Muscle fatigue, pedalling technique and the slow component during cycling.

Keenan B MacDougall, Saied J Aboodarda, Paulina H Westergard, Brian R MacIntosh
Author Information
  1. Keenan B MacDougall: Faculty of Kinesiology, University of Calgary, Calgary, Canada.
  2. Saied J Aboodarda: Faculty of Kinesiology, University of Calgary, Calgary, Canada.
  3. Paulina H Westergard: Faculty of Kinesiology, University of Calgary, Calgary, Canada.
  4. Brian R MacIntosh: Faculty of Kinesiology, University of Calgary, Calgary, Canada.

Abstract

Above the first lactate threshold, the steady-state is delayed or prevented due to the slow component ( ). This phenomenon has been associated with muscle fatigue, but evidence for a causal relationship is equivocal. Moreover, little is known about the contribution of pedalling technique adjustments to during fatiguing cycling exercise. Eleven participants completed constant power trials at 10% above the second lactate threshold. Muscle fatigue was assessed, utilizing femoral nerve stimulation and instrumented pedals, while , quadriceps oxygenation, electromyography (EMG) and pedal force components were measured. Correlations between physiological and mechanical variables were estimated at group and individual levels. Group correlations revealed moderate values for with quadriceps twitch force (r = -0.51) and muscle oxygenation (r = -0.52), while weak correlations were observed for EMG amplitude (r = 0.26) and EMG mean power frequency (r = -0.16), and with pedalling mechanical variables such as peak total downstroke force (r = -0.16), minimum total upstroke force (r = -0.16) and upstroke index of effectiveness (r = 0.16). The findings here align with prior literature reporting significant correlations between the magnitude of muscle fatigue and that of , although there was large interindividual variability for all the reported correlations. Considering the heterogeneity in the data, it is difficult to determine the relative impact of pedalling technique adjustments on overall, but the present study opens the possibility that in some cases, increases in secondary to technical adjustments may be 'superimposed' on the underlying .

Keywords

References

  1. J Appl Physiol. 1972 Sep;33(3):351-6 [PMID: 5056210]
  2. Muscle Nerve. 2002 Mar;25(3):438-44 [PMID: 11870723]
  3. Exp Physiol. 2025 Jan;110(1):115-126 [PMID: 39412232]
  4. J Appl Physiol (1985). 1991 Dec;71(6):2099-106 [PMID: 1778898]
  5. J Physiol. 2011 Feb 1;589(Pt 3):727-39 [PMID: 21135050]
  6. Physiol Rep. 2021 Aug;9(16):e14951 [PMID: 34409753]
  7. Appl Physiol Nutr Metab. 2018 Sep;43(9):909-919 [PMID: 29566544]
  8. Front Physiol. 2016 Oct 13;7:463 [PMID: 27790156]
  9. Med Sci Sports Exerc. 2016 Nov;48(11):2228-2238 [PMID: 27015386]
  10. Exp Physiol. 2023 Mar;108(3):503-517 [PMID: 36648072]
  11. Eur J Appl Physiol. 2007 Apr;99(6):659-64 [PMID: 17226060]
  12. Sci Rep. 2020 May 7;10(1):7728 [PMID: 32382067]
  13. Med Sci Sports Exerc. 2009 Jun;41(6):1277-86 [PMID: 19461537]
  14. J Sports Sci. 2003 Mar;21(3):191-9 [PMID: 12703848]
  15. Eur J Appl Physiol Occup Physiol. 1986;55(3):229-35 [PMID: 3732250]
  16. J Sports Sci Med. 2012 Dec 01;11(4):759-67 [PMID: 24150089]
  17. Med Sci Sports Exerc. 1998 Aug;30(8):1270-5 [PMID: 9710868]
  18. Med Sci Sports Exerc. 2011 Nov;43(11):2046-62 [PMID: 21552162]
  19. Acta Physiol (Oxf). 2022 Feb;234(2):e13776 [PMID: 34985184]
  20. PLoS One. 2018 Jul 30;13(7):e0199794 [PMID: 30059543]
  21. J Appl Physiol (1985). 2011 Jun;110(6):1598-606 [PMID: 21415174]
  22. J Appl Physiol (1985). 1991 Oct;71(4):1245-60 [PMID: 1757346]
  23. Med Sci Sports Exerc. 2007 Jun;39(6):991-5 [PMID: 17545890]
  24. J Physiol. 2024 Sep;602(17):4113-4128 [PMID: 37606604]
  25. J Appl Physiol (1985). 2016 Aug 1;121(2):493-502 [PMID: 27339183]
  26. Med Sci Sports Exerc. 1994 Nov;26(11):1319-26 [PMID: 7741865]
  27. Anesth Analg. 2018 May;126(5):1763-1768 [PMID: 29481436]
  28. Eur J Sport Sci. 2024 Sep;24(9):1328-1340 [PMID: 39118274]

MeSH Term

Humans
Muscle Fatigue
Male
Bicycling
Oxygen Consumption
Adult
Muscle, Skeletal
Lactic Acid
Young Adult
Exercise Test

Chemicals

Lactic Acid

Word Cloud

Created with Highcharts 10.0.0r = -0fatiguepedallingforcecorrelations16muscletechniqueadjustmentscyclingEMGlactatethresholdslowcomponentpowerMusclequadricepsoxygenationelectromyographymechanicalvariablesr = 0totalupstrokefirststeady-statedelayedpreventedduephenomenonassociatedevidencecausalrelationshipequivocalMoreoverlittleknowncontributionfatiguingexerciseElevenparticipantscompletedconstanttrials10%secondassessedutilizingfemoralnervestimulationinstrumentedpedalspedalcomponentsmeasuredCorrelationsphysiologicalestimatedgroupindividuallevelsGrouprevealedmoderatevaluestwitch5152weakobservedamplitude26meanfrequencypeakdownstrokeminimumindexeffectivenessfindingsalignpriorliteraturereportingsignificantmagnitudealthoughlargeinterindividualvariabilityreportedConsideringheterogeneitydatadifficultdeterminethe relativeimpactoverallpresentstudyopenspossibilitycasesincreasessecondarytechnicalmay'superimposed'underlyingkineticsefficiencyenergeticsoxygenuptake

Similar Articles

Cited By