European Journal of Applied Physiology

, Volume 113, Issue 4, pp 1091–1098

Sex differences in central and peripheral mechanisms of fatigue in cyclists

  • Beth W. Glace
  • Ian J. Kremenic
  • Malachy P. McHugh
Original Article

DOI: 10.1007/s00421-012-2516-4

Cite this article as:
Glace, B.W., Kremenic, I.J. & McHugh, M.P. Eur J Appl Physiol (2013) 113: 1091. doi:10.1007/s00421-012-2516-4

Abstract

We examined peripheral versus central contributions to fatigue in men and women during prolonged cycling using a peripheral nerve magnetic stimulation-based technique. 11 men (41 ± 3 years) and 9 women (38 ± 2 years) cycled for 2 h at ventilatory threshold with 5, 1-min sprints interspersed, followed by a 3-km time trial. Quadriceps strength testing was performed isometrically in a semi-reclined position pre- and post-cycling: (1) MVC; (2) MVC with superimposed 3-s magnetic stimulation to measure central activation ratio (CAR), a measure of central fatigue; (3) peripheral magnetic stimulation (PMS) alone of the femoral nerve in a 4-s pulse train, a measure of peripheral fatigue. Data were analyzed with mixed model ANOVA. When adjusted for body mass, men and women had similar strength (p = 0.876), and changes in MVC with time were similar between sexes, declining 22 % in men and 16 % in women (p = 0.360). CAR was similar between sexes and decreased 15 % (effect of time, p < 0.001). Changes in PMS-elicited force were different between sexes: only men lost stimulated strength (6.30 to 5.21 vs. 5.48 to 5.53 N kg−1, interaction p = 0.036). Results clearly demonstrate that quadriceps fatigue after >2 h of cycling was of both central and peripheral origin in men but solely due to central mechanisms in women.

Keywords

ExerciseGenderEnduranceNeuromuscular stimulation

Abbreviations

AUG

Voluntary contraction augmented with superimposed magnetic stimulation

CAR

Central activation ratio

MVC

Maximal voluntary contraction

PMS

Peripheral magnetic stimulation

RQ

Respiratory quotient

RPE

Rating of perceived exertion

VO2

Oxygen consumption

VOL

Voluntary contraction

VT

Ventilatory threshold

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Beth W. Glace
    • 1
  • Ian J. Kremenic
    • 1
  • Malachy P. McHugh
    • 1
  1. 1.Nicholas Institute of Sports Medicine and Athletic TraumaLenox Hill HospitalNew YorkUSA