Search

Purpose This study aimed at comparing the predictive accuracy of the power law (PL), 2-parameter hyperbolic (HYP) and linear (LIN) models on elite 1-h track running performance, and evaluating pacing profile and running pattern of the men’s best two 1-h track running performances of all times. Methods The individual running speed–distance profile was obtained for nine male elite runners using the three models. Different combinations of personal bests times (3000 m-marathon) were used to predict performance. The level of absolute agreement between predicted and actual performance was evaluated using intraclass correlation coefficient (ICC), paired t test and Bland–Altman analysis. A video analysis was performed to assess pacing profile and running pattern. Results Regardless of the predictors used, no significant differences (p > 0.05) between predicted and actual performances were observed for the PL model. A good agreement was found for the HYP and LIN models only when the half-marathon was the longest event predictor used (ICC = 0.718–0.737, p CS, PLV20 (i.e., the running speed corresponding to a 20-min performance estimated using the PL model) was associated with 1-h track running performances (r = 0.722–0.807, p Conclusions The PL model may offer the more realistic 1-h track running performance prediction among the models investigated. An even pacing might be the best strategy for succeeding in such running events.

Purpose: Sleep deprivation (SD) is very common during ultraendurance competitions. At present, stimulants such as caffeine and naps are the main strategies used to reduce the negative effects of SD on ultraendurance performance. In this case study, the authors describe the application of a novel strategy consisting of the intermittent repetition of SD (SD training [SDT]) during the weeks preceding an ultraendurance competition. Methods: A male ultraendurance runner underwent a 6-week SDT program (consisting of 1 night SD every Sunday) in addition to his regular physical training program before taking part in a 6-day race. Before and after SDT, the participant performed 5 consecutive days of daily 2-hour constant-pace running with SD on the first and third night. Psychological and physiological responses were measured during this multiday test. Results: SDT was well tolerated by the athlete. A visual analysis of the data suggests that including SDT in the weeks preceding an ultraendurance competition may have beneficial effects on sleepiness and perceived mental effort in the context of 5 consecutive days of prolonged running and 2 nights of SD. This multiday test seems a feasible way for assessing ultraendurance athletes in the laboratory. Conclusions: The results provided some encouraging initial information about SDT that needs to be confirmed in a randomized controlled trial in a group of ultraendurance athletes. If confirmed to be effective and well tolerated, SDT might be used in the future to help ultraendurance athletes and other populations that have to perform in conditions of SD.

There is potential in delivering brief, educational interventions online, particularly for recreational athletes. This initial investigation examined how two online interventions were perceived by endurance participants and how they affected outcomes of interest. After measuring self-efficacy, 142 people were randomized to one of three groups (self-talk, implementation intentions, and control) before an endurance event. Ninety-four completed postevent measures, which were self-efficacy, goal attainment, performance satisfaction, coping, stress appraisals, and social validity. The interventions involved approximately 10 min of initial engagement with online material. Perceptions of stress controllability were significantly higher in the implementation intention group compared with the control. There were no other statistically significant effects. Nevertheless, both intervention groups were satisfied with their interventions, found them useful, and were planning to continue using them. The findings demonstrate the feasibility and value of using brief, online psychological interventions, which may be timely in our changing profession, as COVID-19 has moved many interventions online.

A conceptual framework has a central role in the scientific process. Its purpose is to synthesize evidence, assist in understanding phenomena, inform future research and act as a reference operational guide in practical settings. We propose an updated conceptual framework intended to facilitate the validation and interpretation of physical training measures. This revised conceptual framework was constructed through a process of qualitative analysis involving a synthesis of the literature, analysis and integration with existing frameworks (Banister and PerPot models). We identified, expanded, and integrated four constructs that are important in the conceptualization of the process and outcomes of physical training. These are: (1) formal introduction of a new measurable component ‘training effects’, a higher-order construct resulting from the combined effect of four possible responses (acute and chronic, positive and negative); (2) explanation, clarification and examples of training effect measures such as performance, physiological, subjective and other measures (cognitive, biomechanical, etc.); (3) integration of the sport performance outcome continuum (from performance improvements to overtraining); (4) extension and definition of the network of linkages (uni and bidirectional) between individual and contextual factors and other constructs. Additionally, we provided constitutive and operational definitions, and examples of theoretical and practical applications of the framework. These include validation and conceptualization of constructs (e.g., performance readiness), and understanding of higher-order constructs, such as training tolerance, when monitoring training to adapt it to individual responses and effects. This proposed conceptual framework provides an overarching model that may help understand and guide the development, validation, implementation and interpretation of measures used for athlete monitoring.

Bartolomei, S, De Luca, R, and Marcora, SM. May a nonlocalized postactivation performance enhancement exist between the upper and lower body in trained men? J Strength Cond Res XX(X): 000-000, 2022-The aim of this study was to establish whether a resistance exercise for the upper body may generate a postactivation performance enhancement (PAPE) in the lower body. Thirteen resistance-trained men (age = 26.4 ± 3.3 years, body mass = 76.9 ± 6.3 kg, and height = 177.6 ± 5.2 cm) participated in the present investigation and were tested for upper-body and lower-body power (bench press throw and countermovement jump power [CMJP] tests). Subjects were also tested for maximum force and electromyographic (EMG) activation of quadriceps muscles while performing an isometric leg extension. All assessments were performed before and 8 minutes after a high-intensity (HI: 5 sets of 1 rep at 90% of 1 repetition maximum [1RM]) bench press protocol, a high-power protocol (POW: 5 sets of 1 rep at 30% of 1RM with maximum explosive intent), and a control trial (CON). Subjects performed all trials in a randomized order and on different days. A significant trial × time interaction was detected for CMJP (p = 0.049). This parameter was significantly increased following the HI protocol only (p = 0.024). A significant interaction was also noted for EMG with a significant improvement following the HI protocol (p = 0.032) and a significant decrease following the POW protocol (p = 0.020). No other significant effects were detected (p0.05). The results of this investigation indicate that a HI bench press protocol may produce a PAPE in the lower-body power and increase the neuromuscular activation of leg extensor muscles. The POW bench press protocol did not show any positive effects on lower-body performance. Athletes and practitioners may take advantage from the inclusion of upper-body HI resistance exercises throughout complex resistance workouts to improve lower-body power output.

