Central alterations of neuromuscular function and feedback from group III-IV muscle afferents following exhaustive high-intensity one-leg dynamic exercise.
Fiche publication
Date publication
juin 2015
Journal
American journal of physiology. Regulatory, integrative and comparative physiology
Auteurs
Membres identifiés du Cancéropôle Est :
Pr LEPERS Romuald
Tous les auteurs :
Pageaux B, Angius L, Hopker JG, Lepers R, Marcora SM
Lien Pubmed
Résumé
The aims of this investigation were to describe the central alterations of neuromuscular function induced by exhaustive high-intensity one-leg dynamic exercise (OLDE, study 1) and to indirectly quantify feedback from group III-IV muscle afferents via muscle occlusion (MO, study 2) in healthy adult male humans. We hypothesized that these central alterations and their recovery are associated with changes in afferent feedback. Both studies consisted of two time-to-exhaustion tests at 85% peak power output. In study 1, voluntary activation level (VAL), M-wave, cervicomedullary motor evoked potential (CMEP), motor evoked potential (MEP), and MEP cortical silent period (CSP) of the knee extensor muscles were measured. In study 2, mean arterial pressure (MAP) and leg muscle pain were measured during MO. Measurements were performed preexercise, at exhaustion, and after 3 min recovery. Compared with preexercise values, VAL was lower at exhaustion (-13 ± 13%, P < 0.05) and after 3 min of recovery (-6 ± 6%, P = 0.05). CMEP area/M area was lower at exhaustion (-38 ± 13%, P < 0.01) and recovered after 3 min. MEP area/M area was higher at exhaustion (+25 ± 27%, P < 0.01) and after 3 min of recovery (+17 ± 20%, P < 0.01). CSP was higher (+19 ± 9%, P < 0.01) only at exhaustion and recovered after 3 min. Markers of afferent feedback (MAP and leg muscle pain during MO) were significantly higher only at exhaustion. These findings suggest that the alterations in spinal excitability and CSP induced by high-intensity OLDE are associated with an increase in afferent feedback at exhaustion, whereas central fatigue does not fully recover even when significant afferent feedback is no longer present.
Mots clés
Adult, Electric Stimulation, methods, Evoked Potentials, Motor, Exercise, Feedback, Physiological, Femoral Nerve, physiology, Humans, Lower Extremity, Male, Motor Cortex, physiology, Muscle Contraction, Muscle Fatigue, Muscle, Skeletal, innervation, Neurons, Afferent, physiology, Pain, physiopathology, Pain Perception, Pain Threshold, Physical Endurance, Refractory Period, Electrophysiological, Time Factors, Transcranial Magnetic Stimulation, Young Adult
Référence
Am. J. Physiol. Regul. Integr. Comp. Physiol.. 2015 Jun;308(12):R1008-20