TY - JOUR

T1 - Diurnal Variation of Maximal Fat-Oxidation Rate in Trained Male Athletes

AU - Amaro-Gahete, Francisco J.

AU - Jurado-Fasoli, Lucas

AU - Trivino, Alejandro R.

AU - Sanchez-Delgado, Guillermo

AU - De-la-O, Alejandro

AU - Helge, Jorn W.

AU - Ruiz, Jonatan R.

PY - 2019

Y1 - 2019

N2 - Purpose: To analyze the diurnal variation of maximal fat oxidation (MFO) and the intensity that elicits MFO (Fat(max)) in trained male athletes. Methods: A total of 12 endurance-trained male athletes age 24.7 (4.1) y participated in the study. The authors measured MFO, Fat(max), maximum oxygen uptake (VO(2)max), and VO2 percentage at ventilatory threshold 2 with a graded exercise protocol performed on 2 days separated by 1 wk. One test was performed in the morning and the other in the afternoon. The authors assessed the participants' chronotype using the HOME questionnaire. Results: MFO and Fat(max) were greater in the afternoon than in the morning (Delta = 13%, P < .001 and Delta = 6%, P = .001, respectively), whereas there were similar VO(2)max and ventilatory threshold 2 in the morning, than in the afternoon test (Delta = 0.2%, P = .158 and Delta = 7%, P = .650, respectively). There was a strong positive association between VO(2)max and MFO in both morning and afternoon assessments (R-2 = .783, P = .001 and R-2 = .663, P < .001, respectively). Similarly, there was a positive association between VO(2)max and Fat(max) in both morning and afternoon assessments (R-2 = .406, P = .024 and R-2 = .414, P = .026, respectively). Conclusion: MFO and Fat(max) may partially explain some of the observed diurnal variation in the performance of endurance sports.

AB - Purpose: To analyze the diurnal variation of maximal fat oxidation (MFO) and the intensity that elicits MFO (Fat(max)) in trained male athletes. Methods: A total of 12 endurance-trained male athletes age 24.7 (4.1) y participated in the study. The authors measured MFO, Fat(max), maximum oxygen uptake (VO(2)max), and VO2 percentage at ventilatory threshold 2 with a graded exercise protocol performed on 2 days separated by 1 wk. One test was performed in the morning and the other in the afternoon. The authors assessed the participants' chronotype using the HOME questionnaire. Results: MFO and Fat(max) were greater in the afternoon than in the morning (Delta = 13%, P < .001 and Delta = 6%, P = .001, respectively), whereas there were similar VO(2)max and ventilatory threshold 2 in the morning, than in the afternoon test (Delta = 0.2%, P = .158 and Delta = 7%, P = .650, respectively). There was a strong positive association between VO(2)max and MFO in both morning and afternoon assessments (R-2 = .783, P = .001 and R-2 = .663, P < .001, respectively). Similarly, there was a positive association between VO(2)max and Fat(max) in both morning and afternoon assessments (R-2 = .406, P = .024 and R-2 = .414, P = .026, respectively). Conclusion: MFO and Fat(max) may partially explain some of the observed diurnal variation in the performance of endurance sports.

KW - Fat(max)

KW - VO(2)max

KW - circadian rhythm

KW - resistance

KW - fuel oxidation

U2 - 10.1123/ijspp.2018-0854

DO - 10.1123/ijspp.2018-0854

M3 - Journal article

C2 - 30702364

VL - 14

SP - 1140

EP - 1146

JO - International Journal of Sports Physiology and Performance

JF - International Journal of Sports Physiology and Performance

SN - 1555-0265

IS - 8

ER -