Purpose: Professional football players experience both physical and mental fatigue (MF). The main aims of this randomized crossover study were to investigate the effect of MF on repeated-sprint ability (RSA) and the effects of both physical fatigue and MF on psychomotor vigilance. Methods: Seventeen male professional football players performed 10 maximal 20-m shuttle sprints interspaced by incomplete recovery (RSA test). Running speed, heart rate, brain oxygenation, and rating of perceived exertion were monitored during each sprint. The RSA test was preceded by either a 30-minute Stroop task to induce MF or by watching a documentary for 30 minutes (control [CON]) in a randomized counterbalanced order. Participants performed a psychomotor vigilance test at baseline, after the cognitive task (MF or CON), and after the RSA test. Results: Heart rate and rating of perceived exertion significantly increased, while running speed and brain oxygenation significantly decreased over the repeated sprints (P P = .001). Response speed during the psychomotor vigilance test declined after the RSA test in both conditions (P P = .012). Conclusions: MF does not reduce RSA. However, the results of this study suggest that physical fatigue and MF have negative and cumulative effects on psychomotor vigilance. Therefore, strategies to reduce both physical fatigue and MF should be implemented in professional football players.

Purpose This study investigated the effect of ischemic preconditioning (IP) on metaboreflex activation following dynamic leg extension exercise in a group of healthy participants. Method Seventeen healthy participants were recruited. IP and SHAM treatments (3 × 5 min cuff occlusion at 220 mmHg or 20 mmHg, respectively) were administered in a randomized order to the upper part of exercising leg’s thigh only. Muscle pain intensity (MP) and pain pressure threshold (PPT) were monitored while administrating IP and SHAM treatments. After 3 min of leg extension exercise at 70% of the maximal workload, a post-exercise muscle ischemia (PEMI) was performed to monitor the discharge group III/IV muscle afferents via metaboreflex activation. Hemodynamics were continuously recorded. MP was monitored during exercise and PEMI. Results IP significantly reduced mean arterial pressure compared to SHAM during metaboreflex activation (mean ± SD, 109.52 ± 7.25 vs. 102.36 ± 7.89 mmHg) which was probably the consequence of a reduced end diastolic volume (mean ± SD, 113.09 ± 14.25 vs. 102.42 ± 9.38 ml). MP was significantly higher during the IP compared to SHAM treatment, while no significant differences in PPT were found. MP did not change during exercise, but it was significantly lower during the PEMI following IP (5.10 ± 1.29 vs. 4.00 ± 1.54). Conclusion Our study demonstrated that IP reduces hemodynamic response during metaboreflex activation, while no effect on MP and PPT were found. The reduction in hemodynamic response was likely the consequence of a blunted venous return.

The dorsolateral prefrontal cortex (DLPFC) is a crucial brain region for inhibitory control, an executive function essential for behavioral self-regulation. Recently, inhibitory control has been shown to be important for endurance performance. Improvement in inhibitory control was found following transcranial direct current stimulation (tDCS) applied over the left DLPFC (L-DLPFC). This study examined the effect tDCS on both an inhibitory control and endurance performance in a group of healthy individuals. Twelve participants received either real tDCS (Real-tDCS) or placebo tDCS (Sham-tDCS) in randomized order. The anodal electrode was placed over the L-DLPFC while the cathodal electrode was placed above Fp2. Stimulation lasted 30 min with current intensity set at 2 mA. A Stroop test was administered to assess inhibitory control. Heart rate (HR), ratings of perceived exertion (RPE), and leg muscle pain (PAIN) were monitored during the cycling time to exhaustion (TTE) test, while blood lactate accumulation (∆B[La−]) was measured at exhaustion. Stroop task performance was improved after Real-tDCS as demonstrated by a lower number of errors for incongruent stimuli (p = 0.012). TTE was significantly longer following Real-tDCS compared to Sham-tDCS (p = 0.029, 17 ± 8 vs 15 ± 8 min), with significantly lower HR (p = 0.002) and RPE (p < 0.001), while no significant difference was found for PAIN (p > 0.224). ∆B[La−] was significantly higher at exhaustion in Real-tDCS (p = 0.040). Our findings provide preliminary evidence that tDCS with the anodal electrode over the L-DLPFC can improve both inhibitory control and endurance cycling performance in healthy individuals.

Sport training and competitions pose very high demands on the brain and not just the cardiorespiratory, metabolic, and neuromuscular systems. Therefore, sport training and competitions can be mentally as well as physically fatiguing. Furthermore, media engagements, over-analysis, and environmental instability are thought to cause mental fatigue in athletes. Both in terms of endurance performance and psychomotor performance, the negative effect of mental fatigue has been largely replicated. Moderating factors that seem to affect the effect of mental fatigue on sport performance are cognitive load of the performance task, level of training, preceding physical activity (e.g. extensive warm-up), motivation, heat, and anaerobic demand. Insight about the mechanisms underlying the negative effects of mental fatigue on sport performance is still scarce. Psychologically, it is quite clear that perception of effort during aerobic exercise is higher than normal in mentally fatigued individuals. Physiologically, further studies monitoring the possible neurophysiological alterations are highly recommended. Possible methods to counteract the negative impact of mental fatigue on sport performance can be subdivided into (1) strategies to limit mental demand before and during competitions, (2) usage of ergogenic aids and psychological strategies, and (3) training to develop resistance to mental fatigue. Eventually, research on mental fatigue in athletes may translate to other populations like soldiers and patients suffering from pathological forms of mental fatigue.

not available

Purpose Despite their widespread use in exercise physiology, time-to-exhaustion (TTE) tests present an often-overlooked challenge to researchers, which is how to computationally deal with between- and within-subject differences in exercise duration. We aimed to verify the best analysis method to overcome this problem. Methods Eleven cyclists performed an incremental test and three TTE tests differing in workload as preliminary tests. The TTEs were used to derive the individual power–duration relationship needed to set the workload (corresponding to an estimated TTE of 1200 s) for four identical experimental TTE tests. Within individuals, the four tests were subsequently rank ordered by performance. Physiological and psychological variables expected to change with performance were analysed using different methods, with the main aim being to compare the traditional “group isotime” method and a less-used “individual isotime” method. Results The four tests, ranked from the best to the worst, had a TTE of 1526 ± 332, 1425 ± 313, 1295 ± 325, and 1026 ± 265 s. Ratings of perceived exertion, minute ventilation, respiratory frequency, and affective valence were sensitive to changes in performance when their responses were analysed with the “individual isotime” method (P ηp2 > 0.144) but not when using the “group isotime” method, because the latter resulted in partial data loss. Conclusions The use of the “individual isotime” method is strongly encouraged to avoid the misinterpretation of the phenomenon under study. Important implications are not limited to constant-workload exercise, but extend to incremental exercise, which is another commonly used test of exercise tolerance.

