Mental fatigue impairs time trial performance in sub-elite under 23 cyclists

Adaptive cognitive tasks for mental fatigue: An innovative paradigm for cognitive loading in human performance

OBJECTIVES

Mental fatigue (MF) can impair cognitive and physical performance in sport. We tested the hypothesis that a shorter adaptive Time Load Dual Back (TLDB) task induces MF faster than a longer Stroop; and subsequently impairs cognitive and intermittent running performance.

DESIGN

This study employed a randomized within-participant design.

METHODS

25 trained individuals performed a Yo-Yo test after one of four experimental conditions (30-min Stroop, 20-min and 10-min TLDB tasks, and active control). Cognitive performance was assessed using the Psychomotor Vigilance Task (PVT) before and after the experimental conditions. Measures of mood, workload, MF, RPE, heart rate (HR), heart rate variability (HRV) and blood lactate were collected. ANOVAs determined the effect of the 4 conditions.

RESULTS

Stroop and 20-min TLDB conditions impaired running performance similarly (p = .015), while no differences are reported for 10-min TLDB and Control. No significant differences in physiological parameters were reported during the Yo-Yo test although RPE was significantly higher in the Stroop and 20-min TLDB conditions (p = .014). Stroop and both TLDBs conditions impaired PVT's cognitive performance (p = .029), MF (p = .012), mental demand (p < .001), HR (p = .021) and HRV (p = .033); with 20-min TLDB task having the higher significant impact. Mood alterations were similar between Stroop and TLDB conditions.

CONCLUSIONS

Intermittent running (Yo-Yo) and cognitive (PVT) performances, and subjective ratings were impaired by 30-min Stroop and 20-min TLDB tasks; while 10-min TLDB did not to impair performance. Shorter adaptive modes seem to be more effective in inducing MF and could have relevant clinical applications to assess conditions such as traumatic brain injury and concussion.

Comparing the cognitive performance of action video game players and age-matched controls following a cognitively fatiguing task: A stage 2 registered report

Recent work demonstrates that those who regularly play action video games (AVGs) consistently outperform non-gamer (NG) controls on tests of various cognitive abilities. AVGs place high demands on several cognitive functions and are often engaged with for long periods of time (e.g., over 2 h), predisposing players to experiencing cognitive fatigue. The detrimental effects of cognitive fatigue have been widely studied in various contexts where accurate performance is crucial, including aviation, military, and sport. Even though AVG players may be prone to experiencing cognitive fatigue, this topic has received little research attention to date. In this study, we compared the effect of a cognitively fatiguing task on the subsequent cognitive performance of action video game players and NG control participants. Our results indicated AVGs showed superior spatial working memory and complex attention abilities while showing no difference from NGs on simple attention performance. Additionally, we found that our cognitive fatigue and control interventions did not differentially affect the cognitive performance of AVGs and NGs in this study. This pre-registered study provides evidence that AVGs show superior cognitive abilities in comparison to a non-gaming population, but do not appear more resilient to cognitive fatigue.

Effect of mental fatigue on mean propulsive velocity, countermovement jump, and 100-m and 200-m dash performance in male college sprinters

The objective of this study was to analyze the effect of mental fatigue on mean propulsive velocity (MPV), countermovement jump (CMJ), 100, and 200-m dash performance in college sprinters. A total of 16 male athletes of sprint events (100 and 200-m dash) participated in this study. Each participant underwent two baseline visits and then running under the three experimental conditions. Assessments (MPV and CMJ) occurred both before and after either smartphone use (SMA) or Stroop task (ST), or watching a documentary TV show about the Olympic Games (CON). Then, the athletes ran the simulated race (i.e. the 100 and 200-m dash). There was no condition (p > 0.05) or time effect (p > 0.05) for MPV, CMJ, 100-m, or 200-m dash performance. In conclusion, the present study results revealed no mental fatigue effect induced by SMA or ST on neuromuscular, 100-m or 200-m dash performance in male college sprinters.

