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

W' in the extreme-intensity domain (W'EXT) was significantly smaller than W' in the severe-intensity domain (W'SVR).

• Twelve recreationally active participants (four females) completed three extreme-intensity and three severe-intensity constant-power output trials to establish the PO-duration series and obtain W' within their respective domains.
• The difference was statistically significant (P < 0.001).
• This finding suggests that the anaerobic work capacity available differs between the extreme and severe intensity domains.

Following task failure during extreme-intensity exercise (EXT1), additional work could be performed at severe-intensity (SVR3) until complete depletion of W'SVR.

• Participants completed two decremental protocols: from extreme-to-severe POs (EXT1→SVR3) and from severe-to-severe POs (SVR2→SVR3).
• There was no significant difference in W' between the composite EXT1→SVR3 and SVR2→SVR3 protocols compared to SVR3 alone (all P > 0.05).
• This indicates that W'EXT and W'SVR represent distinct and separable energy reserves, with W'SVR remaining largely intact after exhaustion in the extreme domain.

Heavy-intensity priming exercise increased both W'EXT and W'SVR by a similar magnitude.

• Participants completed one extreme- and one severe-intensity constant-PO trial each preceded by priming exercise (EXT1P and SVR2P, respectively), alongside control trials.
• The priming-induced increase in W'EXT and W'SVR was not statistically different from each other (P = 0.401).
• This suggests priming exercise has a comparable ergogenic effect on work capacity across both intensity domains.

Priming exercise increased peak physiological responses during extreme-intensity exercise, including V̇O2peak, peak minute ventilation (V̇Epeak), and peak blood lactate concentration ([La-]b-peak).

• V̇O2peak, V̇Epeak, and [La-]b-peak were all significantly greater in the primed extreme-intensity trial (EXT1P) compared to the unprimed control (EXT1) (all P < 0.05).
• This indicates that priming exercise elevated physiological ceiling values attained during extreme-intensity work.
• The elevated metabolic and ventilatory responses may partly explain the increase in W'EXT following priming.

The study design included constant-power output trials, decremental protocols, and priming exercise conditions across extreme and severe intensity domains to characterize W' and peak physiological responses.

• Twelve recreationally active participants (four females) completed a total of four protocol types.
• Protocol types included: (1) three extreme- and three severe-intensity constant-PO trials; (2) two decremental protocols (EXT1→SVR3 and SVR2→SVR3); (3) primed extreme- and severe-intensity trials (EXT1P and SVR2P); and (4) control extreme- and severe-intensity constant-PO trials.
• Peak values for V̇O2peak, [La-]b-peak, and V̇Epeak were analyzed across conditions.