Maximal lipidic power in high competitive level triathletes and cyclists

To describe the fat-oxidation rate in triathlon and different modalities of endurance cycling.

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 (VO(2max)), 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.

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 % VO(2max). 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 % VO(2max). Lactic threshold and La(-)(min) did not show significant differences with respect to Fat(max). Lactic threshold was found at the same VO(2max) with respect to the higher part of the Fat(max) zone, and La(-)(min) at the same VO(2max) with respect to the lower part of the Fat(max) zone.

The VO(2max) 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.