This investigation assessed the impact of three cognitively demanding tasks on cognitive performance, subjective, and physiological indicators of mental fatigue. Following familiarization, participants completed four testing sessions, separated by 48 h. During each session, participants watched a 45-min emotionally neutral documentary (control) or completed one of the following computer tasks: Psychomotor Vigilance Task (PVT); AX-Continuous Performance Test (AX-CPT); or Stroop Task. Mental fatigue was assessed before and at regular periods for 60 min following the 45-min treatments. Cognitive performance was assessed using 3-min PVT, and task performance. Subjective assessments were conducted using the Brunel Mood Scale, and visual analog scales (VAS). Physiological indicators of mental fatigue included electroencephalography (EEG), and heart rate variability (HRV). Subjective ratings of mental fatigue increased from pre to 0-min post in all-treatments, but not the documentary (p < 0.05). Subjective fatigue (VAS) remained higher (p < 0.05) than pretreatment values for 20-, 50-, and 60-min following the PVT, Stroop, and AX-CPT respectively. The cognitively demanding tasks had unclear effects on 3-min PVT, EEG, and HRV assessments. Tasks requiring response inhibition appear to induce fatigue for longer durations than a simple vigilance task. Simple VAS appear to be the most practical method for assessing mental fatigue.

Purpose The aim of this study was to test the hypothesis that subjective thermal strain can reduce endurance performance independently from the general physiological strain normally associated with impaired endurance performance in the heat. Methods In 20 °C and 44% relative humidity, 12 endurance-trained athletes (1♀ 11♂; mean ± SD; age: 27 ± 6 y; VO2max: 61 ± 6 ml/kg/min) performed a time to exhaustion (TTE) test in two different experimental conditions: with an electric heat pad applied to the subjects' upper back (HP) and control (CON: without heat pad). In both conditions, subjects cycled to volitional exhaustion at 70% of their VO2max. Cardiorespiratory, metabolic, thermoregulatory and perceptual responses were measured throughout the TTE test and compared at 0%, 50% and 100% isotime and at exhaustion. Results TTE was reduced by 9% in HP (2092 ± 305 s) compared to CON (2292 ± 344 s; p = .023). The main effect of condition on thermal discomfort at isotime (p = .002), the effect of condition on thermal sensation at 0% isotime (p = .004) and the condition by isotime interaction on rating of perceived exertion (p = .036) indicated higher subjective thermal strain in HP compared to CON. None of the measured cardiorespiratory, metabolic and thermoregulatory variables differed significantly between conditions. Conclusion Our novel experimental manipulation (HP) was able to induce significant subjective thermal strain and reduce endurance performance in a temperate environment without inducing the general physiological strain normally associated with impaired endurance performance in the heat. These results suggest that subjective thermal strain is an important and independent mediator of the heat-induced impairment in endurance performance.

© 2019 Human Kinetics, Inc. Exercise is a stressor that induces various psychophysiological responses, which mediate cellular adaptations in many organ systems. To maximize this adaptive response, coaches and scientists need to control the stress applied to the athlete at the individual level. To achieve this, precise control and manipulation of the training load are required. In 2003, the authors introduced a theoretical framework to define and conceptualize the measurable constructs of the training process. They described training load as having 2 measurable components: internal and external load. The aim of this commentary is to extend, clarify, and refine both the theoretical framework and the definitions of internal and external training load to avoid misinterpretation of this concept.

Endurance athletes draw on several sources of self-efficacy, but there is a limited understanding of what information within these sources specifically contributes towards self-efficacy. An increased understanding and awareness of the sources of self-efficacy for endurance performance would allow the design and delivery of more effective self-efficacy interventions. The aim of the current study was to identify sources of self-efficacy specific to the endurance sport domain. Semi-structured interviews were conducted with twelve experienced competitive endurance athletes who had been competing in their endurance sport for an average of 12.2 ± 6.25 years. Interviews were recorded, transcribed verbatim, and analysed using deductive thematic analysis. Past performance experiences, physiological states, social/verbal persuasions and emotional states were generated as initial themes. Within these themes, six sub-themes were identified: cumulative experiences, challenge and adversity, physical familiarity, social support, self-talk, and doubt and worry. Our results indicate that endurance athletes make use of several sources of self-efficacy in the formation and maintenance of their self-efficacy beliefs. Specifically, the culmination of experiences, experiences of overcoming challenge and adversity, and a sense of physical familiarity appeared to key sources in the endurance sport domain. © 2018, © 2018 International Society of Sport Psychology.

Background: Dependence in self-care activities among older women has been previously evaluated through performance-based tests. However, these tests have presented inability to accurately distinguish between dependent and independent older adults in performing activities of daily living. Aim: To examine the validity, reliability, and diagnostic accuracy of rating of perceived exertion (RPE) to identify dependence in performing self-care activities in older women. Methods: Thirty-five older women performed two different constant-load tasks (walking on treadmill at 4 km/h for five minutes and arm curls with two kg for one minute), reporting RPE at the end, in four sessions. Performance-based tests (30-second chair stand and 6-minute walk) were also evaluated. Katz Index and Lawton and Brody questionnaires were applied to evaluate the dependence level in performing basic and instrumental activities of daily living. Results: RPE was greater on the first session (RPE 14 ± 2) than second session (RPE 13 ± 2), while it was similar through other sessions, with high values of intraclass coefficient correlation (0.96–0.99). Basic activities of daily living and instrumental activities of daily living presented high correlations with RPE measures (0.75–0.82), whereas performance-based tests presented moderate correlations (0.47–0.59). RPE responses explained the most variance in identifying dependence in self-care activities and presented high diagnostic accuracy to differentiate dependent from independent older women. So the hypotheses had been confirmed that RPE responses in constant-load exercise are better predictors of dependence in self-care activities than performance-based tests. Conclusions: RPE of constant-load physical tasks was valid, reliable, and accurate in identifying dependence in performing self-care activities in older women; therefore, it is possible to use the perceived exertion to identify dependence in performing activities of daily living in older women. © 2018, © 2018 Taylor & Francis Group, LLC.

