Brain Endurance Training Improves Dynamic Calisthenic Exercise and Benefits Novel Exercise and Cognitive Performance: Evidence of Performance Enhancement and Near Transfer of Training.

ABSTRACT: Dallaway, N, Mortimer, H, Gore, A, and Ring, C. Brain endurance training improves dynamic calisthenic exercise and benefits novel exercise and cognitive performance: Evidence of performance enhancement and near transfer of training. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this dual study was to evaluate whether brain endurance training (BET)-a mental fatigue countermeasure involving physical and cognitive training-enhanced exercise compared with physical training alone. Two studies (N = 29) used a pretest/training/posttest design, with participants randomized to BET or control groups. During testing, participants performed calisthenic exercises (study 1: press-ups, wall sit, and plank; study 2: burpees, jump squats, leg raises, press-ups, and plank) to failure before and after completing 20-minute cognitive tasks (study 1: memory updating; study 2: memory updating, response inhibition, and nonexecutive functions). Training comprised 3 sessions per week for 4 weeks. In study 1 training sessions, participants completed 2 submaximal exercise sets; each exercise was followed by a 3-minute cognitive task with high (BET) or low (control) cognitive loads. In study 2 training sessions, participants completed 1 submaximal exercise set; after 12-minute cognitive tasks (BET) or rest (control), each exercise was preceded by a 3-minute cognitive task (BET) or rest (control). These cognitive tasks involved response inhibition and memory updating. Performance (exercise repetitions/duration), perceived exertion, and mental fatigue were assessed. In pretesting, exercise performance was matched between groups. In posttesting, BET groups performed more dynamic exercises than control groups but the same number of static exercises. Cognitive task performance was either greater for BET or not different between groups. Neither perceived exertion nor mental fatigue differed between groups and tests. Brain endurance training enhanced dynamic but not static calisthenic exercise performance compared with physical training alongside near transfer of training benefits for novel physical and cognitive task performance.

Some pressures are more equal than others: Effects of isolated pressure on performance.

It is commonly assumed that performance is impaired by pressure and that different types of individual situational factors can produce equivalent pressure. Our aim was to explore the psychophysiological effects of pressure to test this assumption. Eighty-one novices completed a golf putting task under control and eight individual pressure conditions: time, difficulty, video, team, goal, fame, shame, and distraction. Performance was measured by the number of holed putts and ball-hole distance. Psychological, physiological and kinematic measures were collected. Performance was impaired by time and difficulty conditions but improved by team, goal and shame conditions compared to control. Perceived pressure and effort were higher than control in all conditions except distraction. Conscious processing was greater than control in all conditions except distraction and time constraint. Heart rate was faster with time, team, fame and shame. Heart rate variability and muscle activity were largely unaffected. Putter kinematics provided evidence of swing profiles slowing and/or becoming constrained in conditions where conscious processing increased, while the swing became faster in the time-pressure condition where conscious processing was decreased. Taken together, these results reveal heterogenous effects of pressure on performance, with performance impaired, unaffected, and improved by individual pressure situations. Similarly, heterogeneity characterized the effects of pressure on psychological, physiological and kinematic responses associated with task performance. In sum, the evidence challenges the standard tacit assumptions about the pressure-performance relationship in sport.

Mental fatigue impairs repeated sprint and jump performance in team sport athletes.

OBJECTIVES: We tested whether mental fatigue (MF), induced by a cognitively-demanding task, would impair repeated sprint ability (RSA) and repeated jump ability (RJA) performance, and whether physical fatigue and MF would impair psychomotor vigilance. DESIGN: Randomized within-participant design. METHODS: After establishing baseline peak countermovement jump (CMJ), 18 male participants performed 12 maximal 20-m (10-m linear + 10-m directional) repeated sprints (RSA random test) followed by 12 maximal repeated CMJs (RJA test) subsequent to 30-min Stroop task (MF) or a documentary (Control). Peak and mean running time and height, percent decrement score (Sdec), blood lactate, heart rate and RPE were measured for CMJ, RSA, and RJA tests. MF (M-VAS) and psychomotor vigilance [psychomotor vigilance test (PVT)] were measured at baseline, after each condition, and after the RSA/RJA tests. RESULTS: Compared to Control, the Stroop task elevated MF (p = .001), RPE ratings (all p < .031), and mean and Sdec performance in directional (but not linear) RSA (all p < .032) and RJA tests (all p < .034). PVT score worsened after Stroop task (p = .011) but not Control, declined after RSA/RJA tests in both conditions (all p < .023) and was lower in the MF condition (p = .029). No condition differences were noted for peak (CMJ, RSA and RJA tests) performance, blood lactate, and heart rate. CONCLUSIONS: MF impairs directional RSA, and RJA performance. This impairment was linked with increased RPE and without physiological changes. The progressive impairment in PVT score suggests a cumulatively negative effect of mental and physical fatigue on psychomotor vigilance.

