The perception of time is slowed in response to exercise, an effect not further compounded by competitors: behavioral implications for exercise and health.

INTRODUCTION: The theory of relativity postulates that time is relative to context and exercise seems such a situation. The purpose of this study was to examine whether situational factors such as perceived exertion and the introduction of an opponent influence competitors' perception of time. METHODS: Thirty-three recreationally active adults (F = 16; M = 17) performed three standardized 4-km cycling trials in a randomized order. Velotron 3D software was used to create a visual, virtual environment representing (1) a solo time trial (FAM and SO), (2) a time trial with a passive opponent avatar (PO), and (3) a time trial with an opponent avatar and participant instruction to actively finish the trial before the opponent (AO). Participants were asked to estimate a 30-s time period using a standardized protocol for reproducibility before exercise at 500 m, 1500 m, 2500 m, and post exercise. Rate of perceived exertion (RPE) was measured throughout the trials. RESULTS: Exercise trials revealed that time was perceived to run "slow" compared to chronological time during exercise compared to resting and post-exercise measurements (p < 0.001). There was no difference between exercise conditions (SO, PO, and AO) or time points (500 m, 1500 m, and 2500 m). RPE increased throughout the trials. CONCLUSION: The results of this study demonstrate for the first time that exercise both with and without the influence of opponents influences time perception. This finding has important implications for healthy exercise choices and also for optimal performance. Independent of RPE, time was perceived to move slower during exercise, underpinning inaccurate pacing and decision-making across physical activities.

Influence of intellectual disability on exercise regulation: exploring verbal, auditory and visual guidance to contribute to promote inclusive exercise environments.

Objective: The role of intellectual disability (ID) in exercise regulation has remained largely unexplored, yet recent studies have indicated cognitive-related impaired pacing skills in people with ID. In a well-controlled laboratory environment, this study aims to (1) establish the role of ID in pacing and explore the ability of people with and without ID to maintain a steady pace; (2) to investigate if verbal feedback and/or (3) the presence of a pacer can improve the ability of people with ID to maintain a preplanned submaximal velocity. Methods: Participants with (n=10) and without ID (n=10) were recruited and performed 7 min submaximal trials on a cycle ergometer (Velotron). Participants with ID also performed a cycling trial with a pacer (virtual avatar). Results: The non-parametric tests for repeated measures data (p≤0.05) showed that (1) people with ID deviated more from the targeted pace compared with people without ID, (2) the verbal feedback did not influence their ability to keep a steady pace and (3) they deviated less from the targeted pace when a visual pacer was introduced. Conclusion: The results revealed the difficulties of people with ID in planning and monitoring their exercise and the difficulties in appropriately responding to auditory and verbal feedback. Coaches and stakeholders who want to offer inclusive exercise pathways should consider that people with ID perform and pace themselves better when supported by intuitive, visual and personally meaningful stimuli such as other cyclists (avatars).

Carbohydrate mouth rinse improves performance of mentally fatigued cyclists despite null effects on psychological responses.

Mental fatigue reduces exercise performance through an impaired psychological response such as increased perceived exertion. Carbohydrate (CHO) mouth rinses improve exercise performance and perceived exertion likely due to an improved activation in cerebral reward areas, then we investigated if the CHO mouth rinse-improved exercise performance in mentally fatigued individuals was associated with ameliorated reward-related psychological responses. We hypothesised that CHO mouth rinse would be beneficial for mentally fatigued cyclists mainly in high-metabolic disturbance intensities. After familiarization and baseline sessions, well trained cyclists (n = 20) performed a maximal incremental test (MIT) after mental fatigue induction. They completed the MIT either without mouth rinse (MF) or rinsing their mouth with CHO (MF+CHO) or placebo (FM+PLA) solutions at every 25 % of the MIT. Psychological responses such as ratings of perceived exertion (RPE), affective valence, emotional arousal, and motivation were assessed throughout the MIT, while performance was assessed as peak power output and time of exercise. Mental fatigue reduced MIT performance (P < 0.05), but CHO mouth rinse was effective to counteract this deleterious mental fatigue effect (P < 0.05). However, we found null effects of CHO mouth rinses in psychological responses above the VT2 (P > 0.05) such as RPE, affective valence, emotional arousal, and motivation. Correlational analysis showed a significant, but moderate negative correlation between motivation and time of exercise above the VT2 when participants used CHO mouth rinse. In conclusion, the ergogenic CHO mouth rinse effects on MIT performance of mentally fatigued cyclists were irrespective of ameliorated psychological responses to exercise.

Coaching styles and sports motivation in athletes with and without Intellectual Impairments.

The cognitive limitations of athletes with Intellectual Impairments (II) may influence their sport behaviour and lead them to rely on coaches' support. However, it is still unclear how II may influence sports performance progression and motivation and how coaches perceive their athletes with II and coach them. Thus, this study aims to examine 1) coach's perceptions of motivation and performance progression in athletes with and without II, 2) coaching style (dis)similarities, and 3) the association between these factors. Coaches of athletes with (n = 122) and without II (n = 144) were recruited and completed three online questionnaires, analysed using a series of non-parametric analyses (p ≤ .05). Results showed that perceived performance progression and controlled motivation were higher of athletes with II while perceived autonomous motivation was higher of athletes without II. No coaching style differences were found between the two groups. Additionally, a need-supportive coaching style negatively predicted amotivation, and a need-thwarting coaching style predicted lower autonomous motivation in athletes with II only. Overall, it seems that the coaches perceived that their athletes with II demonstrate different motivations and react dissimilarly to their coaching styles compared to athletes without II. They may also adopt different standards of sporting success for them. Due to these differences, it is important to offer appropriate training and knowledge to coaches about disability sports and the adaptations needed to effectively coach athletes with II. In summary, this paper gives some insights about the coach-athlete relationship and highlights the necessity to further support the sports development of people with II.