Purpose It is well established that mental fatigue impairs performance during lab-based endurance tests lasting < 45 min. However, the effects of mental fatigue on longer-duration endurance events and in field settings are unknown. The aim of this study was to investigate the effect of mental fatigue on performance during a half-marathon race.Methods Forty-six male amateur runners (means ± SD: age 43.8 ± 8.6 years, V̇O2max 46.0 ± 4.1 ml/kg/min) completed an half-marathon after being randomly allocated to performing a 50-min mentally-fatiguing task (mental fatigue group) or reading magazines for 50 min (control group). Running speed, heart rate, and perceived effort were measured during the race.Results The mental fatigue group completed the half-marathon approximately four minutes slower (106.2 ± 12.4 min) than the control group (102.4 ± 10.2 min), but this difference was not statistically significant (Cohen’s d = 0.333; p = 0.265). However, equivalence was not established (t(40.88) = 0.239, p = 0.594) and equivalence testing analysis excluded a worthwhile positive effect of mental fatigue on half-marathon performance.Conclusion Due to its posttest-only design and the achievable sample size, the study did not have enough power to provide evidence that the observed 4-minute increase in half-marathon time is statistically significant. However, equivalence testing suggests that mental fatigue has no beneficial effects on half-marathon performance in male amateur runners, and harmful effects cannot be excluded. Overall, it seems prudent for endurance athletes to avoid mentally-fatiguing tasks before competitions.

Purpose It is well established that mental fatigue impairs performance during lab-based endurance tests lasting less than 45 min. However, the effects of mental fatigue on longer duration endurance events and in field settings are unknown. The aim of this study was to investigate the effect of mental fatigue on performance during a half-marathon race. Methods Forty-six male amateur runners (means ± SD: age 43.8 ± 8.6 years, $$\dot V{O_{2peak}}$$ V ˙ O 2 p e a k 46.0 ± 4.1 ml/kg/min) completed a half-marathon after being randomly allocated to performing a 50-min mentally fatiguing task (mental fatigue group) or reading magazines for 50 min (control group). Running speed, heart rate, and perceived effort were measured during the race. Results Runners in the mental fatigue group completed the half-marathon approximately 4 min slower (106.2 ± 12.4 min) than those in the control group (102.4 ± 10.2 min), but this difference was not statistically significant (Cohen’s d = 0.333; p = 0.265). However, equivalence was not established [t(40.88) = 0.239, p = 0.594] and equivalence testing analysis excluded a beneficial effect of mental fatigue on half-marathon performance. Conclusion Due to its posttest-only design and the achievable sample size, the study did not have enough power to provide evidence that the observed 4-min increase in half-marathon time is statistically significant. However, equivalence testing suggests that mental fatigue has no beneficial effect on half-marathon performance in male amateur runners, and a harmful effect cannot be excluded. Overall, it seems prudent for endurance athletes to avoid mentally fatiguing tasks before competitions.

Background and Aims: People with type 1 diabetes (T1D) experience higher rates of sleep disturbances than those without diabetes, and this can have negative implications for glycemic control. Sleep is critical for optimal athletic performance and recovery so it is important to have an understanding of factors that can influence sleep in athletes with T1D. This study investigated whether there is a relationship between i) daily training load and ii) time in glycemic ranges on sleep time of professional cyclists with T1D. Methods: Sixteen professional cyclists from Team Novo Nordisk (age 27 ± 4 y; HbA1c 6.8 ± 0.5%) used a wrist-worn actigraph device (Actiwatch Spectrum Plus, Philips Respironics, Murrysville, PA) to monitor sleep-wake activity over a 10-day training camp. Training variables (distance (km), elevation (m), work (kJ)) were used to determine a training stress score (TSS) for each day of the camp and glycemia was recorded using Dexcom, G6 (San Diego, CA). Summary statistics and correlations were run over the measured variables. Results: On average, riders spent 8.6 ± 1 h in bed with a total sleep time of 7 ± 1.3 h (6.0 ÷ 7.8). The riders cycled 115 ± 26 km with 1849 ± 1086 m of elevation gain per day, corresponding to a mean TSS of 221 ± 142. Total sleep time was negatively associated with TSS (-0.29, p=0.01). Greater time in range (4-10 mmol/l) was positively associated with sleep time (r=0.21, p=0.03), with hyperglycemia, particularly level 2 (>14 mmol/l), being negatively associated with sleep time (-0.21, p=0.03). Conclusions: We provide preliminary evidence that a greater TSS is negatively associated with total sleep time in professional athletes with T1D. Second, greater time spent in euglycemia is associated with greater sleep time, with time above target having a negative association with sleep. Further data should be collected longitudinally to strengthen these results to serve as a basis to promote better sleep hygiene practices to overcome the effects of higher training loads. Disclosure S.N. Scott: None. F.Y. Fontana: None. B. Martinez-Gonzalez: None. C.A. Hayes: Other Relationship; Self; Novo Nordisk A/S. P.H. Lagrou: None. S. Marcora: None. T. Zueger: None. C. Stettler: None.

Context: Referees’ physical and cognitive performance are important for successful officiating in team sports. There is a lack of research on cognitive performance of referees in general, and none in futsal. Purpose: To assess referees’ performance on the psychomotor vigilance task (PVT) before and after competitive futsal matches during the Football Association (FA) National Futsal League 2015/16. Methods: Fourteen futsal referees (mean [SD] age 34.3 [10.0] y) from the FA National Futsal group were included. The referees were required to undertake a 10-min PVT 60 min before the match kickoff time (pretest) and immediately after matches (posttest). They also completed the Brunel Mood Scale (BRUMS) questionnaire before the prematch PVT and after the postmatch PVT. Result: Data were analyzed by paired t tests comparing prematch and postmatch results. There was a significant difference in BRUMS parameters vigor (9.5 [2.5] prematch vs 6.3 [2.4] postmatch, P = .001) and fatigue (1.4 [1.3] prematch vs 5.6 [3.1] postmatch, P P = .023). Conclusions: The present results show, contrary to the authors’ initial hypothesis, that psychomotor performance is improved as opposed to decreased after a single match. The postmatch improvement suggests that exercise can acutely enhance cognitive performance, which could be used to inform warm-up practices (eg, optimal duration and intensity) geared toward optimizing referees’ cognitive performance during matches.

