Transcranial magnetic stimulation (TMS) is a widely-used investigative technique in motor cortical evaluation. TMS is now being used in the investigation of fatigue to help partition the effects of central fatigue. Few studies have utilized this technique to evaluate the effects of locomotor exercise and none in conditions of extreme exercise. Therefore, the purpose of this thesis was twofold; first, to answer methodological questions pertaining to the use of TMS in fatigue evaluation, particularly of the quadriceps, and second, to investigate the effects of extreme exercise conditions on the development of central and supraspinal fatigue and corticospinal excitability and inhibition. In Studies 1 and 2, the effect of approaching a target force in different ways before the delivery a TMS pulse and the difference between commonly-employed methods of determining TMS intensity on the selection of optimal TMS intensity were investigated. In Study 3, the effect of one night sleep deprivation on cognitive and exercise performance and central parameters was investigated. The effect of a 110-km ultra-trail on the supraspinal component of central fatigue was evaluated in Study 4. The principal findings from this thesis are that during TMS evaluation during brief voluntary contractions, it is essential to deliver the TMS pulse once the force has stabilized at the target and that a stimulus-response curve at 20% MVC is appropriate for determining optimal TMS intensity in exercise and fatigue studies. Furthermore, while sleep deprivation negatively-impacted cognitive and exercise performance, it did not influence neuromuscular parameters nor result in greater central fatigue. Supraspinal fatigue develops and corticospinal excitability increases during endurance/ultra-endurance running and cycling, while the effects on inhibitory corticospinal mechanisms are equivocal and probably depend on exercise characteristics and TMS intensity
| Identifer | oai:union.ndltd.org:CCSD/oai:tel.archives-ouvertes.fr:tel-01057944 |
| Date | 28 October 2013 |
| Creators | Temesi, John |
| Publisher | Université Jean Monnet - Saint-Etienne |
| Source Sets | CCSD theses-EN-ligne, France |
| Language | English |
| Detected Language | English |
| Type | PhD thesis |
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