Mental Fatigue Impairs Second Serve Accuracy in Tennis Players

Purpose: The aim of this 2-week randomized, counterbalance and crossover study was to investigate the effect of acute mental fatigue (MF) on tennis serve performance and accuracy in tennis players. Methods: Ten male tennis players (18 ± 4 years, 1.80 ± 0.08 m; 71 ± 13 kg) were randomized to either the MF group (N = 5) that underwent an acute MF protocol or to a control (CON) group (N = 5). The MF condition consisted in a 30-min modified Stroop color word task performed before on-court serve speed test. A visual analogue scale (VAS) was used to assess the perceptions of MF and motivation toward the upcoming technical tests. Results: Reduction over baseline score of Stroop test was noted in accuracy (N < .001), but not in reaction time (N = .968) in the MF group. Increments in perceived workload were detected (N < .001) in MF group compared to CON. No differences for first and second serve speed from deuce and advantage side were observed. Increment of percentage of failed second serves from the deuce side (N = .043) in MF were detected. Conclusions: An acute MF protocol reduced tennis serve accuracy from deuce side in male tennis players. Players should avoid cognitive efforts before training sessions and matches to prevent negative effects of their technical performance.

The counteractive effects of interventions addressing mental fatigue on sport-specific performance among athletes: A systematic review with a meta-analysis

The deleterious consequences of mental fatigue (MF) on athletes in diverse sporting domains have been subject to extensive inquiry. However, the efficacy of interventions to counteract the effects of MF remains largely elusive. This review aims to evaluate the effects of counteractive interventions on the sport-specific performance of mentally fatigued athletes. Moreover, synthesizes the current evidence on which sports effectively counter the detrimental effects of MF with interventions, highlighting potential avenues for upcoming research. A systematic search was executed via Web of Science, Scopus, PubMed, and EBSCOhost, in addition to Google Scholar and references for grey literature. A meta-analysis was executed to compute effect sizes for different interventions with 13 qualified papers. Interventions include transcranial direct current stimulation, person-fit, mindfulness, glucose supplementation, caffeine mouth rinsing, and nature exposure showed potential to mitigate the detrimental effects on sport-specific performance, particularly in shooting accuracy (ES = 0.591; p = 0.001), decision-making accuracy (ES = 0.553; p = 0.006), and reaction time (ES = -0.871; p < 0.001), however, not in completion time (ES = -0.302; p = 0.182). This review underscores the unique roles of self-regulatory resources and directed attention. Nonetheless, a cautious interpretation of the findings is warranted given the paucity of investigations involving potential interventions in numerous other sports, such as volleyball, Australian football, cricket, and boxing.

Assessing the Evidential Value of Mental Fatigue and Exercise Research

It has often been reported that mental exertion, presumably leading to mental fatigue, can negatively affect exercise performance; however, recent findings have questioned the strength of the effect. To further complicate this issue, an overlooked problem might be the presence of publication bias in studies using underpowered designs, which is known to inflate false positive report probability and effect size estimates. Altogether, the presence of bias is likely to reduce the evidential value of the published literature on this topic, although it is unknown to what extent. The purpose of the current work was to assess the evidential value of studies published to date on the effect of mental exertion on exercise performance by assessing the presence of publication bias and the observed statistical power achieved by these studies. A traditional meta-analysis revealed a Cohen's dz effect size of - 0.54, 95% CI [- 0.68, - 0.40], p < .001. However, when we applied methods for estimating and correcting for publication bias (based on funnel plot asymmetry and observed p-values), we found that the bias-corrected effect size became negligible with most of publication-bias methods and decreased to - 0.36 in the more optimistic of all the scenarios. A robust Bayesian meta-analysis found strong evidence in favor of publication bias, BFpb > 1000, and inconclusive evidence in favor of the effect, adjusted dz = 0.01, 95% CrI [- 0.46, 0.37], BF10 = 0.90. Furthermore, the median observed statistical power assuming the unadjusted meta-analytic effect size (i.e., - 0.54) as the true effect size was 39% (min = 19%, max = 96%), indicating that, on average, these studies only had a 39% chance of observing a significant result if the true effect was Cohen's dz = - 0.54. If the more optimistic adjusted effect size (- 0.36) was assumed as the true effect, the median statistical power was just 20%. We conclude that the current literature is a useful case study for illustrating the dangers of conducting underpowered studies to detect the effect size of interest.