Introduction: Mental fatigue is associated with a shift of electroencephalography (EEG) power towards low-frequency bands [theta, alpha(a)], which is suggested to be related to a decrease in the level of arousal. In addition a decrease in the amplitude of event related brain potentials like P2 (i.e. an index of activity engaged in selection of relevant information) is also observed with the occurrence of mental fatigue. In order to further elucidate the role of these brain alterations in the occurrence of mental fatigue we sought to prevent them with a caffeine-maltodextrin (CAF-MALT) mouth rinse intervention during a mentally fatiguing task. Methods: Ten active healthy males (age: 23±2y, physical activity: 7.3±4.3h/week), which were all low CAF users (101±97mg/day), performed two experimental trials in a randomized crossover order. In both trials participants first completed a baseline Flanker task (3min). Next they performed a 90-min mentally fatiguing task (Stroop task), that was immediately followed by aFlanker task. Before the start and after each 12.5% of the Stroop task (8 blocks of 11min) subjects received either a CAF-MALT mouth rinse (MR; 0.3g/25ml CAF; 1.6g/25ml MALT) or placebo (PLAC; 25ml artificial saliva). To measure mental fatigue, physiological and psychological measures were assessed. EEG (32 active electrodes) was applied throughout the experiment to record brain activity. Normality was checked, repeated measure ANOVAs were employed to observe interaction and/or main effects of condition and/or time. Follow up tests were performed where necessary (p

Since respiratory frequency (fR) has been proposed as a good marker of physical effort, furthering the understanding of how fR is regulated during exercise is of great importance. We manipulated recovery intensity and exercise duration during high-intensity interval training (HIIT) to test the hypothesis that fast inputs (including central command) contribute more than metabolic stimuli to fR regulation. Seven male cyclists performed an incremental test, a 10 min and a 20 min continuous time trial (TT) as preliminary tests. Subsequently, recovery intensity and exercise duration were manipulated during HIIT (30 s work and 30 s active recovery) by performing four 10 min and one 20 min trial (recovery intensities: 85%, 70%, 55% and 30% of the 10 min TT mean workload; 85% of the 20 min TT mean workload). The work intensity of the HIIT sessions was self-paced by participants to achieve the best performance possible. When manipulating recovery intensity, fR, but not tidal volume (VT), showed a fast response to the alternation of the work and recovery phases, proportional to the extent of workload variations. No association between fR and gas exchange responses was observed. When manipulating exercise duration, fR and Rating of Perceived Exertion (RPE) were dissociated from VT, VCO2 and VO2 responses. Overall, RPE was strongly correlated with fR (r = 0.87; P

This chapter provides the reader with an introduction to endurance performance and a brief introduction to traditional physiological models of endurance performance, the central fatigue model, the central governor model, and the psychobiological model. We will also cover the role of psychological determinants of endurance performance, such as stressors related to training and competition, as well as motivation, followed by an overview of what the reader can expect from the book.

Purpose: To investigate the impact of twice-daily inhalation of 100 µg of salmeterol (SAL) or 12 µg of formoterol (FOR) in addition to a strength- and power-training program over a 5-wk period on a 30-m sprint, strength, power, mood, stress, and skinfold thickness. Methods: In a randomized, single-blind study, 23 male and 15 female nonasthmatic, recreationally active individuals were recruited (mean [SD] age 26.3 [5.4] y, weight 76.2 [11.5] kg, height 176.9 [8.5] cm). Participants completed 3 standardized whole-body strength- and power-training sessions per week for 5 wk during which they were assigned to an SAL, FOR, or placebo group. Participants used their inhaler twice per day as instructed and completed assessments of sprint, strength, and power at baseline and 1 wk after cessation of the training program. The assessments included a 30-m sprint, vertical jump, 1-repetition-maximum (1RM) bench press, 1RM leg press, peak torque flexion and extension, anthropometric evaluation, and Rest-Q questionnaires. Results: After 5 wk of strength and power training, 30-m sprint time reduced in the FOR (0.29 [0.11] s, P = .049) and SAL (0.35 [0.05] s, P = .040) groups compared with placebo (+0.01 [0.11] s). No significant change was found in other assessments of strength, mood, or skinfold thickness. Conclusions: When strength and power training are combined with the inhalation of FOR or SAL over a 5-wk period, moderately trained individuals experience an improvement in 30-m sprint performance.

Background: Stimulation of the right and left anterior insular cortex, increases and decreases the cardiovascular response respectively, thus indicating the brain’s lateralization of the neural control of circulation. Previous experiments have demonstrated that transcranial direct current stimulation (tDCS) modulates the autonomic cardiovascular control when applied over the temporal cortex. Given the importance of neural control for a normal hemodynamic response, and the potential for the use of tDCS in the treatment of cardiovascular diseases, this study investigated whether tDCS was capable of modulating autonomic regulation.\ud \ud Methods: Cardiovascular response was monitored during a post-exercise muscle ischemia (PEMI) test, which is well-documented to increase sympathetic drive. A group of 12 healthy participants performed a PEMI test in a control (CON), sham (Sham) and two different experimental sessions where the anodal electrode was applied over the left temporal cortex and right temporal cortex with the cathodal electrode placed over the contralateral supraorbital area. Stimulation lasted 20 min at 2 mA. The hemodynamic profile was measured during a PEMI test. The cardiovascular parameters were continuously measured with a transthoracic bio-impedance device both during the PEMI test and during tDCS.\ud \ud Results: None of the subjects presented any side effects during or after tDCS stimulation. A consistent cardiovascular response during PEMI test was observed in all conditions. Statistical analysis did not find any significant interaction and any significant main effect of condition on cardiovascular parameters (all ps > 0.316) after tDCS. No statistical differences regarding the hemodynamic responses were found between conditions and time during tDCS stimulation (p > 0.05).\ud \ud Discussion: This is the first study comparing the cardiovascular response after tDCS stimulation of left and right TC both during exercise and at rest. The results of the current study suggest that anodal tDCS of the left and right TC does not affect functional cardiovascular response during exercise PEMI test and during tDCS. In light of the present and previous findings, the effect of tDCS on the cardiovascular response remains inconclusive.

