Maximal lipidic power in high competitive level triathletes and cyclists

Objective: To describe the fat-oxidation rate in triathlon and different modalities of endurance cycling. Methods: 34 endurance athletes ( 15 male triathletes, 4 female triathletes, 11 road cyclists and 4 male mountain bikers) underwent a progressive cycloergometer test until exhaustion. Relative work intensity ( VO2max), minimal lactate concentration (La-min(-)), lactic threshold, individual lactic threshold (ILT), maximal fat-oxidation rate (Fat(max), Fat(max) zone) and minimal fat-oxidation rate (Fat(min)) were determined in each of the groups and were compared by means of one-way analysis of variance. Results: No significant differences were found for Fat(max), Fat(min) or for the Fat(max) zone expressed as fat oxidation rate (g/ min). Intensities -20%, -10% and -5% Fat(max) were significantly lower for mountain bikers with respect to road cyclists and female triathletes, expressed as % VO2max. Intensities 20%, 10% and 5% Fat(max) were significantly lower for mountain bikers with respect to male triathletes and female triathletes, and for male triathletes in comparison with female triathletes, expressed as % VO2max. Lactic threshold and La-min(-) did not show significant differences with respect to Fat(max). Lactic threshold was found at the same VO2max with respect to the higher part of the Fat(max) zone, and La-min(-) at the same VO2max with respect to the lower part of the Fat(max) zone. Conclusions: The VO2max of Fat(max) and the Fat(max) zone may explain the different endurance adaptations of the athletes according to their sporting discipline. Lactic threshold and La-min(-) were found at different relative work intensities with respect to those of Fat(max) even though they belonged to the Fat(max) zone.