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

      Chorley, Alan; Bott, Richard P; Marwood, Simon; Lamb, Kevin L; University of Chester (Springer, 2020-08-09)
      Abstract 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; V̇O2max 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 (ΔW′rec), CP and W′. Results CP was strongly related to V̇O2max for both trained (r = 0.82) and untrained participants (r = 0.71), whereas W′ was related to V̇O2max when both groups were considered together (r = 0.54). W′rec1 was strongly related to V̇O2max for the trained (r = 0.81) but not untrained (r = 0.18); similarly, ΔW′rec was strongly related to V̇O2max (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 V̇O2max. 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 V̇O2max and CP.
    • Slowing the Reconstitution of W′ in Recovery With Repeated Bouts of Maximal Exercise

      Chorley, Alan; Bott, Richard; Marwood, Simon; Lamb, Kevin L.; University of Chester; Liverpool Hope University (Human Kinetics, 2019-02-01)
      Purpose: This study examined the partial reconstitution of the work capacity above critical power (W′) following successive bouts of maximal exercise using a new repeated ramp test, against which the fit of an existing W′ balance (W'bal) prediction model was tested. Methods: Twenty active adults, consisting of trained cyclists (n = 9; age 43 [15] y, V˙ O2max 61.9 [8.5] mL·kg−1·min−1) and untrained cyclists (n = 11; age 36 [15] y, V˙ O2max 52.4 [5.8] mL·kg−1·min−1) performed 2 tests 2 to 4 d apart, consisting of 3 incremental ramps (20 W·min−1) to exhaustion interspersed with 2-min recoveries. Results: Intratrial differences between recoveries demonstrated significant reductions in the amount of W′ reconstituted for the group and both subsets (P < .05). The observed minimal detectable changes of 475 J (first recovery) and 368 J (second recovery) can be used to monitor changes in the rate of W′ reconstitution in individual trained cyclists. Intertrial relative reliability of W′ reconstitution was evaluated by intraclass correlation coefficients for the group (≥.859) and the trained (≥.940) and untrained (≥.768) subsets. Absolute reliability was evaluated with typical error (TE) and coefficient of variation (CV) for the group (TE ≤ 559 J, CV ≤ 9.2%), trained (TE ≤ 301 J, CV ≤ 4.7%), and untrained (TE ≤ 720 J, CV ≤ 12.4%). Conclusions: The reconstitution of W′ is subject to a fatiguing effect hitherto unaccounted for in W'bal prediction models. Furthermore, the W'bal model did not provide a good fit for the repeated ramp test, which itself proved to be a reliable test protocol.