Effect of brain endurance training on maximal oxygen uptake, time-to-exhaustion, and inhibitory control in runners

We aimed to analyze the effect of brain endurance training on maximum oxygen consumption (VO2máx ), time-to-exhaustion, and inhibitory control in amateur trained runners. We employed a mixed experimental design, with the group as the between-participant factor and time as the within-participant factor. 45 participants attended 36 training sessions over 12 weeks. The cognitive training group (CT) performed the Stroop word-color task [trials of each type (congruent, incongruent, and neutral) were randomly presented during each training session], the endurance training group (ET) participated in a running training program (intensity was 60%Δ of maximal aerobic velocity and performed on a motor-driven treadmill), and the brain endurance training group (BET) make cognitive and endurance training simultaneously over 12 weeks. The total time of each session (i.e., 20-40 min) was identical in the experimental groups. VO2máx , time-to-exhaustion, and inhibitory control tests were measured before (baseline) and after (post-experiment) the 12-week intervention. A significant effect of interaction (group × time) for VO2máx (p < 0.05) was found. A post-hoc test showed an increase in VO2máx from baseline to post-experiment only for ET (Δ% = 2.98) and BET (Δ% = 3.78) groups (p < 0.05). Also, the analyses showed a significant interaction (group × time) for time-to-exhaustion (p < 0.05), and a post-hoc test revealed an improvement in time-to-exhaustion for ET (Δ% = 8.81) and BET (Δ% = 11.01) (p < 0.05). No group × time interaction was found for accuracy and response time in the inhibitory control task (p > 0.05). The results conclude that BET was not superior to ET for improving VO2máx and time-to-exhaustion. Also, the findings conclude that BET improved inhibitory control similar to CT.

Head-to-head opponent mitigates mental fatigue effects during a 20-km time trial in well-trained cyclists

We aimed to analyze the effect of a head-to-head virtual race on 20-km time trial performance in well-trained mentally fatigued cyclists. A total of 24 male professional cyclists participated in the present study, which was conducted in a within-factors design [four experimental conditions × four times (throughout 20-km time trial cycling)]. An avatar representing the participant on the racecourse was visible during the time trials. Then, a second virtual avatar representing the opponent was projected onto the screen in the mental fatigue head-to-head and control head-to-head experimental conditions. Measurements [rating of perceived exertion, heart rate, and eye-tracking measures (i.e., pupil diameter)] were performed every 5-km throughout the 20-km time trial. As a result, impaired total time, power output, and cadence throughout the 20-km cycling time trial were found for mental fatigue compared to mental fatigue head-to-head, control head-to-head, and control conditions (p < 0.05). Also, impaired 20-km time trial performance (total time, power output, and cadence) was found for mental fatigue head-to-head compared to control head-to-head (p < 0.05). Moreover, lower RPE was found for the control and control head-to-head conditions than mental fatigue head-to-head and mental fatigue experimental conditions (p < 0.05). Higher pupil diameter was also found for mental fatigue head-to-head, control head-to-head, and control than the mental fatigue experimental condition (p < 0.05). In summary, the overall performance throughout the 20-km cycling time trial was improved by the presence of a virtual opponent for the mentally fatigued cyclists.

Opposite effects of a time-trial and endurance cycling exercise on the neural efficiency of competitive cyclists

PURPOSE

Time-trial require cyclists to have an acute control on their sensory cues to regulate their pacing strategies. Pacing an effort accurately requires an individual to process sensory signals with efficacy, a factor that can be characterized by a high neural efficiency. This study aimed to investigate the effect of a cycling time-trial on neural efficiency in comparison to a low intensity endurance exercise, the latter supposedly not requiring high sensory control.

