French title

The main objectives of this study were: (1) to test the effect of performance level on the maximum lipids oxidation flow rate (LIPOXmax) in trained cyclists, and (2) to identify the target exercise intensities corresponding to LIPOXmax. Twenty-four trained cyclists were distributed in two groups according to their performance level (G1: 17 cyclists with local level versus G2: seven cyclists with elite level). All cyclists performed the same exercise test. Cardiorespiratory data and rating of perceived exertion (RPE) were measured during each stage. LIPOXmax was determined, and then expressed in terms of percentage of maximal aerobic power (MAP), maximal oxygen uptake ( V Ee[tm] O 2 max ), reserve oxygen uptake ( V Ee[tm] O 2 r e serve ), maximal heart rate (HRmax), reserve heart rate (HRreserve), and RPE. These values were compared from one-way ANOVA (G1 versus G2). Confidence intervals (CI95%) of LIPOXmax corresponded to 37-44% MAP, 41-47% V Ee[tm] O 2 max , 35-42% V Ee[tm] O 2 r e serve , 44-59% HRreserve, and to RPE 8-10, independently of group (p >0.05). However, group effect was noticed when LIPOXmax was expressed in terms of HRmax (CI95%=56-61% and 60-70% HRmax for G1 and G2, respectively; p =0.03). However, a large part of the interindividual variation of LIPOXmax was noticed. The performance level do not influence the LIPOXmax in trained cyclists (except if it is expressed in % HRmax). It seems difficult to use common target exercise intensities in order to prescribe exercise intensity corresponding to LIPOXmax in trained cyclists.Original Abstract: Les objectifs etaient d'examiner l'influence du niveau de performance sur le point d'oxydation maximale des lipides (Lipoxmax) chez des cyclistes, et d'identifier les zones d'intensites cibles correspondantes au Lipoxmax. Vingt-quatre cyclistes entraA registered nes etaient repartis en deux groupes en fonction de leur niveau de performance en cyclisme (G1: 17aacyclistes de niveau departemental A regional versus G2: sept cyclistes elites ou professionnels). Tous les cyclistes (G1aaet G2) realisaient un m(TM)me test de calorimetrie d'effort, durant lequel les parametres cardiorespiratoires et la perception de l'effort (RPE) etaient mesures. Le Lipoxmax etait identifie, puis exprime sous la forme d'un pourcentage de la puissance maximale aerobie (PMA), de la consommation maximale d'oxygene ( V Ee[tm] O 2 max ), de la consommation d'oxygene de reserve ( V Ee[tm] O 2 r e serve ), de la frequence cardiaque ma