Human Performance Across the Extreme- and Severe-Intensity Domains: Insights from Decremental and Priming Exercise Protocols.

Abstract

Purpose: To investigate whether W' in the extreme-intensity domain is smaller, yet linked to the W' predicted by the severe-intensity time series.

Methods: Twelve recreationally active participants (four females) completed 1) three extreme-intensity and three severe-intensity constant-power output (PO) trials to establish the PO duration series and to obtain W' within their respective domains (W'EXT and W'SVR, respectively); 2) two decremental protocols from extreme-to-severe (EXT1→SVR3) and from severe-to-severe POs (SVR2→SVR3); 3) one extreme- and one severe-intensity constant-PO trial preceded by priming exercise (EXT1P and SVR2P, respectively); and 4) control extreme- and severe-intensity constant-PO trials. Peak values for oxygen uptake (V̇O2peak), blood lactate concentration ([La-]b-peak), and minute ventilation (V̇Epeak) were also analyzed.

Results: W'EXT was significantly smaller than W'SVR (P < 0.001). There was no difference in W' between the composite EXT1→SVR3 and SVR2→SVR3 and SVR3 alone (all P > 0.05). Priming-induced increase in W'EXT and W'SVR was not different (P = 0.401). V̇O2peak, V̇Epeak, and [La-]b-peak were all greater in EXT1P compared with EXT1 (all P < 0.05).

Conclusions: We showed that W'EXT is smaller than W'SVR during cycling. Following task failure during EXT1, more work could be performed at SVR3 until complete depletion of W'SVR. Additionally, heavy-intensity priming exercise increased W'EXT and W'SVR by a similar magnitude. Collectively, these findings suggest that performance within the extreme-intensity domain is limited by mechanisms, at least in part, different from those that limit performance within the severe-intensity domain.