Crossover and maximal fat oxidation points during running and cycling in sedentary subjects

Abstract

Summary Objective The purpose of this study was to compare crossover and maximal fat oxidation points during cycling and running in healthy participants. Methods Maximal oxygen uptake V ˙ O 2 max , maximal aerobic power (MAP) and maximal aerobic velocity (MAV) were assessed in 12 sedentary participants (aged 20.5 ± 1.0 years), using a maximal progressive tests on a cycle ergometer and on a treadmill. Participants performed in random sequence, two submaximal graded exercise tests on a cycle ergometer (CE) and on a treadmill (TM), based on the measured MAP and MAV respectively. Respiratory parameters, the crossover (COP) and the maximal fat oxidation points (LIPOXmax) were measured during these submaximal protocols. Results There were no significant mean (±SD) differences in COP (CE: 46.4 ± 4.9%, TM: 47.4 ± 3.7%; P = 0.36) and in LIPOXmax (CE: 40.0 ± 7.4%, TM: 40.2 ± 2.1%; P = 0.92) expressed in percentage of V ˙ O 2 max between the two modes of exercise. The metabolic indices obtained on the CE and TM were significantly correlated (COP: r = 0.85; P Conclusion Our data show that COP and LIPOXmax measured during submaximal exercise (based on measured MAP or MAV) were not affected by the choice of ergometer. Both CE and TM yielded accurate and quiet similar metabolic indices that could be used to individualize training in healthy sedentary adults.