Acute downhill running does not induce fat oxidation
Eccentric exercise has been suggested for its potential to increase several health outcomes, including exercise-induced fat oxidation. Comparison of exercise intensity rather than exercise workload is required.
Thirteen moderately active young men (mean age, 24.6 ± 5.6 years; body mass index, 23.76 ± 3.24 kg/m2; maximal oxygen consumption (VO2max), 49.00 ± 3.19 ml/kg/min) performed two counterbalanced running sessions for 40 min at 60% VO2max, either running flat (Con-Exe) or running downhill at a gradient of − 12% (Ecc-Exe). The volumes of oxygen and carbon dioxide (VO2 and VCO2) were collected during exercise sessions, and fat oxidation was calculated.
There was no significant interaction between exercise condition and exercise duration (p > 0.05), and individual variations in fat oxidation during Con-Exe and Ecc-Exe were large and inconsistent.
Downhill running at 60% VO2max and inclination of − 12% does not induce fat oxidation.
KeywordsSubstrate oxidation Eccentric exercise Muscle contraction Respiratory exchange ratio
This is a research project that was supported by a grant from the research center for the sports science and physical activity, deanship of scientific research at King Saud University. The author thanks all participants, the Cardiovascular Laboratory and all research assistants, particularly Mr. Abdullah Al-Qawati.
Compliance with ethical standards
Conflict of interest
There is no conflict of interest to be disclosed.
Participants who expressed their interest in the study were asked to sign informed consent before commencing the study.
The study procedure was approved by the Institutional Review Board at King Saud University (IRB No. E-16-1831).
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