Fat oxidation rates are higher during running compared with cycling over a wide range of intensities

• Published in: Metabolism, clinical and experimental Vol. 52; no. 6; pp. 747 - 752
• Main Authors: Achten, Juul, Venables, Michelle C, Jeukendrup, Asker E
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.06.2003; Elsevier
• Subjects: Adult; Bicycling - physiology; Biological and medical sciences; Chemical Phenomena; Chemistry; Cross-Over Studies; Exercise Test; Fundamental and applied biological sciences. Psychology; Heart Rate; Humans; Lipid Metabolism; Male; Mathematics; Oxidation-Reduction; Oxygen Consumption; Physical Endurance; Physical Exertion; Pulmonary Gas Exchange; Running - physiology; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Walking - physiology; Human; Treadmill exercise; Physical exercise; Stoichiometry; Maximum oxygen consumption; Bicycle ergometer; Male; Experimental study; Young adult; Fat; Oxidation; Gas exchange; Comparative study
• ISSN: 0026-0495; 1532-8600
• DOI: 10.1016/S0026-0495(03)00068-4

The aim of the present study was to compare the intensity that elicits maximal fat oxidation (Fatmax) determined using a cycle-ergometer and a treadmill-based protocol. Twelve moderately trained male subjects (66.9 ± 1.8 mL · kg−1 · min−1) performed 2 graded exercise tests to exhaustion. One test was performed on a cycle ergometer while 1 test was performed on a motorized treadmill; stage duration during both trials was 3 minutes. Gas exchange measurements and heart rate (HR) recordings were performed throughout exercise. Fat oxidation rates were calculated using stoichiometric equations. Maximal fat oxidation rates were significantly higher during running compared with cycling (0.65 ± 0.05 v 0.47 ± 0.05 g · min−1). However, the intensity, which elicited maximal fat oxidation, was not significantly different between the cycle ergometer and treadmill test (62.1 ± 3.1 v 59.2 ± 2.8% Vo2max, respectively). Fat oxidation rates were significantly higher during the treadmill test compared with the cycle ergometer test from 55 to 80%Vo2max. Maximal oxygen uptake and maximal HR were significantly higher during the treadmill test. It was concluded that fat oxidation rates were higher during walking compared with cycling. Maximal fat oxidation was 28% higher when walking compared with cycling, but the intensity, which elicits maximal fat oxidation, is not different between these 2 exercise modes.