Task failure during sustained low-intensity contraction is not associated with a critical amount of central fatigue

Autor: Guillaume Y. Millet, Djahid Kennouche, Robin Souron, Loïc Espeit, Thomas Lapole, Anne-Cloé Voirin, Thomas Rupp
Přispěvatelé: Université de Toulon (UTLN), Impact de l'Activité Physique sur la Santé (IAPS), Université de Nantes - UFR des Sciences et Techniques des Activités Physiques et Sportives (UFR STAPS), Université de Nantes (UN)
Rok vydání: 2020
Předmět:
Male
medicine.medical_specialty
Contraction (grammar)
medicine.medical_treatment
[SDV]Life Sciences [q-bio]
Physical Exertion
Pyramidal Tracts
Physical Therapy
Sports Therapy and Rehabilitation
Isometric exercise
030204 cardiovascular system & hematology
03 medical and health sciences
Young Adult
0302 clinical medicine
Voluntary contraction
Internal medicine
Isometric Contraction
Task Performance and Analysis
medicine
[SDV.MHEP.PHY]Life Sciences [q-bio]/Human health and pathology/Tissues and Organs [q-bio.TO]
Humans
Orthopedics and Sports Medicine
Knee
Evoked potential
ComputingMilieux_MISCELLANEOUS
Rating of perceived exertion
Knee extensors
business.industry
Electromyography
030229 sport sciences
Evoked Potentials
Motor
Transcranial Magnetic Stimulation
Electric Stimulation
Transcranial magnetic stimulation
Muscle Fatigue
Cardiology
Silent period
Perception
business
Femoral Nerve
Zdroj: Scandinavian Journal of Medicine and Science in Sports
Scandinavian Journal of Medicine and Science in Sports, Wiley, 2020, ⟨10.1111/sms.13815⟩
Scandinavian Journal of Medicine and Science in Sports, Wiley, 2020, 30 (12), pp.2329-2341. ⟨10.1111/sms.13815⟩
ISSN: 1600-0838
0905-7188
DOI: 10.1111/sms.13815⟩
Popis: Fatigue-related mechanisms induced by low-intensity prolonged contraction in lower limb muscles are currently unknown. This study investigated central fatigue kinetics in the knee extensors during a low-intensity sustained isometric contraction. Eleven subjects sustained a 10% maximal voluntary contraction (MVC) until task failure (TF) with neuromuscular evaluation every 3 minutes. Testing encompassed transcranial magnetic stimulation to evaluate maximal voluntary activation (VATMS ), motor evoked potential (MEP), and silent period (SP), and peripheral nerve stimulation to assess M-wave. Rating of perceived exertion (RPE) was also recorded. MVC progressively decreased up to 50% of the time to TF (ie, 50%TTF ) and then plateaued, reaching ~50% at TF (P < .001). VATMS progressively decreased up to 90%TTF and then plateaued, the decrease reaching ~20% at TF (P < .001). SP was lengthened early (ie, from 20%TTF ) during the exercise and then plateaued (P < .01). No changes were reported for MEP evoked during MVC (P = .87), while MEP evoked during submaximal contractions decreased early (ie, from 20%TTF ) during the exercise and then plateaued (P < .01). RPE increased linearly during the exercise to be almost maximal at TF. M-waves were not altered (P = .88). These findings confirm that TF is due to the subjects reaching their maximal perceived effort rather than any particular central event or neuromuscular limitations since MVC at TF was far from 10% of its original value. It is suggested that strategies minimizing RPE (eg, motivational self-talk) should be employed to enhance endurance performance.
Databáze: OpenAIRE
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