Prior Upper Body Exercise Impairs 4-km Cycling Time-Trial Performance Without Altering Neuromuscular Function

Author(s)

Bertuzzi, Romulo ^[1] ; Silva-Cavalcante, Marcos D. ^{[1, 2]} ; Couto, Patricia Guimaraes ^[1] ; Azevedo, Rafael de Almeida ^[1] ; Coelho, Daniel Boari ^[3] ; Zagatto, Alessandro ^[4] ; Lima-Silva, Adriano Eduardo ^{[2, 5]} ; Millet, Guillaume Y. ^[6]

Affiliation

^[1] Univ Sao Paulo, Sao Paulo - Brazil

^[2] Univ Fed Pernambuco, Recife, PE - Brazil

^[3] Fed Univ ABC, Santo Andre, SP - Brazil

^[4] Paulista State Univ Unesp, Sao Paulo - Brazil

^[5] Technol Fed Univ Parana, Curitiba, Parana - Brazil

^[6] Univ Calgary, Calgary, AB - Canada

• Document type: Journal article
• Source: RESEARCH QUARTERLY FOR EXERCISE AND SPORT; v. 92, n. 1 FEB 2020.
• Web of Science Citations: 1

Abstract

Purpose: This study investigated the effects of previous exhaustive upper body exercise on performance and neuromuscular fatigue following a 4-km cycling time-trial (4-km TT). Methods: Eight recreational cyclists performed a 4-km TT with (ARM(PRE)) or without (CONTR) a previous arm-crank maximal incremental test. In each experimental session, neuromuscular fatigue was evaluated with a series of electrically evoked and maximal voluntary isometric contractions (MVC). Oxygen uptake (O-2), heart rate, electromyographic muscle activity (EMG(RMS)) and rating of perceived exertion (RPE) were also recorded throughout the 4-km TT. Results: The average power output during the 4-km TT was reduced (P = .027) for the ARM(PRE) (299 +/- 59 W) group, compared with CONTR (310 +/- 59 W) and overall performance in 4-km TT was impaired (P = .021) in ARM(PRE) (382 +/- 28 s) compared with CONTR (376 +/- 27 s). The decrease observed in MVC (P = .033) and potentiated peak twitch force (P = .004) at post-TT were similar between the ARM(PRE) and CONTR conditions (P = .739 and P = .493, respectively). There was no (P = .619) change in voluntary activation at post-TT between conditions. O-2, EMG(RMS) and RPE measured throughout the 4-km TT were not significantly different between the conditions (P = .558, P = .558 and P = .940, respectively). The rate of RPE change relative to power output average and heart rate was higher (P = .030 and P = .013, respectively) in ARM(PRE) (0.031 +/- 0.018 AU/W and 168 +/- 8 bpm) than CONTR (0.022 +/- 0.010 AU/W and 161 +/- 7 bpm). Conclusion: These results suggest that impaired performance in ARM(PRE) was mostly due to pronounced perception of effort rather than neuromuscular fatigue. (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