Purpose: It has recently been reported that professional road cyclists have superior inhibitory control and resistance to mental fatigue compared to recreational cyclists. We sought to assess whether badminton players also have superior executive functions and whether they are more resistant to mental fatigue than controls on a visuomotor task. Methods: Eleven healthy controls (mean ± SD; age: 25±4y; 6 females, 5 males) and nine healthy badminton players (age: 23±3y; 4 females, 5 males) performed two experimental trials in a randomized crossover order. Participants completed a baseline visuomotor task, followed by a Flanker task. Next, they performed either a 90-min Stroop task (MF) or watched a 90-min documentary (CON). Immediately thereafter, the Flanker task and the visuomotor task were completed again. Multiple physiological and psychological measures were assessed during the protocol. Results: Badminton players’ and controls’ accuracy during the Stroop task decreased over time (p = 0.023). Subjectively, both groups perceived the Stroop task as more mentally demanding than the documentary (p < 0.001). In addition, higher mental fatigue was perceived in MF compared to CON, independently from group (p = 0.029). In the visuomotor task, controls as well as badminton players reacted significantly slower to the complex stimuli when mentally fatigued (~7%; p < 0.001). Badminton players (1109 ± 251 ms) outperformed controls (1299 ± 227 ms; p = 0.022) in the visuomotor task. However, this was not the case in the Stroop and Flanker task; in terms of accuracy and response time, badminton players and controls performed similarly. Conclusion: These findings provide evidence that badminton players have better visuomotor response time than controls. However, they do not seem to be more resistant to the negative effects of mental fatigue on open skill-visuomotor performance. Furthermore, our study suggests that cognitive tasks with a larger motor component, such as our visuomotor task, are more sensitive to the negative effects of mental fatigue than traditional cognitive tasks (e.g. Flanker task) that have a very small motor component. © 2019

Fatigue is a complex state with multiple physiological and psychological origins. However, fatigue in soccer has traditionally been investigated from a physiological perspective, with little emphasis on the cognitive demands of competition. These cognitive demands may induce mental fatigue, which could contribute to the fatigue-related performance decrements observed during and after soccer matches. Recent research investigating the relationship between mental fatigue and soccer-specific performance supports this suggestion. This leading article provides an overview of the research in this emerging field, outlining the impact of mental fatigue on soccer-specific physical, technical, decision-making, and tactical performances. The second half of this review provides directions for future research in response to the limitations of the existing research. Emphasis is placed on translating the current body of knowledge into practical applications and developing a greater understanding of the mechanisms underpinning the negative impact of mental fatigue on soccer performance. A conceptual model is presented to help direct this future research. © 2018, Springer International Publishing AG, part of Springer Nature.

Self-efficacy is likely to be an important psychological construct for endurance sport performance. Research into the role of self-efficacy, however, is limited as there is currently no validated measure of endurance sport self-efficacy. Consequently, the purpose of the present research was to develop and validate the Endurance Sport Self-Efficacy Scale (ESSES). In Study 1, an initial item pool was developed following a review of the literature. These items were then examined for content validity by an expert panel. In Study 2, the resultant 18 items were subjected to exploratory factor analyses. These analyses provided support for a unidimensional scale comprised of 11 items. Study 2 also provided evidence for the ESSES's convergent validity. In Study 3, using confirmatory factor analyses, further support was found for the 11-item unidimensional structure. Study 3 also provided evidence for the ESSES's convergent and concurrent validity. The present findings provide initial evidence that the ESSES is a valid and reliable measure of self-efficacy beliefs in endurance sports.

This study examined the effects of strategic, motivational self-talk for runners completing a 60-mile, overnight ultramarathon using a randomized, controlled experiment. Data were collected before, during, and after an annual ultramarathon. Twenty-nine ultramarathon runners were randomly allocated to a motivational self-talk group or an alternative control group. A condition-by-time mixed ANOVA indicated that learning to use motivational self-talk did not affect preevent self-efficacy or perceived control. A t-test and magnitude-based inference indicated that motivational self-talk did not affect performance. Nevertheless, follow-up data suggested that most participants found the intervention helpful and continued to use it six months after their research commitment, particularly in endurance events and to a lesser extent in training. Participants continued to use self-talk to cope with exertion, as well as other stressors such as blister discomfort and adverse conditions. Suggestions are offered for future research examining the effects of psychological interventions on performance in endurance events.

This study aimed to identify psychological demands that are commonly experienced by endurance athletes so that these demands could inform the design of performance-enhancing psychological interventions for endurance athletes. Focus group interviews were conducted with 30 recreational endurance athletes of various sports (running, cycling, and triathlon), distances, and competitive levels to explore the psychological demands of training, competition preparation, and competition participation. An inductive thematic analysis was used to identify psychological demands that were experienced across sports, distances, and competitive levels. Seven themes captured demands that were commonly experienced away from the competitive environment (time investment and lifestyle sacrifices, commitment to training sessions, concerns about optimising training, and exercise sensations during training), preceding an endurance event (pre-event stressors), or during an event (exercise sensations, optimising pacing, and remaining focused despite adversity). Interventions that could be delivered to recreational athletes, who do not typically have access to a sport psychologist, are suggested. Experimental research examining the efficacy of interventions that help endurance athletes to cope with the reported psychological demands is encouraged. © 2016, © 2016 International Society of Sport Psychology.

The capacity to sustain high-intensity aerobic exercise is essential for endurance performance. Therefore, it is important to understand what is the factor limiting time to exhaustion (TTE) in healthy and fit adults. In Study 1, maximal voluntary cycling power (MVCP) was measured in 11 volunteers before and immediately after a high-intensity TTE test on cycle ergometer. Cadence was 60 rpm in both the MVCP and TTE tests. Despite a 35% loss in MVCP, power produced during the final MVCP test (mean ± SD 469 ± 111 W) was significantly higher than the power required by the TTE test (269 ± 55 W) (P < 0.001). In Study 2, 12 participants performed a cold pressor test (CPT) to the limit of tolerance followed by a high-intensity TTE test on cycle ergometer. Ratings of pain unpleasantness (RPU) during the TTE test were anchored to the unpleasantness of pain experienced during the CPT. On average, the RPU was 9.7 ± 0.4 at completion of the CPT and 5.0 ± 0.9 at exhaustion during the TTE test. The difference between these two ratings of pain unpleasantness was statistically significant (P < 0.001). In both Studies 1 and 2, the slope of the rating of perceived exertion (RPE) during the TTE test correlated significantly with TTE (r = –0.75 and –0.83, P < 0.01). Results of this two-part investigation suggest that perception of effort, rather than severe locomotor muscle fatigue or intolerably unpleasant muscle pain, is the cardinal exercise stopper during high-intensity aerobic exercise. © 2018 Elsevier B.V.

