Effects of Mental Fatigue on Physical Endurance Performance and Muscle Activation Are Attenuated by Monetary Incentives

2017 ◽  
Vol 39 (6) ◽  
pp. 385-396 ◽  
Author(s):  
Denver M.Y. Brown ◽  
Steven R. Bray
2019 ◽  
Author(s):  
Louis-Solal Giboin ◽  
Wanja Wolff

Two independent lines of research propose that exertion of mental effort can impair subsequent performance due to ego depletion or mental fatigue. In this meta-analysis, we unite these research fields to facilitate a greater exchange between the two, to summarize the extant literature and to highlight open questions. We performed a meta-analysis to quantify the effect of ego-depletion and mental fatigue on subsequent physical endurance performance (42 independent effect sizes). We found that ego-depletion or mental fatigue leads to a reduction in subsequent physical endurance performance (ES = -0.506 [95% CI: -0.649, -0.369]) and that the duration of prior mental effort exertion did not predict the magnitude of subsequent performance impairment (r = -0.043). Further, analyses revealed that effects of prior mental exertion are more pronounced in subsequent tasks that use isolation tasks (e.g., handgrip; ES = -0.719 [-0.946, -0.493]) compared to whole-body endurance tasks (e.g. cycling; coefficient = 0.338 [0.057, 0.621]) and that the observed reduction in performance is higher when the person-situation fit is low (ES for high person-situation fit = -0.355 [-0.529, -0.181], coefficient for low person-situation fit = -0.336 [-0.599, -0.073]). Taken together, the aggregate of the published literature on ego depletion or mental fatigue indicates that prior mental exertion is detrimental to subsequent physical endurance performance. However, this analysis also highlights several open questions regarding the effects’ mechanisms and moderators. Particularly, the surprising finding that the duration of prior mental exertion seems to be unrelated to subsequent performance impairment needs to be addressed systematically.


2019 ◽  
Vol 41 (5) ◽  
pp. 289-297
Author(s):  
Kristy Martin ◽  
Kevin G. Thompson ◽  
Richard Keegan ◽  
Ben Rattray

The aim of this study was to investigate whether individuals who engage in more frequent self-regulation are less susceptible to mental fatigue. Occupational cognitive demand and participation in sports or exercise were quantified as activities requiring self-regulation. Cardiorespiratory fitness was also assessed. On separate occasions, participants either completed 90 min of an incongruent Stroop task (mental exertion condition) or watched a 90-min documentary (control condition). Participants then completed a cycling time-to-exhaustion (physical endurance) test. There was no difference in the mean time to exhaustion between conditions, although individual responses varied. Occupational cognitive demand, participation in sports or exercise, and cardiorespiratory fitness predicted the change in endurance performance (p = .026, adjusted R2 = .279). Only cognitive demand added significantly to the prediction (p = .024). Participants who reported higher levels of occupational cognitive demand better maintained endurance performance following mental exertion.


Author(s):  
Fabio Giuseppe Laginestra ◽  
Markus Amann ◽  
Emine Kirmizi ◽  
Gaia Giuriato ◽  
Chiara Barbi ◽  
...  

Muscle fatigue induced by voluntary exercise, which requires central motor drive, causes central fatigue that impairs endurance performance of a different, non-fatigued muscle. This study investigated the impact of quadriceps fatigue induced by electrically-induced (no central motor drive) contractions on single-leg knee-extension (KE) performance of the subsequently exercising ipsilateral quadriceps. On two separate occasions, eight males completed constant-load (85% of maximal power-output) KE exercise to exhaustion. In a counterbalanced manner, subjects performed the KE exercise with no pre-existing quadriceps fatigue in the contralateral leg on one day (No-PreF), while on the other day, the same KE exercise was repeated following electrically-induced quadriceps fatigue in the contralateral leg (PreF). Quadriceps fatigue was assessed by evaluating pre- to post-exercise changes in potentiated twitch force (ΔQtw,pot; peripheral-fatigue), and voluntary muscle activation (ΔVA; central-fatigue). As reflected by the 57±11% reduction in electrically-evoked pulse force, the electrically-induced fatigue protocol caused significant knee-extensors fatigue. KE endurance time to exhaustion was shorter during PreF compared to No-PreF (4.6±1.2 vs 7.7±2.4 min; p<0.01). While ΔQtw,pot was significantly larger in No-PreF compared to PreF (-60% vs -52%, p<0.05), ΔVA was greater in PreF (-14% vs -10%, p<0.05). Taken together, electrically-induced quadriceps fatigue in the contralateral leg limits KE endurance performance and the development of peripheral fatigue in the ipsilateral leg. These findings support the hypothesis that the crossover-effect of central fatigue is mainly mediated by group III/IV muscle afferent feedback and suggest that impairments associated with central motor drive may only play a minor role in this phenomenon.