METHODS

On two separate days, 13 competitive cyclists performed a session comprising of two 10 min treadmill tests, performed at different intensity zones from 1 to 5 on the rating subjective exercise intensity scale. The tests were performed before and after both a time-trial and endurance cycling exercise. Electroencephalography activity was measured during each intensity zones of the treadmill exercises. Neural efficiency was then calculated for each intensity block using the α/β electroencephalography activity ratio.

RESULTS

The neural efficiency averaged on the 5 IZ decreased following the time-trial in the motor cortex (- 13 ± 8%) and prefrontal cortex (- 10 ± 12%), but not after the endurance exercise.

CONCLUSION

To conclude, the time-trial impaired the neural efficiency and increasing the RPE of the cyclists in the severe intensity zone.

Interindividual Variability in Mental Fatigue-Related Impairments in Endurance Performance: A Systematic Review and Multiple Meta-regression

BACKGROUND

The negative effect of mental fatigue (MF) on physical performance has recently been questioned. One reason behind this could lie in the interindividual differences in MF-susceptibility and the individual features influencing them. However, the range of individual differences in mental fatigue-susceptibility is not known, and there is no clear consensus on which individual features could be responsible for these differences.

OBJECTIVE

To give an overview of interindividual differences in the effects of MF on whole-body endurance performance, and individual features influencing this effect.

METHODS

The review was registered on the PROSPERO database (CRD42022293242). PubMed, Web of Science, SPORTDiscus and PsycINFO were searched until the 16th of June 2022 for studies detailing the effect of MF on dynamic maximal whole-body endurance performance. Studies needed to include healthy participants, describe at least one individual feature in participant characteristics, and apply at least one manipulation check. The Cochrane crossover risk of bias tool was used to assess risk of bias. The meta-analysis and regression were conducted in R.

RESULTS

Twenty-eight studies were included, with 23 added to the meta-analysis. Overall risk of bias of the included studies was high, with only three presenting an unclear or low rating. The meta-analysis shows the effect of MF on endurance performance was on average slightly negative (g = - 0.32, [95% CI - 0.46; - 0.18], p < 0.001). The multiple meta-regression showed no significant influences of the included features (i.e. age, sex, body mass index and physical fitness level) on MF-susceptibility.

CONCLUSIONS

The present review confirmed the negative impact of MF on endurance performance. However, no individual features influencing MF-susceptibility were identified. This can partially be explained by the multiple methodological limitations such as underreporting of participant characteristics, lack of standardization across studies, and the restricted inclusion of potentially relevant variables. Future research should include a rigorous description of multiple different individual features (e.g., performance level, diet, etc.) to further elucidate MF mechanisms.

Mental Fatigue: The Cost of Cognitive Loading on Weight Lifting, Resistance Training, and Cycling Performance

PURPOSE

Mental fatigue (MF) can impair physical performance in sport. We tested the hypothesis that cognitive load alone, and intermixed with standard resistance training, would induce MF, increase rating of perceived exertion (RPE), alter perception of weight lifting and training, and impair cycling time-trial performance.

METHODS

This 2-part study employed a within-participant design. In part 1, after establishing leg-extension 1-repetition maximum (1RM), 16 participants lifted and briefly held weights at 20%, 40%, 60%, and 80% of 1RM. RPE and electromyography (EMG) were measured for each lift. During the testing sessions, participants completed cognitive tasks (MF condition) or watched neutral videos (control condition) for 90 minutes before lifting the weights. In part 2, they completed submaximal resistance training comprising 6 weight training exercises followed by a 20-minute cycling time trial. In the MF condition, they completed cognitive tasks before and between weight training exercises. In the control condition, they watched neutral videos. Mood (Brunel Mood Scale), workload (National Aeronautics and Space Administration Task Load Index), MF-visual analogue scale (MF-VAS), RPE, psychomotor vigilance, distance cycled, power output, heart rate, and blood lactate were measured.