Background Caffeine has a well-established effect on reaction times (RTs) but the neurocognitive mechanisms underlying this are unclear. Methods In the present study, 15 female participants performed an oddball task after ingesting caffeine or a placebo, and electroencephalographic data were obtained. Single-trial P3b latencies locked to the stimulus and to the response were extracted and mediation models were fitted to the data to test whether caffeine’s effect on RTs was mediated by its effect on either type of P3b latencies. Results Stimulus-locked latencies showed clear evidence of mediation, with approximately a third of the effect of caffeine on RTs running through the processes measured by stimulus-locked latencies. Caffeine did not affect response-locked latencies, so could not mediate the effect. Discussion These findings are consistent with caffeine’s effect on RTs being a result of its effect on perceptual-attentional processes, rather than motor processes. The study is the first to apply mediation analysis to single-trial P3b data and this technique holds promise for mental chronometric studies into the effects of psychopharmacological agents. The R code for performing the single trial analysis and mediation analysis are included as supplementary materials. Electronic supplementary material The online version of this article (10.1007/s00213-017-4790-7) contains supplementary material, which is available to authorized users.

Purpose Time to exhaustion (TTE) tests used in the determination of critical power (CP) and curvature constant (W′) of the power–duration relationship are strongly influenced by the perception of effort (PE). This study aimed to investigate whether manipulation of the PE alters the CP and W′. Methods Eleven trained cyclists completed a series of TTE tests to establish CP and W′ under two conditions, following a mentally fatiguing (MF), or a control (CON) task. Both cognitive tasks lasted 30 min followed by a TTE test. Ratings of PE and heart rate (HR) were measured during each TTE. Blood lactate was taken pre and post each TTE test. Ratings of perceived mental and physical fatigue were taken pre- and post-cognitive task, and following each TTE test. Results Perceived MF significantly increased as a result of the MF task compared to baseline and the CON task (P P > 0.05). PE was significantly higher during TTE in the MF condition (P P P > 0.05). Neither cognitive task induced any change in CP (MF 253 ± 51 vs. CON 247 ± 58W; P > 0.05), although W′ was significantly reduced in the MF condition (MF 22.8 ± 4.5 vs. CON 29.3 ± 6.3 kJ; P Conclusion MF has no effect of CP, but reduces the W′ in trained cyclists. Lower lactate accumulation during TTE tests following MF suggests that cyclists were not able to fully expend W′ even though they exercised to volitional exhaustion.

BACKGROUND: Transcranial direct current stimulation (tDCS) has been used to enhance endurance performance but its precise mechanisms and effects remain unknown.\ud \ud OBJECTIVE: To investigate the effect of bilateral tDCS on neuromuscular function and performance during a cycling time to task failure (TTF) test.\ud \ud METHODS: Twelve participants in randomized order received a placebo tDCS (SHAM) or real tDCS with two cathodes (CATHODAL) or two anodes (ANODAL) over bilateral motor cortices and the opposite electrode pair over the ipsilateral shoulders. Each session lasted 10 min and current was set at 2 mA. Neuromuscular assessment was performed before and after tDCS and was followed by a cycling time to task failure (TTF) test. Heart rate (HR), ratings of perceived exertion (RPE), leg muscle pain (PAIN) and blood lactate accumulation (ΔB[La-]) in response to the cycling TTF test were measured.\ud \ud RESULTS: Corticospinal excitability increased in the ANODAL condition (P < 0.001) while none of the other neuromuscular parameters showed any change. Neuromuscular parameters did not change in the SHAM and CATHODAL conditions. TTF was significantly longer in the ANODAL (P = 0.003) compared to CATHODAL and SHAM conditions (12.61 ± 4.65 min; 10.61 ± 4.34 min; 10.21 ± 3.47 min respectively), with significantly lower RPE and higher ΔB[La-] (P < 0.001). No differences between conditions were found for HR (P = 0.803) and PAIN during the cycling TTF test (P = 0.305).\ud \ud CONCLUSION: Our findings demonstrate that tDCS with the anode over both motor cortices using a bilateral extracephalic reference improves endurance performance.

Purpose: Transcranial direct current stimulation (tDCS) provides a new exciting means to investigate the role of the brain during exercise. However, this technique is not widely used in exercise science, with little known regarding effective electrode montages. This study investigated whether tDCS of the motor cortex (M1) would elicit an analgesic response to exercise-induced pain (EIP). Methods: Nine participants completed a VO2max test and three time to exhaustion (TTE) tasks on separate days following either 10 min 2 mA tDCS of the M1, a sham or a control. Additionally, seven participants completed 3 cold pressor tests (CPT) following the same experimental conditions (tDCS, SHAM, CON). Using a well-established tDCS protocol, tDCS was delivered by placing the anodal electrode above the left M1 with the cathodal electrode above dorsolateral right prefrontal cortex. Gas exchange, blood lactate, EIP and ratings of perceived exertion (RPE) were monitored during the TTE test. Perceived pain was recorded during the CPT. Results: During the TTE, no significant differences in time to exhaustion, RPE or EIP were found between conditions. However, during the CPT, perceived pain was significantly (P

Background: Mental fatigue is a psychobiological state caused by prolonged periods of demanding cognitive activity. It has recently been suggested that mental fatigue can affect physical performance. Objective: Our objective was to evaluate the literature on impairment of physical performance due to mental fatigue and to create an overview of the potential factors underlying this effect. Methods: Two electronic databases, PubMed and Web of Science (until 28 April 2016), were searched for studies designed to test whether mental fatigue influenced performance of a physical task or influenced physiological and/or perceptual responses during the physical task. Studies using short (

