremental cycling test to assess whole-body fat oxidation using indirect calorimetry and muscle deoxygenation kinetics of the vastus lateralis (VL) using near-infrared spectroscopy (NIRS). A sinusoidal (SIN) model was used to characterize fat oxidation kinetics and to determine the intensity (Fatmax) eliciting maximal fat oxidation (MFO). The muscle deoxygenation response was fitted with a double linear model. The slope of the first parts of the kinetics (a1) and the breakpoint ([HHb]BP) were determined.Results: MFO (p = 0.01) and absolute fat oxidation rates between 20 and 65% V.O2peak were higher in cyclists than in active participants (p < 0.05), while Fatmax occurred at a higher absolute exercise intensity (p = 0.01). a1 was lower in cyclists (p = 0.02) and [HHb]BP occurred at a higher absolute intensity (p < 0.001) than in active individuals. V.O2peak was strongly correlated with MFO, Fatmax, and [HHb]BP (r = 0.65–0.88, p ≤ 0.001). MFO and Fatmax were both correlated with [HHb]BP (r = 0.66, p = 0.01 and r = 0.68, p < 0.001, respectively) and tended to be negatively correlated with a1 (r = -0.41, p = 0.06 for both).Conclusion: This study showed that whole-body fat oxidation and muscle deoxygenation kinetics were both related to aerobic fitness and that a relationship between the two kinetics exists. Individuals with greater aerobic fitness may have a delayed reliance on glycolytic metabolism at higher exercise intensities because of a longer maintained balance between O2 delivery and consumption supporting higher fat oxidation rates.

Faculty

Faculté des sciences et de médecine

Department

Département de Médecine

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