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 (RRT), against which the fit of an existing W' balance (W') prediction model was tested. Methods Twenty active adults, consisting of trained cyclists (n = 9; age 43 ± 15 years; V̇O 61.9 ± 8.5 mL∙kg∙min) and untrained (n = 11; age 36 ± 15 years; V̇O 52.4 ± 5.8 mL∙kg∙min) performed two tests 2-4 days apart, consisting of three incremental ramps (20 W∙min) to exhaustion interspersed with 2-min recoveries. Results Intra-trial differences between recoveries demonstrated significant reductions in the amount of W' reconstituted for the group and both sub-sets (p < 0.05). 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. Inter-trial relative reliability of W' reconstitution was evaluated by intraclass correlation coefficients for the group (≥ 0.859); trained (≥ 0.940) and untrained (≥ 0.768) sub-sets. 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' prediction models. Furthermore, the W' model did not provide a good fit for the RRT, which itself proved to be a reliable test protocol.

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 (∆W′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, ∆W′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.

Purpose The aim of this study was to investigate the individual $$W^{^{\prime}}$$ W ′ reconstitution kinetics of trained cyclists following repeated bouts of incremental ramp exercise, and to determine an optimal mathematical model to describe $$W^{^{\prime}}$$ W ′ reconstitution. Methods Ten trained cyclists (age 41 ± 10 years; mass 73.4 ± 9.9 kg; $$\dot{V}{\text{O}}_{2\max }$$ V ˙ O 2 max 58.6 ± 7.1 mL kg min−1) completed three incremental ramps (20 W min−1) to the limit of tolerance with varying recovery durations (15–360 s) on 5–9 occasions. $$W^{^{\prime}}$$ W ′ reconstitution was measured following the first and second recovery periods against which mono-exponential and bi-exponential models were compared with adjusted R2 and bias-corrected Akaike information criterion (AICc). Results A bi-exponential model outperformed the mono-exponential model of $$W^{^{\prime}}$$ W ′ reconstitution (AICc 30.2 versus 72.2), fitting group mean data well (adjR2 = 0.999) for the first recovery when optimised with parameters of fast component (FC) amplitude = 50.67%; slow component (SC) amplitude = 49.33%; time constant (τ)FC = 21.5 s; τSC = 388 s. Following the second recovery, W′ reconstitution reduced by 9.1 ± 7.3%, at 180 s and 8.2 ± 9.8% at 240 s resulting in an increase in the modelled τSC to 716 s with τFC unchanged. Individual bi-exponential models also fit well (adjR2 = 0.978 ± 0.017) with large individual parameter variations (FC amplitude 47.7 ± 17.8%; first recovery: (τ)FC = 22.0 ± 11.8 s; (τ)SC = 377 ± 100 s; second recovery: (τ)FC = 16.3.0 ± 6.6 s; (τ)SC = 549 ± 226 s). Conclusions W′ reconstitution kinetics were best described by a bi-exponential model consisting of distinct fast and slow phases. The amplitudes of the FC and SC remained unchanged with repeated bouts, with a slowing of W′ reconstitution confined to an increase in the time constant of the slow component.

Objective: The purpose of this study was to establish the inter-day reliability of several performance variables measured during a 2 × 6 s sprint on a Wattbike cycle ergometer in male rugby players. Reliablilty was assessed against an 'analytical goal' of detecting meaningful changes that might be expected with fatigue in rugby. Design & Methods:Sixteen male rugby players performed three trials of the protocol on different days seperated by a mimimum of 48 h. The protocol comprised 2 × 6 s 'all out' cycle sprints with 90 s recovery between efforts. Typical error (TE), coefficient of variation (CV), smallest worthwhile change (SWC) and moderate change (MC) were calculated between each trial for seven variables.Results: Peak Power output significantly increased from the first to the third trial (3.3-4.4 %), whilst all variables had better reliability from trials 2-3 than 1-2. Mean power (3.7%), peak power (4.2%) and total distance (2.7%) had a CV% lower than decrements observed with team sport fatigue (~5%), however only total work had a TE (2.1 kJ) lower than the smallest worthwhile change (4.6 kJ) while the remainder were lower than the moderate worthwhile change. Conclusion:Assuming one complete habituation trial is completed, total work appears to be the most reliable variable capable of detecting a worthwhile change in performance. We recommend using this variable to monitor fatigue in rugby players.(Journal of Trainology 2018;7:1-4)

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