1995 ◽  
Vol 73 (12) ◽  
pp. 1765-1773 ◽  
Author(s):  
E. Cafarelli ◽  
F. Liebesman ◽  
J. Kroon

One of the consequences of endurance training is a reduction in force sensation in trained muscles at any exercise intensity. To study the central and peripheral contributions to this adaptation, we trained six male subjects with single-leg cycling at 60% [Formula: see text] peak (30 min/day × 3 days/week × 8 weeks); six others were matched controls. Measurements were made during separate 20-min, single-leg rides at 70% pre-training [Formula: see text] peak, with trained (TR), untrained (UT), and control (CT) legs, before and after training. No pre–post differences were observed in the control group. [Formula: see text] peak increased 18% (p < 0.05) in the TR leg and 6% (p < 0.05) in the UT leg of the trained subjects. Force sensation was significantly less in both the TR (70%; p < 0.05) and UT (50%; p < 0.05) legs during 20 min of single-leg cycling after training. Vastus lateralis EMG, plasma lactate, and heart rate were all significantly (p < 0.05) lower when cycling with either the TR or UT leg, which were both lower than when cycling with the CT leg, at the end of each 20-min ride. These data reflect an intramuscular environment that is better adapted to endurance performance by virtue of both central and peripheral mechanisms. Thus, there is less need to recruit additional motor units to maintain the same power output, and this reduced motor outflow leads to a decline in force sensation.Key words: kinesthesia, proprioception, electromyography, single-leg training, endurance training.


2018 ◽  
Vol 9 ◽  
Author(s):  
Lieke Schiphof-Godart ◽  
Bart Roelands ◽  
Florentina J. Hettinga

2019 ◽  
Vol 9 (1) ◽  
pp. 114 ◽  
Author(s):  
Joris C Verster ◽  
Aikaterini Anogeianaki ◽  
Darren Kruisselbrink ◽  
Chris Alford ◽  
Ann-Kathrin Stock

Alcohol hangover is a potentially debilitating state. Several studies have demonstrated that it does not seem to impair strength or short-term endurance, but its effects on continuous exercise performance/long-term endurance have never been investigated. Therefore, the aim of the current study was to assess hiking performance of participants who walked the 15.8 km Samaria Gorge in Crete, Greece. Participants completed a survey in the morning before walking the Gorge, and in the afternoon after completion of the walk. Demographics, data on previous evening alcohol consumption, sleep, hangover symptoms, and walking performance were assessed. Data from N = 299 participants with a mean (SD) age of 38.9 (11.0) years were analyzed. N = 223 participants (74.6%) consumed alcohol the evening before walking the Samaria Gorge, and N = 176 (78.9%) of those reported a hangover. They consumed a mean (SD) of 3.0 (1.8) alcoholic drinks (10 g alcohol each) with a corresponding next-morning hangover severity of 4.6 (2.4) on a 0–10 scale. Participants with a hangover reported feeling significantly more exhausted after the walk compared to participants with no hangover. The groups did not significantly differ in duration of the walk, and the number and duration of breaks. Overall hangover severity, assessed either before, during, or after walking the Samaria Gorge was not significantly correlated with any walking outcome. In conclusion, hungover participants experienced significantly more exhaustion when performing physical activity at the same level as non-hungover participants.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 1076-1076
Author(s):  
Halle C. F. Moore ◽  
Michael W. Parsons ◽  
Guang H. Yue ◽  
Lisa A. Rybicki ◽  
Vlodek Siemionow