RESULTS

In part 1, the cognitive task increased lift-induced RPE (P = .011), increased MF-VAS (P = .002), and altered mood (P < .001) compared with control. EMG did not differ between conditions. In part 2, the cognitive tasks increased RPE (P < .001), MF-VAS (P < .001), and mental workload (P < .001), but reduced cycling time-trial power (P = .032) and distance (P = .023) compared with control. Heart rate and blood lactate did not differ between conditions.

CONCLUSION

A state of MF induced by cognitive load, alone or intermixed with physical load, increased RPE during weight lifting and training and impaired subsequent cycling performance.

A plausible link between the time-on-task effect and the sequential task effect

Mental fatigue can be studied by using either the time-on-task protocol or the sequential task protocol. In the time-on-task protocol, participants perform a long and effortful task and a decrease in performance in this task is generally observed over time. In the sequential task protocol, a first effortful or control task is followed by a second effortful task. The performance in the second task is generally worse after the effortful task than after the control task. The principal aim of the present experiment is to examine the relationship between these two decrements in performance while concomitantly using a sequential task protocol and assessing the performance of the first effortful task as a function of time-on-task. We expect a positive correlation between these two decrements in performance. A total of 83 participants performed a 30-min fatiguing mental task (i.e., a modified Stroop task) or a control task followed by a time-to-exhaustion handgrip task. As expected, this protocol combining the time-on-task and sequential task protocols allowed us to observe (1) a decrease in performance over time during the Stroop task, (2) a worst performance in the handgrip task after the Stroop task by comparison to the control task, (3) a positive correlation between these two effects. The decrease in performance during the Stroop task also correlated with the subjective measures of boredom and fatigue, whereas the detrimental effect observed in the handgrip task did not. Our findings suggest that the two fatigue-related phenomena share a common mechanism but are not completely equivalent.

Non-invasive brain stimulation over the orbital prefrontal cortex maintains endurance performance in mentally fatigued swimmers

BACKGROUND

Using anodal transcranial direct current stimulation (a-tDCS) on frontal brain areas might be a promising strategy to mitigates mental fatigue and maintain endurance performance swimmers.

OBJECTIVE

The objective was to analyze the effect of a-tDCS over the orbital prefrontal cortex (oPFC) on endurance performance of mentally fatigued female amateur swimmer.

METHODS

Nineteen female amateur swimmers participated in this study. In two experimental visits, the swimmers completed the 3-min all-out tethered swimming after performing a 30-min Stroop test with a-tDCS or placebo (Sham) stimulation over the left-oPFC. The brain stimulation conditions (i.e., a-tDCS and Sham) were performed in a double-blinded and counterbalanced order.

RESULTS

It was found lower critical force, mean force, force minimum, fatigue index, and aerobic impulse for Sham than a-tDCS (p < 0.05). There was no main effect of condition for peak force (p >  0.05).

CONCLUSION

We concluded that a-tDCS applied over the left-oPFC in female amateur swimmers mentally fatigued maintained endurance performance. From a practical point of view, the use of a-tDCS should be considered to counteract harmful cognitive effects and maintain endurance performance during competitive race events.

Power Road-Derived Physical Performance Parameters in Junior, Under-23, and Professional Road Cycling Climbers

PURPOSE

To investigate the relationship of field-derived power and physical performance parameters with competition success in road cycling climbing specialists of age-related categories and to explore cross-sectional differences between high-ranked (HIGHR) climbing specialists of each category.

METHODS

Fifty-three male climbers participated in this study (junior [JUN], n = 15; under 23 [U23], n = 21; professional [PRO], n = 17). Training and racing data collected during the 2016-19 competitive seasons were retrospectively analyzed for record power outputs (RPOs) and RPOs after prior accumulated work.

