Effects of prior high-intensity endurance exercise in subsequent 4-km cycling time trial performance and fatigue development

Author(s)

Azevedo, R. de Almeida ; Cruz, R. ; Couto, P. ; Silva-Cavalcante, M. D. ; Boari, D. ; Okuno, N. ; Lima-Silva, A. E. ; Bertuzzi, R.

• Document type: Journal article
• Source: SCIENCE & SPORTS; v. 37, n. 1, p. 11-pg., 2022-02-01.

Abstract

Objectives. - To investigate the effects of prior high-intensity endurance exercise on time trial (TT) performance and fatigue responses. Equipment and methods. - Eleven male cyclists visited the lab in two separate visits. The first visit was composed by a maximal cycling incremental test (MIT) followed by 15 min of passive rest before a 4-km cycling TT. The second visit (control, CON) was composed by moderate-intensity exercise for 5 min before the TT. Fatigue of knee extensors was assessed by isometric maximal voluntary contractions (IMVC), while the central (voluntary activation [VA]) and peripheral fatigue (peak torque of potentiated twitches [TwPt]) were evaluated using electrically-evoked contractions performed before and 1 min after the TT. Power output (PO), oxygen uptake ((V) over dotO(2)) and rating of perceived exertion (RPE) were recorded throughout the TT. Results. - TT performance (+2.6%) and average PO (+5.7%) improved in MIT compared to CON condition. While peripheral fatigue level was greater in MIT condition (P < 0.05), the central fatigue was lower compared to CON condition (P < 0.05). There were greater overall (V) over dotO(2) values (3.9 +/- 0.4 vs 3.6 +/- 0.4 L.min(-1)) but similar RPE responses (15 +/- 2 vs 15 +/- 3 a.u.) in MIT compared to CON. These findings indicate that prior high-intensity endurance exercise has positive effects in subsequent TT performance compare to moderate-intensity warm-up, despite exacerbated peripheral fatigue development. This response might be driven by greater aerobic reliance and exertion tolerance. (C) 2021 Elsevier Masson SAS. All rights reserved. (AU)

• FAPESP's process: 17/22053-0 - Pacing in cycling: a study about the neuromuscular fatigue and metabolic interface
• Grantee: Rômulo Cássio de Moraes Bertuzzi
• Support Opportunities: Regular Research Grants