Purpose: Aerobic training of professional road cyclists is linked to tremendous aerobic capacities that have never been clearly related to what occur in skeletal muscles submitted to a specific exercise. The aim of the present study was to examine specifically metabolic recovery after an incremental cycling exercise performed until exhaustion in professional road cyclists as compared with moderately trained subjects and so using 31P- MRS.
Methods: Subjects performed a progressive cycling exercise on a cycloergometer until exhaustion, then they were positioned back in the magnet (delay lower than 45 s) for recovery scanning. 31P spectra of thigh muscles were time averaged in 2-s blocks at rest and for 15 min throughout the recovery period.
Results: For a significantly more intense exercise (477 ± 28 vs 334 ± 24 W in controls; P < 0.001), professional road cyclists displayed similar end-of-exercise extrapolated pH values (6.43 ± 0.16 vs. 6.34 ± 0.05 in controls) and a significantly higher PCr concentration (20.1 ± 0.8 vs. 13.3 ± 0.5 mM in controls, P < 0.001). The pH recovery kinetics provided the evidence of metabolic adaptations related to a specific training in professional cyclists with a significantly faster rate (P < 0.01) of pH return toward basal values (32.8 ± 18.9 vs 10.8 ± 6.7 mM·min−1). On the contrary, no significant difference was measured for the PCr recovery kinetics. At rest, PDE concentration was significantly higher in professional cyclists (2.50 ± 0.80 vs 1.76 ± 0.42 mM), likely indicating a difference regarding fiber-type composition.
Discussion: The present data demonstrated for the first time that the tremendous aerobic capacity in professional cyclists is linked to faster pH recovery kinetics after a specific cycling exercise.
1Department of Sport Physiology, Faculty of Sport Sciences, IFR Marey, Marseille, FRANCE;2Laboratory of Respiratory Physiopathology, Faculty of Medicine, Marseille, FRANCE; and3Centre of Biological and Medical Magnetic Resonance, Faculty of Medicine, Marseille, FRANCE
Address for correspondence: Dr. François Hug, UPRES EA 3285, Department of Sport Physiology, IFR Marey–Faculty of Sport Sciences, University of the Mediteranean (Aix-Marseille II), 163, avenue de Luminy, CC 910, 13288 Marseille Cedex 09, FRANCE; E-mail: email@example.com.
Submitted for publication September 2004.
Accepted for publication December 2004.
Fabrice Salanson—in memoriam.
Many thanks to the professional road cyclists and the sport science students who all gave their best during the various exercises of the protocol. Many thanks also to the team managers who strongly supported this experimental series (Cofidis, Bonjour, FDJeux.com, AG2R Prévoyance, and Crédit Agricole).
This study was supported by a grant from Amaury Sport Organisation (ASO-Société du Tour de France).