Purpose Mental fatigue is a psychobiological state caused by prolonged periods of demanding cognitive activity and has been observed to decrease time trial (TT) endurance performance by ∼3.5% in normal ambient temperatures. Recently, it has been suggested that heat may augment the negative effect of mental fatigue on cognitive performance, raising the question whether it may also amplify the effect of mental fatigue on TT performance. Methods In 30°C and 30% relative humidity, 10 endurance-trained male athletes (mean ± SD; age = 22 ± 3 yr, W max = 332 ± 41 W) completed two experimental conditions: intervention (I; 45-min Stroop task) and control (C; 45-min documentary). Pre- and postintervention/control, cognitive performance was followed up with a 5-min Flanker task. Thereafter, subjects cycled for 45 min at a fixed pace equal to 60% W max, immediately followed by a self-paced TT in which they had to produce a fixed amount of work (equal to cycling 15 min at 80% W max) as fast as possible. Results Self-reported mental fatigue was significantly higher after I compared with C (P < 0.05). Moreover EEG measures also indicated the occurrence of mental fatigue during the Stroop (P < 0.05). TT did not differ between conditions (I = 906 ± 30 s, C = 916 ± 29 s). Throughout exercise, physiological (HR, blood lactate, core, and skin temperature) and perceptual measures (perception of effort and thermal sensation) were not affected by mental fatigue. Conclusion No negative effects of mild mental fatigue were observed on performance and the physiological and perceptual responses to endurance exercise in the heat. Most plausibly, mild mental fatigue does not reduce endurance performance when the brain is already stressed by a hot environment. © 2017 by the American College of Sports Medicine.

PURPOSE: The psychobiological model of endurance performance proposes that the perception of effort is the ultimate determinant of endurance performance. Therefore, any physiological or psychological factor affecting the perception of effort will affect endurance performance. Accordingly, this novel study investigated the effects of a frequently used psychological strategy, motivational self-talk (ST), on RPE and endurance performance. METHODS: In a randomized between-group pretest-posttest design, 24 participants (mean ± SD age = 24.6 ± 7.5 yr, V̇O2max = 52.3 ± 8.7 mL·kg·min) performed two constant-load (80% peak power output) cycling time-to-exhaustion (TTE) tests, punctuated by a 2-wk ST intervention or a control phase. RESULTS: A group (ST vs Control) × test (pretest vs posttest) mixed-model ANOVA revealed that ST significantly enhanced TTE test from pretest to posttest (637 ± 210 vs 750 ± 295 s, P < 0.05) with no change in the control group (486 ± 157 vs 474 ± 169 s). Moreover, a group × test × isotime (0%, 50%, and 100%) mixed-model ANOVA revealed a significant interaction for RPE, with follow-up tests showing that motivational self-talk significantly reduced RPE at 50% isotime (7.3 ± 0.6 vs 6.4 ± 0.8, P < 0.05), with no significant difference in the control group (6.9 ± 1.9 vs 7.0 ± 1.7). CONCLUSIONS: This study is the first to demonstrate that ST significantly reduces RPE and enhances endurance performance. The findings support the psychobiological model of endurance performance and illustrate that psychobiological interventions designed to specifically target favorable changes in the perception of effort are beneficial to endurance performance. Consequently, this psychobiological model offers an important and novel perspective for future research investigations. © 2014 by the American college of Sports Medicine.

International audience; Transcranial direct current stimulation (tDCS) can increase cortical excitability of a targeted brain area, which may affect endurance exercise performance. However, optimal electrode placement for tDCS remains unclear. We tested the effect of two different tDCS electrode montages for improving exercise performance. Nine subjects underwent a control (CON), placebo (SHAM) and two different tDCS montage sessions in a randomized design. In one tDCS session, the anodal electrode was placed over the left motor cortex and the cathodal on contralateral forehead (HEAD), while for the other montage the anodal electrode was placed over the left motor cortex and cathodal electrode above the shoulder (SHOULDER). tDCS was delivered for 10 min at 2.0 mA, after which participants performed an isometric time to exhaustion (TTE) test of the right knee extensors. Peripheral and central neuromuscular parameters were assessed at baseline, after tDCS application and after TTE. Heart rate (HR), ratings of perceived exertion (RPE), and leg muscle exercise-induced muscle pain (PAIN) were monitored during the TTE. TTE was longer and RPE lower in the SHOULDER condition (P < 0.05). Central and peripheral parameters, and HR and PAIN did not present any differences between conditions after tDCS stimulation (P > 0.05). In all conditions maximal voluntary contraction (MVC) significantly decreased after the TTE (P < 0.05) while motor evoked potential area (MEP) increased after TTE (P < 0.05). These findings demonstrate that SHOULDER montage is more effective than HEAD montage to improve endurance performance, likely through avoiding the negative effects of the cathode on excitability. (C) 2016 The Author(s). Published by Elsevier Ltd on behalf of IBRO.

The V.O2 slow component (V.O2sc) that develops during high-intensity aerobic exercise is thought to be strongly associated with locomotor muscle fatigue. We sought to experimentally test this hypothesis by pre-fatiguing the locomotor muscles used during subsequent high-intensity cycling exercise. Over two separate visits, eight healthy male participants were asked to either perform a non-metabolically stressful 100 intermittent drop-jumps protocol (pre-fatigue condition) or rest for 33 min (control condition) according to a random and counterbalanced order. Locomotor muscle fatigue was quantified with 6-s maximal sprints at a fixed pedaling cadence of 90 rev·min-1. Oxygen kinetics and other responses (heart rate, capillary blood lactate concentration and rating of perceived exertion, RPE) were measured during two subsequent bouts of 6 min cycling exercise at 50% of the delta between the lactate threshold and V.O2max determined during a preliminary incremental exercise test. All tests were performed on the same cycle ergometer. Despite significant locomotor muscle fatigue (P = 0.03), the V.O2sc was not significantly different between the pre-fatigue (464 ± 301 mL·min-1) and the control (556 ± 223 mL·min-1) condition (P = 0.50). Blood lactate response was not significantly different between conditions (P = 0.48) but RPE was significantly higher following the pre-fatiguing exercise protocol compared with the control condition (P < 0.01) suggesting higher muscle recruitment. These results demonstrate experimentally that locomotor muscle fatigue does not significantly alter the V.O2 kinetic response to high intensity aerobic exercise, and challenge the hypothesis that the V.O2sc is strongly associated with locomotor muscle fatigue. © 2016 Hopker, Caporaso, Azzalin, Carpenter and Marcora.