Effects of task difficulty on performance and event-related bradycardia during preparation for action.

The slowing of heart rate prior to movement onset has been presented as a marker of task-related cognitive processing and linked with performance accuracy. Here we examined this event-related bradycardia and task performance as a function of task difficulty. Forty experienced golfers completed a series of golf putting conditions that manipulated task difficulty by varying target distance, target size, and surface contour. Performance was measured by the number of holed putts and finishing distance from the hole. Physiological activity was recorded throughout. Analyses confirmed that performance varied as a function of task difficulty, worsening with longer distances to target, smaller targets, and sloping paths to target. Task difficulty also impacted the cardiac response, including the rate of heart rate deceleration, change in heart rate, and heart rate at impact. These heart rate metrics were found to correlate with performance strongly, moderately, and weakly, respectively. In conclusion, heart rate deceleration in the moments preceding movement onset was affected by task difficulty. Features of this cardiac deceleration pattern were characteristic of successful performance. Our findings are discussed in terms of the role of cognitive and motor processes during the execution of complex motor skills.

Effects of Stroop task duration on subsequent cognitive and physical performance.

The strength model of self-control purports to explain why brief cognitive response inhibition tasks impair subsequent isometric handgrip endurance. According to the model, ego depleting tasks requiring self-control resources impair performance on subsequent tasks that also require self-control resources. However, several lines of evidence challenge this model, including evidence of improved exercise performance following longer cognitive tasks. Our study investigated the effects of cognitive task duration on (1) subsequent physical endurance performance, (2) concurrent cognitive task performance, and (3) subsequent novel cognitive task performance. Adopting an experimental design, with Stroop task type (incongruent, congruent) and duration (5, 10, 20 min) as between-participant factors, participants (N = 180) completed a color word Stroop task, an isometric handgrip to exhaustion task, and a novel 5-min incongruent number word Stroop task. In the handgrip task, endurance performance was worse following incongruent word Stroop than congruent word Stroop for 10-min tasks but not 5-min and 20-min tasks. In the word Stroop task, accuracy was lower and speed was slower following incongruent word Stroop than congruent word Stroop. Importantly, reaction times improved with longer task durations. In the novel number Stroop task, accuracy was higher following incongruent word Stroop than congruent word Stroop. In conclusion, the finding that the ego depletion effect was moderated by cognitive task duration is better explained by the expected value of control model than the strength model.

A national anti-doping education programme reduces doping susceptibility in British athletes.

The World Anti-Doping Agency's International Standard for Education instructs that national and international sport organisations evaluate their education programmes. We addressed this directive by examining the effectiveness of a national anti-doping programme. Athletes (N = 302, 41% female) completed measures of doping susceptibility, intention to use dietary supplements, Spirit of Sport and moral values, anti-doping knowledge and practice, and whistleblowing, prior-to and three-months after attending an anti-doping education programme. At three-month follow-up, athletes reported decreased doping susceptibility and intention to use dietary supplements coupled with increased importance of values, anti-doping knowledge, anti-doping practice and whistleblowing. Within-participant, moderated-mediation analyses revealed that programme-related changes in doping susceptibility were indirectly related to changes in intention to use dietary supplements, and, that this indirect relationship was moderated by moral values. These findings confirm the effectiveness of a national anti-doping education programme and highlight the contribution of dietary supplement use and personal values to changes in doping susceptibility.

Are dietary supplement users more likely to dope than non-users?: A systematic review and meta-analysis.