RESULTS

In JUN, body mass, absolute RPOs, and relative RPOs were higher in HIGHR compared with low ranked (d = 0.97-2.20, large; P = .097-.001); in U23 and PRO, the percentage decrease in RPOs after 20, 30, 40, and 50 kJ·kg-1 was less in HIGHR compared with low ranked (d = 0.77-1.74, moderate-large; P = .096-.004). JUN HIGHR presented lower absolute and relative RPO-20 min (ηp2=.34-.38, large; P = .099-.001) and higher percentage decrease in RPOs after prior accumulated work compared with U23 and PRO HIGHR (ηp2=.28-.68, large; P = .060-.001); percentage decrease in RPOs after prior accumulated work was the only parameter differentiating U23 and PRO HIGHR, with PRO declining less in relative RPO-1 min, RPO-5 min, and RPO-20 min after 20 to 50 kJ·kg-1 (ηp2=.28-.68, large; P = .090-.001).

CONCLUSIONS

Superior absolute and relative RPOs characterize HIGHR JUN climbing specialists. Superior fatigue resistance differentiates HIGHR U23 and PRO climbers compared with low ranked, as well as PRO versus U23 climbers.

Mental Fatigue and Basketball Performance: A Systematic Review

Mental fatigue (MF) is a psycho-biological state that impairs sports-related performances. Recently, it has been proved that MF can affect basketball performance. However, a systematic overview detailing the influences of MF on basketball performance is still lacking. This study aims to investigate the effects of MF on the physical, technical, tactical, and cognitive performance of basketball. We used the databases of PubMed, Web of Science, SPORTDiscus, Scopes, and CKNI for articles published up to 31 May 2021. The articles included in this study were projected to test whether MF influences basketball athlete performance. Only experimental design studies were selected, and the control condition was without MF. Finally, seven articles fit the inclusion criteria. The results imply that MF impairs the technical aspects of basketball (free throws, three-point shots, and total turnover) and the players' cognitive [take-the-first (TTF) heuristics and decision-making] performance, which results in athletes not using their techniques skillfully and being unable to make practical decisions during critical points in the game. In addition to that, the influences of MF on physical and tactical performance have not been studied. Further studies should look into comprehensive research on the influences of MF on basketball performance, especially on a player's physical and tactical performance.

Systematic Review Registration: [https://inplasy.com/] [INPLASY2021100017].

Effects of Nutritional Interventions on Accuracy and Reaction Time with Relevance to Mental Fatigue in Sporting, Military, and Aerospace Populations: A Systematic Review and Meta-Analysis

Background: Research in sport, military, and aerospace populations has shown that mental fatigue may impair cognitive performance. The effect of nutritional interventions that may mitigate such negative effects has been investigated. This systematic review and meta-analysis aimed to quantify the effects of nutritional interventions on cognitive domains often measured in mental fatigue research. Methods: A systematic search for articles was conducted using key terms relevant to mental fatigue in sport, military, and aerospace populations. Two reviewers screened 11,495 abstracts and 125 full texts. A meta-analysis was conducted whereby effect sizes were calculated using subgroups for nutritional intervention and cognitive domains. Results: Fourteen studies were included in the meta-analysis. The consumption of energy drinks was found to have a small positive effect on reaction time, whilst the use of beta-alanine, carbohydrate, and caffeine had no effect. Carbohydrate and caffeine use had no effect on accuracy. Conclusions: The results of this meta-analysis suggest that consuming energy drinks may improve reaction time. The lack of effect observed for other nutritional interventions is likely due to differences in the type, timing, dosage, and form of administration. More rigorous randomized controlled trials related to the effect of nutrition interventions before, during, and after induced mental fatigue are required.

Effects of Mental Fatigue Induced by Social Media Use on Volleyball Decision-Making, Endurance, and Countermovement Jump Performance

We studied the effects of repeated inducements of mental fatigue (MF) from using social media on smartphones immediately before training sessions by young male volleyball athletes, focusing specifically on their decision-making, endurance, and countermovement jump performance (CMJ). We pair-matched 24 participants according to their decision-making abilities and then, randomly assigned them to one of two 4-week block training groups: control (CON) and smartphone use (SMA). For a 30-minute period before each training session, the CON group watched TV and the SMA group used social media apps on smartphones. We found a significant group x time interaction effect for decision making (attack, p = 0.03; passing, p = 0.02) during training blocks. More specifically, only the CON group improved their decision making (attack, p = 0.03; passing, p = 0.02). Both groups significantly improved their CMJ performance (p = .01), with no significant group x time interaction effect for CMJ (p = 0.91). Neither group significantly improved their endurance (p = 0.56). We concluded that 30-minutes of repetitive social media app use on a smartphone immediately before 4-weeks of volleyball training sessions negatively affected decision-making in young male volleyball athletes.

