Muscle fatigue in participants of indoor cycling

Abstract

Background: Indoor Cycling (IC) has been gaining recognition and popularity within recent years and few studies have investigated its benefits for sedentary participants.

Objective: The aim of this study was to evaluate differences in the surface electromyography (sEMG) variables, heart rate (HR), and subjective effort in sedentary participants while they performed an IC session and to compare their results with the trained subjects, to answer the question: Are trained cyclists less susceptible to muscle fatigue, since it is expected that they make less effort?

Design: Twenty-six volunteers were split into two groups according to their fitness status and weekly training load. Each participant completed an IC session in a private gym, lasting 45 minutes and were encouraged to follow the pedaling frequency and cycle resistance, within their limitations. Main Outcome Measures: HR, participants' subjective effort on the Borg Scale of Perceived Exertion (Borg Scale) and sEMG data were compared between groups.

Results: 28.6% of the sedentary participants withdrew from the study. Exercise intensity, assessed using the HR, was similar in both groups. The subjective perceived effort, assessed using the Borg Scale, was significantly higher in the sedentary group. All muscles considered in the sedentary group had higher variation levels of Root Mean Square (RMS) and Median Frequency (MF) than those in the trained group.

Conclusion: Sedentary participants are more likely to present fatigue and IC can be incorporated into protocols for this population, but their fitness levels should be taken into account because each performance depends on the individual's physical fitness.

Level of evidence: IIIb.

Keywords: cycling; muscle fatigue; surface electromyography.

Figure 1.

RMS (% MLP) and MF (Hz) variation during the IC session in trained and sedentary groups. ^*p< 0.05 group effect.

Figure 2.

Summary of RMS and MF percentages in the lower quadrants of JASA plot, for muscles in both groups. GM: gluteus maximum; ST: semitendinosus; BF: biceps femoris; RF: rectus femoris.