In the past decade, a body of evidence has reported that dietary supplement use is related to prohibited performance enhancing substance use (i.e., doping). To help international and national sport organisations understand the degree to which dietary supplement use is related to doping, the objectives of this systematic review and meta-analysis were to 1) compare the prevalence of doping between dietary supplement users and non-users and 2) identify whether supplement use is related to doping social cognitive factors. We searched for studies sampling athletes and that measured both dietary supplement use and doping in EMBASE, MEDLINE, PsychINFO, CINAHL and SPORTDiscus from database creation to May 2022. Risk of bias was assessed using JBI Critical Appraisal Checklist for cross-sectional studies and the STROBE checklist. Twenty-six cross-sectional studies, involving 13,296 athletes were included. Random-effect models revealed that doping was 2.74 (95% CI=2.10 to 3.57) times more prevalent in dietary supplement users (pooled prevalence = 14.7%) than non-users (6.7%), and that users reported stronger doping intentions (r=0.26, 0.18 to 0.34) and attitudes (r=0.21, 0.13 to 0.28) compared to non-users. Preliminary evidence also suggests that dietary supplement users were less likely to dope if they were more task oriented and had a stronger sense of morality. Results of the review are limited by the cross-sectional design used in all studies and lack of consistency in measurement of dietary supplement use and doping. Data indicate that athletes using dietary supplements are more likely to self-report doping Anti-doping policy should, therefore, target dietary supplement use in anti-doping education programmes by providing alternative strategies for performance enhancement or highlighting the safest ways they can be consumed. Similarly, as a large proportion of athletes use dietary supplements without doping, further research is needed to understand the factors that protect a dietary supplement user from doping. No funding was received for the review. A study protocol can be found here: https://osf.io/xvcaq.

Brain Endurance Training improves endurance and cognitive performance in road cyclists.

OBJECTIVES: To evaluate the effects of brain endurance training (BET) on endurance and cognitive performance in road cyclists. DESIGN: Two independent randomized controlled pretest-posttest training studies. METHODS: In both studies cyclists trained five times/week for six weeks and completed either cognitive response inhibition tasks (Post-BET group) or listened to neutral sounds (control group) after each training session. In Study-1, 26 cyclists performed a time to exhaustion (TTE) test at 80 % peak power output (PPO), followed by a 30-min Stroop task, and a TTE test at 65 % PPO. In Study-2, 24 cyclists performed a 5-min time trial, followed by a 30-min Stroop task, 60-min submaximal incremental test, and a 20-min . Heart rate, lactate, rating of perceived exertion (RPE), Stroop reaction time and accuracy were also measured. RESULTS: During Study 1, Post-BET improved TTE at 80 % (p = 0.032) and 65 % PPO (p = 0.011) significantly more than control with lower RPE (all p < 0.043). In Study 2, 5-min TT performance did not differ between groups. During the 60-min submaximal incremental test, RPE was lower in the Post-BET group compared to the control group (p = 0.034) and 20-min TT performance improved significantly more in the Post-BET group than in the control group (all p < 0.031). No group differences were found in physiological measures. In both studies, Stroop reaction times improved significantly more in the Post-BET group than in the control group (all p < 0.033). CONCLUSIONS: These findings suggest that Post-BET may be used to improve the performance of road cyclists.

Brain endurance training improves shot speed and accuracy in grassroots padel players.

OBJECTIVES: Evidence that mental fatigue impairs sport performance has created a demand for countermeasures. We examined the effects of brain endurance training, a form of fatigue-inoculation, on shot performance in grassroots padel players. DESIGN: A pre-, mid- and post-test design, with participants randomized to brain endurance training (n = 30) or control (n = 31) groups. METHODS: During testing, participants completed a Padel Stroke Performance Test, before and after a demanding 30-min cognitive task (Stroop). Training comprised 3 sessions/week for 6 weeks. In each training session, participants completed 10-min warm-up, 15-min technical drills, 15-min tactical drills, and 20-min simulated games. These physical activities were intermixed with short 4-min periods of Stroop (brain endurance training group) or rest (control group) totaling 20-min. Performance was measured by shot speed and accuracy of padel strokes. Mental fatigue indices were measured before and after the Stroop task using a visual analog scale rating, a psychomotor vigilance task, and a go/no-go task. RESULTS: During testing, the 30-min Stroop task elicited a state of mental fatigue, confirmed by higher subjective ratings, slower responses during the psychomotor vigilance task, and slower saccade latencies during the go/no go task. Compared to pre-testing, in mid- and post-testing, the brain endurance training group hit progressively faster and more accurate padel shots after the Stroop task compared to controls. CONCLUSIONS: Brain endurance training enhanced skill-based psychomotor performance when fatigued compared to standard padel training. Brain endurance training is a countermeasure that promotes mental fatigue durability.

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.

Prior brain endurance training improves endurance exercise performance.