Impact of a Carbohydrate Mouth Rinse on Corticomotor Excitability after Mental Fatigue in Healthy College-Aged Subjects

Mental Fatigue (MF) has been associated with reduced physical performance but the mechanisms underlying this result are unclear. A reduction in excitability of the corticomotor system is a way mental fatigue could negatively impact physical performance. Carbohydrate (CHO) mouth rinse (MR) has been shown to increase corticomotor excitability. PURPOSE: The purpose of this study was to determine if CHO MR impacts corticomotor excitability after MF. METHODS: Fifteen subjects (nine females, six males; age = 23 ± 1 years; height = 171 ± 2 cm; body mass = 69 ± 3 kg; BMI = 23.8 ± 0.7) completed two sessions under different MR conditions (Placebo (PLAC), 6.4% glucose (CHO)) separated by at least 48 h and applied in a double-blinded randomized fashion. Motor-evoked potential (MEP) of the left first dorsal interosseous (FDI) was determined by transcranial magnetic stimulation (TMS) before and after MF. Perceived MF was recorded before and after the MF task using a 100 mm visual analog scale (VAS). RESULTS: MF was greater following PLAC (+30.4 ± 4.0 mm) than CHO (+19.4 ± 3.9 mm) (p = 0.005). MEP was reduced more following PLAC (−16.6 ± 4.4%) than CHO (−3.7 ± 4.7%) (p < 0.001). CONCLUSIONS: CHO MR was successful at attenuating the reduction in corticomotor excitability after MF. Carbohydrate mouth rinse may be a valuable tool at combating the negative consequences of mental fatigue.

How do elite female team sport athletes experience mental fatigue? Comparison between international competition, training and preparation camps

Mental fatigue has been shown to negatively influence physical, technical and tactical aspects of sporting performance. However, mental fatigue is not routinely monitored or managed in elite sport and it is not clear whether mental fatigue occurs and/or changes across the varied contextual demands experienced by elite athletes in training, preparation and competition. This study explored self-report measures of mental fatigue across eight training camps and six competition periods (two benchmark tournaments and four international test series) with international netballers (n = 22, 25.9 ± 2.7 years) during the 2018-2019 representative period. Mental fatigue was higher during training camps (p < 0.001; 3.20 [3.12, 3.27]) and preparation camps (p < 0.05; 3.27 [3.19, 3.34]) compared to the competition periods (3.49 [3.44, 3.55]). Significant within-group differences were also identified between individual preparation camps and competition subsets. Higher mental fatigue was reported during the preparation camp for international test series 2 comparative to the preparation camp for benchmark tournament 1 (p = 0.047). For individual competitions; greater mental fatigue was found during the international test series 3 competition in comparison to both the benchmark tournament 1 (p <0.001) and international test series 1 (p = 0.020) competition periods. International representative netballers experience differing levels of mental fatigue across training and preparation camps and competition periods. Practitioners should be aware that athletes report instances of elevated mental fatigue across camps, and competition. Mental fatigue is not limited to competition and thus is recommended to be monitored during periods of training and preparation for competition. HighlightsInternational representative netballers experience differing levels of mental fatigue across camp and competition environments.Mental fatigue was higher during training camps and preparation camps compared to the competition periods.Mental fatigue is not limited to competition so is recommended to be monitored during periods of training and preparation for competition.