1076 Background: Cognitive impairment is a poorly understood and worrisome potential complication of adjuvant chemotherapy (CT). We sought to evaluate electroencephalography (EEG) as a means to measure neurophysiologic function in women receiving CT for early breast cancer. Methods: Women planning to undergo CT for operable breast cancer and age-similar controls were evaluated at baseline, during CT and at 1 year with neurophysiologic assessments. Testing included a brief fatigue inventory (BFI), brief mental fatigue assessment (BMF), Processing Speed Index (PSI) derived from Digit Symbol Coding and Symbol Search subtests of the Wechsler Adult Intelligence Scale, and a sustained elbow flexion physical task (PT). EEG recordings were obtained at rest and after the cognitive and physical tasks. Data were analyzed using repeated measures of analysis of variance. Results: Eight patient/control pairs completed baseline and on-treatment evaluations; 7 pairs also completed the 1 year assessment (1 pair withdrawn due to a second malignancy). Subjective mental fatigue measured by BMF is similar for patients and controls at baseline but BMF scores increase significantly during CT for patients relative to controls (p=0.033), recovering to no difference at one year. Differences in PSI are not observed between patients and controls or at the different time points. BFI scores are greater in patients at all 3 time points but endurance on the PT is no different from controls. During chemotherapy EEG total spectrum amplitudes in patients are greater than in controls at rest (p=0.05) and following both the cognitive (p<0.001) and physical (p<0.001) tasks. EEG activity prior to chemotherapy and at one year is not different between patients and controls. For patients but not controls EEG readings after the cognitive task demonstrate greater amplitude than pre-task readings during the time of CT treatment only (p=0.012) with a similar trend seen for the physical task (p=0.06). Conclusions: Patient-perceived mental and physical fatigue during chemotherapy correspond to significant changes in EEG brain activity patterns but not to cognitive testing or physical endurance testing. EEG may offer a sensitive means to measure alterations in brain function associated with CT.


2016 ◽  
Vol 41 (8) ◽  
pp. 825-831 ◽  
Author(s):  
Rogério Santos de Oliveira Cruz ◽  
Rafael Alves de Aguiar ◽  
Tiago Turnes ◽  
Amadeo Félix Salvador ◽  
Fabrizio Caputo

It has been demonstrated that ischemic preconditioning (IPC) improves endurance performance. However, the potential benefits during anaerobic events and the mechanism(s) underlying these benefits remain unclear. Fifteen recreational cyclists were assessed to evaluate the effects of IPC of the upper thighs on anaerobic performance, skeletal muscle activation, and metabolic responses during a 60-s sprint performance. After an incremental test and a familiarization visit, subjects were randomly submitted in visits 3 and 4 to a performance protocol preceded by intermittent bilateral cuff inflation (4 × (5 min of blood flow restriction + 5 min reperfusion)) at either 220 mm Hg (IPC) or 20 mm Hg (control). To increase data reliability, each intervention was replicated, which was also in a random manner. In addition to the mean power output, the pulmonary oxygen uptake, blood lactate kinetics, and quadriceps electromyograms (EMGs) were analyzed during performance and throughout 45 min of passive recovery. After IPC, performance was improved by 2.1% compared with control (95% confidence intervals of 0.8% to 3.3%, P = 0.001), followed by increases in (i) the accumulated oxygen deficit, (ii) the amplitude of blood lactate kinetics, (iii) the total amount of oxygen consumed during recovery, and (iv) the overall EMG amplitude (P < 0.05). In addition, the ratio between EMG and power output was higher during the final third of performance after IPC (P < 0.05). These results suggest an increased skeletal muscle activation and a higher anaerobic contribution as the ultimate responses of IPC on short-term exercise performance.


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