8.2 - Integration: CC, EPR and RPE Flashcards
What did Noakes (1996) propose??
The central governor model.
This is where fatigue results from a failure to maintain homeostasis either in active muscles or in the CNS.
Continuous feedback from various systems is integrated to regulate exercise by continuously modifying the number of MU recruited in the exercising limbs
Marcora (2008) proposed the psychobiological model, what did this involve???
Motivational intensity theory, when reward>cost = persistence
The perception of effort is centrally generated (efferencekopie)
Fatigue is voluntary due to response to a high perception of effort.
Any intervention to change performance without changing the RPE or motivation would disprove the model
Partially agreed with Noakes, but believed endurance exercise was regulated by perception of effort. Generated either centrally (CC) or peripherally (afferent feedback)
Discuss Hureau et al (2018), looking at sensory tolerance limit??
Traditionally just a) muscle afferent feedback
Proposed b) corollary discharges and the sum of all muscle afferent feedback .
Extends the critical threshold of peripheral fatigue (i.e. CGM)
Afferent feedback and efferent signals are processed within the CNS and regulate the intensity of exercise to ensure that voluntary activity remains tolerable
Discuss the serotonin hypothesis (Meeusen et al, 2006)???
Increase in brain serotonergic activity during prolonged activity augments lethargy and a loss of drive.
Reduced MU recruitment
This is however a lack of evidence for this (only SSRI studies and BCAA interventions).
Brain dopamine and NA - enhance ex performance in the heat
Discuss is fatigue all neurochemistry (Meeusen + Roelands, 2018)
⬆️dopamine caused improved performance in heat (normal temp - inconclusive)
⬆️NA caused decreased performance
⬇️Serotonin when fed BCAA was inconclusive, ⬆️performance when fed CHO
⬆️serotonin from reputable inhibitor and tryptophan was inconclusive.
Discuss the strength control model Baumeister et al (2007)??
Self control is described to a muscle - the more self control that is exerted, the more fatigued it becomes, which impacts on subsequent events which also require self-control resources
Initially applied to things like binge eating, now applied to control of effect during exercise.
Discuss the implications involved with complex regulation of human exercise (Noakes, 2011)??
Music, placebos, self-belief, psychological skills training all ⬇️RPE therefore ⬆️performance.
Mental fatigue, sleep deprivation both ⬆️RPE therefore ⬇️performance.
Discuss Marcora et al (2009) - mental fatigue impairs endurance performance??
Compared a mental fatigue conditions vs a control condition on AX continuous performance test looking at working memory, response inhibition and error monitoring.
The results showed a 15% reduction in fixed workload cycle task for mental fatigue.
Both groups quit at same RPE level.
Briefly discuss Van cutsem et al (2017)??
Mental fatigue is well established to impair sub maximal performance
Discuss briefly Martin et al (2015)??
Mental fatigue does not impair maximal anaerobic exercise performance
Discuss the mental fatigue work in elite athletes?? (Martin et al, 2016)
Looked at pro cyclists and recreational cyclists.
Pros had superior cognitive performance suggesting a higher inhibitory control. 30 mins of cognitive task did not impair elite groups performance. Pros also have a greater resistance to mental fatigue.
These characteristics could be either genetic or developed.
Discuss the rational of brain endurance training proposed by Marcora??
The repetition of mentally fatiguing tasks will :- increase training load on the brain , induces adaptation in the ACC or other relevant cortical areas, reduces perception of effort and ⬆️endurance performance.
Discuss the methods of the key BET study from HMSO (2013)???
40 active males were assigned to either BET or control. Both groups trained on a cycle ergometer for 60 minutes @ 65% VO2 max, 3X a week for 12 weeks. During the cycling the BET group performed a mentally fatiguing task (60 min of the ax -CPT task).
Discuss the results of the key BET study (HMSO, 2013)??
Results showed HR same. During training - mental demand, temporal demand, performance and effort were all significantly higher for the brain training group compared to normal.
Relative VO2 max was significantly higher pre-post for both groups.
BET task took significantly longer to exhaustion and produced significantly more work (kj)
Discuss Marcora et al (2015) regarding cognitive training?
Engaging in cognitive tasks during exercise (i.e. BET) can develop a resilience to mental fatigue and ⬆️physical performance compared to physical training alone.