The Impact of Fluid Loss and Carbohydrate Consumption during Exercise, on Young Cyclists' Fatigue Perception in Relation to Training Load Level

High-level young athletes need to face a wide spectrum of stressors on their journey to élite categories. The aims of the present study are (i) to evaluate session rate of perceived exertion (sRPE) at different training impulse (TRIMP) categories and the correlations between these two variables and, (ii) evaluate the correlations between sRPE, fluid loss, and carbohydrate consumption during exercise. Data on Edward’s TRIMP, sRPE, body mass loss pre- and post- exercise (∆), and carbohydrate consumption (CHO/h) during exercise have been acquired from eight male junior cyclists during a competitive season. One-way ANOVA and correlation analysis with linear regression have been performed on acquired data. sRPE resulted in a significant difference in the three TRIMP categories (p < 0.001). sRPE resulted in being very largely positively associated with TRIMP values (p < 0.001; R = 0.71). ∆ as well as CHO/h was largely negatively related with sRPE in all TRIMP categories (p < 0.001). The results confirmed the role of fluid balance and carbohydrate consumption on the perception of fatigue and fatigue accumulation dynamics independently from the training load. Young athletes’ training load monitoring and nutritional-hydration support represent important aspects in athlete’s exercise-induced fatigue management.

Mental Fatigue Reduces Training Volume in Resistance Exercise: A Cross-Over and Randomized Study

The present study aimed to determine the effect of mental fatigue (MF) on total training volume (TTV; number of repetitions x number of sets x load) and on ratings of perceived exertion (RPE; Borg, 1982) in the half-back squat exercise (HBSE). Nine male subjects (M age = 22.6 years, SD =  2.3; M height = 172.3 cm, SD =  6.8; M weight = 76.2 kg, SD =  9.8; M years of resistance training experience = 4.1, SD = 2.3 years) recruited from a university population were study participants in this participant-blind cross-over and randomized study. Participants underwent either the Stroop task - a highly demanding cognitive task (CT) - or a control condition (CON) in which they viewed a documentary exhibition for 30 minutes. Perception of MF and motivation were assessed after treatments using a visual analog scale of 100 mm. Participants then engaged in a countermovement jump (CMJ) test and three sets of HBSE until they reached momentary concentric failure, reporting RPE at the end of each exercise set. Following the CT, participants showed a significantly increased self-perception of MF in relation to the CON condition (p = 0.01; d = 1.2), but this did not affect their motivation to engage in subsequent tests (p = 0.99; d = 0.006). Neither the CMJ performances nor the RPE were statistically different between CT and CON conditions (p = 0.33; d = 0.09 and p = 0.20; η² = 0.20, respectively). TTV was significantly lower in the CT relative to the CON experimental condition (Δ = -15.8%; p = 0.04; η² = 0.48). Prolonged involvement in a CT was associated with reduced volume on a resistance exercise, though this effect was not associated with changes in CMJ performance or motivation to exercise.

Dissociable Effects of Executive Load on Perceived Exertion and Emotional Valence during Submaximal Cycling

Endurance physical exercise is accompanied by subjective perceptions of exertion (reported perceived exertion, RPE), emotional valence, and arousal. These constructs have been hypothesized to serve as the basis for the exerciser to make decisions regarding when to stop, how to regulate pace, and whether or not to exercise again. In dual physical-cognitive tasks, the mental (executive) workload generated by the cognitive task has been shown to influence these perceptions, in ways that could also influence exercise-related decisions. In the present work, we intend to replicate and extend previous findings that manipulating the amount of executive load imposed by a mental task, performed concomitantly with a submaximal cycling session, influenced emotional states but not perceived exertion. Participants (experienced triathletes) were asked to perform a submaximal cycling task in two conditions with different executive demands (a two-back version of the n-back task vs. oddball) but equated in external physical load. Results showed that the higher executive load condition elicited more arousal and less positive valence than the lower load condition. However, both conditions did not differ in RPE. This experimental dissociation suggests that perceived exertion and its emotional correlates are not interchangeable, which opens the possibility that they could play different roles in exercise-related decision-making.