Effect of aging on the performance factors in triathlon

This thesis is organized in three parts closely related, in order to observe the effect of aging on performance intriathlon, to the study the master triathlete model (i.e. > 40 years) through the performance factors and to measurethe impact of aging on the pedaling efficiency. The recruitment of master triathletes regularly trained in enduranceallowed the study of ageing, by controlling the cofounding effects of a sedentary lifestyle or pathologies appearance,on physiological systems. The decline in triathlon performance follows the exponential model. In male subjects,performance loss does not appear before 45 years, whereas in female, it appears earlier. Age-related declines inperformance were less pronounced for Olympic compared with the Ironman distance. There was a lesser age relateddecline in cycling performance compared with running and swimming performances. The second part of this thesisaimed to study the master triathlete model (maximal isometric torque and cardio-respiratory parameters) prior to andfollowing an Olympic distance triathlon. Prior to the event VO 2max, vVO2max, speed at ventilatory thresholds andrunning economy were significantly lower in master athletes, but maximal voluntary torque was similar betweengroups. 24h following the race, a similar significant decrease in VO 2max and vVO2max.was observed in both groups.No change was recorded in maximal voluntary torque or submaximal running economy following the event. Theresults indicate that for well trained subjects, the overall relative exercise intensity during an Olympic distancetriathlon and the fatigue effects of the race 24h after seems to be independent to the age. The last part of theexperimental work was to measure the impact of ageing on the pedaling efficiency in a population of cyclists andtriathletes all well trained on a wide age range. A significant decline was characterized. Explanatory hypotheses aremultifactorial. A relationship between energy efficiency and reduction of power or the modification of the bodycomposition with age has been established. Other assumptions are evoked as the remodeling of the pattern of muscleactivation and the expertise level of cycling, the mechanical properties of muscle or the share of the energy cost ofventilation.