Mental fatigue (MF) impairs endurance exercise performance. Brain endurance training (BET) describes the systematic repetition of mentally-fatiguing cognitive tasks designed to build resilience to MF and improve endurance performance. Evidence to date shows that mental training during physical training can benefit post-training exercise performance, however, this concurrent BET approach may not be practical for all settings. Therefore, the current study evaluated the effects of mental training before physical training (prior BET) on exercise performance. A randomised control trial design: pre-test, training (BET, control), post-test. During the pre-test and post-test sessions, participants performed a 5-min rhythmic handgrip task requiring the generation of as much force as possible, a 20-min 2-back working memory task, and another 5-min rhythmic handgrip task. Participants were randomly assigned to a BET (n = 12) or control group (n = 12). Both groups completed the same submaximal rhythmic handgrip training for five weeks (four sessions per week). The BET group also completed 20-min cognitive training (2-back working memory task, incongruent colour-word Stroop task) before each submaximal exercise training session. Endurance performance improved more (p < 0.05) following BET (24%) than physical training alone (12%). Compared to the control group, the BET group showed higher prefrontal oxygenation during the post-test exercise tasks (p < 0.05). Both groups were characterised by the same exertion, motivation, heart rate, and heart rate variability. Mental training before physical training improves endurance performance greater than physical training alone. The benefits of prior BET may be explained, at least in part, by improved prefrontal oxygenation.HighlightsThis study provides further evidence that brain endurance training (BET) improves performance over matched physical training.Prior BET (i.e. engaging in mentally demanding cognitive tasks before physical training) offers another option to enhance fatigue resilience, which expands the use of BET to more sports and potentially higher intensity training where concurrent BET will not be practical.The benefits of prior BET may be explained, at least in part, by improved prefrontal oxygenation.

Brain Endurance Training Improves Physical, Cognitive, and Multitasking Performance in Professional Football Players.

PURPOSE: Brain endurance training (BET)-the combination of physical training with mentally fatiguing tasks-could help athletes adapt and increase their performance during sporting competitions. Here we tested whether BET completed after standard physical training improved physical and mental performance more than physical training alone during a preseason football training camp. METHODS: The study employed a pretest/training/posttest design, with 22 professional football players randomly assigned to BET or a control group. Both groups completed 40 physical training sessions over 4 weeks. At the end of a day of physical training, the BET group completed cognitive training, whereas the control group listened to neutral sounds. Players completed the 30-15 Intermittent Fitness Test, repeated sprint ability random test, soccer-specific reactive agility test, and Stroop and psychomotor vigilance tests pretraining and posttraining. Mixed analysis of variance was used to analyze the data. RESULTS: In the posttest (but not pretest) assessments, the BET group consistently outperformed the control group. Specifically, the BET group was faster (P = .02-.04) than the control group during the 30-15 Intermittent Fitness Test, the directional phase of the repeated sprint ability random test, and the soccer-specific reactive agility test. The BET group also made fewer errors (P = .02) during the soccer-specific reactive agility test than the control group. Finally, the BET group responded faster (P = .02) on the Stroop test and made fewer (P = .03) lapses on the psychomotor vigilance test than the control group. CONCLUSION: The inclusion of BET during the preseason seems more effective than standard physical training alone in improving the physical, cognitive, and multitasking performance of professional football players.

A rowing-specific mindfulness intervention: Effects on mindfulness, flow, reinvestment, and performance.

Mindfulness can benefit athletes' mindset and performance. These benefits may be enhanced by sport-specific mindfulness interventions. Accordingly, our objectives were 2-fold: first, to develop a rowing-specific mindfulness intervention, and second, to investigate its effects on mindfulness, flow, reinvestment, and rowing performance. Rowers were randomly assigned to either a 6-week rowing-specific mindfulness intervention (n = 23), which included generic and rowing-specific practices, or a control group (n = 21). Rowers completed pre-test and post-test measures of performance, mindfulness, flow, and rowing-specific reinvestment. Lastly, rowers completed an evaluation form following the intervention. The results demonstrated that the intervention group increased flow, mindfulness, and improved performance, additionally conscious motor processing decreased from pre-test to post-test. However, the intervention did not preferentially change mindfulness or reinvestment compared to control. Participants provided favorable feedback and evaluated the intervention positively. Our 6-week rowing-specific mindfulness intervention promoted flow, encouraged mindfulness, and aided performance. Thus, we provide preliminary explorative evidence that a sport-specific mindfulness intervention can benefit athletes. We recommend that future research, with large sample sizes and improved home practice, should examine mediators and moderators of the mindfulness-performance relationship.

Cognitive tasks elicit mental fatigue and impair subsequent physical task endurance: Effects of task duration and type.

