Physiological and anthropometric determinants of critical power, W′ and the reconstitution of W′ in trained and untrained male cyclists

PURPOSE: This study examined the relationship of physiological and anthropometric characteristics with parameters of the critical power (CP) model, and in particular the reconstitution of W′ following successive bouts of maximal exercise, amongst trained and untrained cyclists. METHODS: Twenty male adults (trained nine; untrained 11; age 39 ± 15 year; mass 74.7 ± 8.7 kg; V̇O(2max) 58.0 ± 8.7 mL kg(−1) min(−1)) completed three incremental ramps (20 W min(−1)) to exhaustion interspersed with 2-min recoveries. Pearson’s correlation coefficients were used to assess relationships for W′ reconstitution after the first recovery (W′(rec1)), the delta in W′ reconstituted between recoveries (∆W′(rec))(,) CP and W′. RESULTS: CP was strongly related to V̇O(2max) for both trained (r = 0.82) and untrained participants (r = 0.71), whereas W′ was related to V̇O(2max) when both groups were considered together (r = 0.54). W′(rec1) was strongly related to V̇O(2max) for the trained (r = 0.81) but not untrained (r = 0.18); similarly, ∆W′(rec) was strongly related to V̇O(2max) (r = − 0.85) and CP (r = − 0.71) in the trained group only. CONCLUSIONS: Notable physiological relationships between parameters of aerobic fitness and the measurements of W′ reconstitution were observed, which differed among groups. The amount of W′ reconstitution and the maintenance of W′ reconstitution that occurred with repeated bouts of maximal exercise were found to be related to key measures of aerobic fitness such as CP and V̇O(2max). This data demonstrates that trained cyclists wishing to improve their rate of W′ reconstitution following repeated efforts should focus training on improving key aspects of aerobic fitness such as V̇O(2max) and CP.