Effects of Endurance Training at the Crossover Point in Women With Metabolic Syndrome.
Résumé
Based on theoretical evidence, intensity at the crossover point (COP) of substrate utilization could be considered as potential exercise intensity for metabolic syndrome (MetS). This study aimed to examine the effects of a training program at COP on exercise capacity parameters in women with MetS and to compare two metabolic indices (COP and the maximal fat oxidation rate point LIPOXmax®) with ventilatory threshold (VT). Nineteen women with MetS volunteered to perform a 12-week training program on cycle ergometer, with an intensity corresponding to COP. Pre- and post-training values of anthropometric and exercise capacity parameters were compared in order to determine the effects of exercise training. The pre-post training change of COP, LIPOXmax® and VT were also investigated. After training, anthropometric parameters were significantly modified, with a reduction of body mass (3.0 ± 3.0%, p<0.001), fat mass (3.3 ± 3.4%, p<0.001) and body mass index (3.2 ± 3.4%, p<0.001). Exercise capacity was improved after the training program, with significant increase of maximal power output (25.0 ± 18.4%, p<0.001) and maximal oxygen uptake (VO2max = 9.0 ± 11.2%, p<0.01). Lastly, when expressed in terms of power output, COP, LIPOXmax® and VT occurred at a similar exercise intensity but the occurrence of these three indices is different when expressed in terms of oxygen uptake, heart rate or rating of perceived exertion. This study highlights the effectiveness of 12-week training program at COP to improve physical fitness in women with MetS. The relationships between metabolic indices and VT in terms of power output highlight the determination of VT from a shorter maximal exercise as a useful method for the determination of metabolic indices in MetS.