Although mentally fatiguing cognitive tasks can impair subsequent physical endurance, the importance of cognitive task duration and the role of response inhibition remain unclear. This study compared the effects of a serial incongruent Stroop color-classification task (i.e., with response inhibition) and N-back memory updating task (i.e., without response inhibition) on mental fatigue and subsequent rhythmic handgrip exercise. Participants (N = 90) were randomly assigned to one of three cognitive task groups (Stroop, 2-back, control) and completed four 10-min blocks of one cognitive task followed by a 5-min physical endurance task (self-paced rhythmic handgrip exercise). Heart rate, heart rate variability, electromyographic forearm activity, and force were recorded throughout along with self-reported measures of fatigue, exertion, and motivation. From the start, the Stroop and 2-back tasks elicited higher heart rate and lower heart rate variability as well as greater fatigue, effort, and interest/enjoyment than the control task. From the second block onwards, the Stroop and 2-back groups produced less force than the control group. There were no group differences in forearm muscle activity. In sum, mental fatigue was induced after performing a cognitive task for 10 mins, whereas muscular endurance was impaired after performing a cognitive task for 20 mins. That these effects were observed for both types of cognitive task indicates that response inhibition is not a necessary condition. The cognitive task duration required to induce mental fatigue and impair rhythmic handgrip endurance performance lay between the durations reported previously for isometric (a few minutes) and whole-body (half an hour) endurance exercise.

Moral values and moral identity moderate the indirect relationship between sport supplement use and doping use via sport supplement beliefs.

The Incremental Model of Doping Behaviour suggests doping grows out of the habitual use of performance-enhancing methods (e.g., sport supplements) and belief that they are necessary for performance. Importantly, in this model, doping is viewed as functional rather than moral choice. In two studies, we examined whether sport supplement use was indirectly related to doping use via sport supplement beliefs, and whether personal morality moderated this relationship. Competitive athletes (Study 1, N = 366; Study 2, N = 200) completed measures of supplement use, beliefs, and doping use. They also completed measures of moral values (Study 1) and moral identity (Study 2). In both studies, supplement use was indirectly related to doping use via beliefs. Moreover, this indirect relationship was moderated by moral values (Study 1) and moral identity (Study 2). That is, the relationship between supplement use and doping use via beliefs was negated when moral values and moral identity were high but not when they were low or moderate. Taken together, our findings suggest that sport supplement users, who believe they are necessary, are more likely to dope if they have low moral values and believe that being a moral person is unimportant to their self-image.

Effects of Cooperation and Competition on Performance, Emotion, and Effort: Goal and Means Interdependence.

Social interdependence theory proposes that task structure influences performance via social interaction. Using this framework, we examined sport performance. Fifty-six males performed a basketball task under four conditions: as an individual (individual, perform your best) and as a member of a team of two (cooperation, where teammates sought to better their individual performance; means independent competition, where two teams competed sequentially to outperform the other team; means interdependent competition, where two teams competed simultaneously to outperform the other team). Task performance (points) was better during means independent competition than other conditions. Anxiety and effort peaked during the competitions and enjoyment was greater during competition and cooperation than during the individual condition. Emotions, effort, and actions are discussed as explanations for the performance effects. Social interdependence theory provides a valuable framework to understand emotion, motivation, and performance. Team competition can be used to promote effort and enhance performance in sport.

The Rowing-Specific Reinvestment Scale.

This research project aimed to develop and validate a rowing-specific reinvestment scale. In Study 1, a 24-item questionnaire was developed and the content validity was assessed using experts (N = 7) and pilot-tested in rowers (N = 24). Next, rowers (N = 282) completed the questionnaire with the remaining items, and exploratory factor analysis (EFA) was conducted. This further reduced the number of items and revealed two factors, rowing specific conscious motor processing (RS-CMP) and movement self-consciousness (RS-MSC). In Study 2, rowers (N = 270) completed the scale that was evaluated using confirmatory factor analysis (CFA). Moreover, the construct validity of the scale was investigated by asking them to complete measures of movement-specific reinvestment, perceived performance, self-consciousness, and state anxiety. Actual performance was also determined based on their race finishing position. Study 1 EFA resulted in a 2-factor model with six items assessing RS-CMP and six items assessing RS-MSC. Study 2 supported the factor structure of scale; CFA indicated an acceptable model fit with good internal consistency. Content validity was also supported, with evidence of concurrent, convergent, discriminant, and predictive validity. In conclusion, these studies provided good initial evidence for the validity and reliability of the RSRS.

Ego orientation is related to doping likelihood via sport supplement use and sport supplement beliefs.

ABSTRACTA growing body of evidence suggests sport supplement use is positively related to doping likelihood, both directly and indirectly via beliefs that sport supplements are effective for improving performance. However, it is unclear what leads an athlete to use sport supplements and whether such factors play a role in the supplement-beliefs-doping relationship. To address this issue, we examined whether motivational goal orientations were related to doping likelihood directly and indirectly via sport supplement use and sport supplement beliefs. Competitive athletes (N = 362, 39% female, mean ± SD; age = 23.6 ± 10.3 years, hours per week training = 5.8 ± 2.1, years competing = 5.8 ± 5.4) from a range of sports (e.g. athletics, soccer, weightlifting) completed an online survey measuring task and ego goal orientation, sport supplement use, sport supplement beliefs, and doping likelihood. Results indicated that ego orientation, but not task orientation, was indirectly related to doping likelihood via sport supplement use and sport supplement beliefs. This suggests that athletes who are ego oriented are more likely to use supplements, believe supplements are effective, and dope. These data suggest that researchers should consider ego goal orientations when interpreting relationships between sport supplement use and doping likelihood.Highlights Ego orientation is related to doping likelihood via sport supplement use and beliefs.Task orientation is not related to doping likelihood via sport supplement use and beliefs.Ego-orientated athletes using sport supplements may be more likely to dope.Researchers should consider ego goal orientation when interpreting relationships between sport supplement use and doping likelihood.

The effects of vibrotactile masking on heartbeat detection: Evidence that somatosensory mechanoreceptors transduce heartbeat sensations.

The ability to detect heartbeat sensations is the most common basis for inferring individual differences in sensitivity to the interoceptive stimuli generated by the visceral activity. While the sensory sources of heartbeat sensations have yet to be identified, there is a growing consensus that visceral sensation, in general, is supported not only by the interoceptive system but also by the somatosensory system, and even by exteroception. The current experiment sought evidence on this issue by exploring the effects of masking the functions of somatosensory Pacinian and non-Pacinian mechanoreceptors on the ability to detect heartbeat sensations. Twelve verified heartbeat detectors completed a multi-session experiment in which they judged heartbeat-tone and light-tone simultaneity under two vibrotactile masking conditions involving the stimulation of the sternum: (a) using 250 Hz vibrotactile stimuli to mask the Pacinian channel, and (b) using 6 Hz vibrotactile stimuli to mask the non-Pacinian channel. A no-vibration control condition in which no masking stimuli were presented was also implemented. Presentation of both the 250 Hz and the 6 Hz masking stimuli impaired the ability to judge the simultaneity of heartbeats and tones but did not influence the ability to judge the simultaneity of stimuli presented to different exteroceptive modalities (lights and tones). Our findings reinforce the view that the somatosensory system is involved in cardioception and support the conclusion that both Pacinian and non-Pacinian somatosensory mechanoreceptors are implicated in heartbeat detection.

Concurrent brain endurance training improves endurance exercise performance.

OBJECTIVES: Mental fatigue impairs endurance exercise. Brain endurance training (BET) - engaging in cognitively fatiguing tasks during exercise - can develop resilience to mental fatigue and improve physical performance over physical training alone. The mechanism for this effect is unknown. This experiment examines if BET enhances performance over physical training and investigates potential underlying physiological mechanisms. DESIGN: A mixed design randomised control trial. METHODS: Pre- and post-testing: 36 participants completed dynamic rhythmic muscular endurance handgrip tasks requiring generation of as much force as possible once a second for 300s, performed under 3 counterbalanced conditions: following 600s of a 2-back memory/attention task (subsequent); while performing a 2-back task (concurrent); and on its own (solo). Cardiac activity, electromyographic forearm activity, pre-frontal cerebral haemodynamics (near infrared spectroscopy), and force were recorded. Training: Participants (randomised to a Control or BET group) completed 24 (6 weeks) submaximal hand contractions sessions. The BET group also completed concurrent cognitive tasks (2-back, Stroop). Measures of motivation, physical and mental exertion and mental fatigue were collected throughout. RESULTS: Endurance performance, across the 3 tasks, improved more following BET (32%) than Control (12%) (p<0.05). The better performance following BET occurred with a higher pre-frontal oxygenation during the post-training physical tasks over time relative to Control (p<0.05). CONCLUSIONS: Concurrent BET improved endurance performance over physical training alone. This was accompanied by a training-induced maintenance of pre-frontal oxygenation, suggestive of reduced mental effort during physical activity.