Self-regulation of effort for a better health-related quality of life: a multidimensional activity pacing model for chronic pain and fatigue management.

PURPOSE: To propose a comprehensive multidimensional model of activity pacing that improves health-related quality of life and promotes sustained physical activity engagement among adults with chronic conditions. MATERIALS AND METHODS: A narrative review was conducted to examine the existing literature on activity pacing, health-related quality of life, pain and fatigue management, and physical activity promotion in chronic conditions. RESULTS: The literature revealed a lack of a cohesive approach towards a multidimensional model for using activity pacing to improve health-related quality of life. A comprehensive multidimensional model of activity pacing was proposed, emphasizing the importance of considering all aspects of pacing for sustained physical activity engagement and improved health-related quality of life. The model incorporates elements such as rest breaks, self-regulatory skills, environmental factors, and effective coping strategies for depression/anxiety. It takes into account physical, psychological, and environmental factors, all of which contribute significantly to the enhancement of health-related quality of life, physical function, and overall well-being, reflecting a holistic approach. CONCLUSIONS: The model offers guidance to researchers and clinicians in effectively educating patients on activity pacing acquisition and in developing effective interventions to enhance physical activity engagement and health outcomes among adults with chronic conditions. Additionally, it serves as a tool towards facilitating discussions on sustained physical activity and a healthy lifestyle for patients, which can eventually lead to improved quality of life.

Effectiveness of physical activity interventions on reducing perceived fatigue among adults with chronic conditions: a systematic review and meta-analysis of randomised controlled trials.

Fatigue is barrier of physical activity participation in adults with chronic conditions. However, physical activity alleviates fatigue symptoms. This systematic review and meta-analysis aimed to (1) synthesise evidence from randomised controlled trials (RCTs) exploring the effects of physical activity interventions on fatigue reduction and (2) evaluate their effectiveness. Medline/CINAHL/EMBASE/Web of Science and Scopus were searched up to June 24th, 2023. Two reviewers independently conducted study screening and selection (RCTs), extracted data and assessed risk of bias (RoB2). Outcome was the standardised mean difference (SMD) with 95% confidence intervals in fatigue between experimental and control groups. 38 articles met the inclusion criteria. Overall, physical activity interventions moderately reduced fatigue (SMD = 0.54, p < 0.0001). Interventions lasting 2-6 weeks demonstrated a larger effect on fatigue reduction (SMD = 0.86, p < 0.00001). Interventions with 18-24 sessions showed a large effect on fatigue reduction (SMD = 0.97, p < 0.00001). Aerobic cycling and combination training interventions had a large to moderate effect (SMD = 0.66, p = 0.0005; SMD = 0.60, p = 0.0010, respectively). No long-term effects were found during follow-up. Physical activity interventions moderately reduced fatigue among adults with chronic conditions. Duration, total sessions, and mode of physical activity were identified as key factors in intervention effectiveness. Further research is needed to explore the impact of physical activity interventions on fatigue.

Tactical positioning behaviours in short-track speed skating: A static and dynamic sequence analysis.

Tactical positioning is essential for success in short-track speed skating as the race format (direct, head-to-head competition over multiple laps) prioritises finishing position over finishing time. Despite this, current research into tactical positioning treats the race's laps as discrete, independent events. Accordingly, the aggregate metrics used to summarise each lap's tactical positioning behaviour do not allow us to explore the sequential nature of the data, e.g., Lap 2 occurs after Lap 1 and before Lap 3. Here, we capture the sequential relationships between laps to investigate tactical positioning behaviours in short-track speed skating. Using intermediate and final rankings from 500 m, 1,000 m, and 1,500 m elite short-track races, we analyse whole-race and sub-race race sequences of group and winner tactical positioning behaviours. This approach, combined with a large dataset of races collected over eight seasons of competition (n = 4,135), provides the most rigorous and comprehensive description of tactical positioning behaviours in short-track speed skating to date. Our results quantify the time-evolving complexity of tactical positioning, offer new thoughts on race strategy, and can help practitioners design more representative learning tasks to enhance skill transfer.

Unraveling the Role of (Meta-) Cognitive Functions in Pacing Behavior Development during Adolescence: Planning, Monitoring, and Adaptation.

PURPOSE: This study aimed to investigate whether (meta-) cognitive functions underpin the development of the self-regulated distribution of effort during exercise (i.e., pacing) throughout adolescence. METHODS: Participants included 18 adolescents (9 girls, 15.6 ± 2.5 yr old) and 26 adults (13 women, 26.8 ± 3.1 yr old), all recreationally active but unfamiliar with time trial cycling. The (meta-) cognitive functions involved in preexercise planning were quantified by calculating the difference between estimated and actual finish time during a 4-km cycling time trial. The capability to monitor and adapt one's effort distribution during exercise was measured during a 7-min submaximal trial, in which the participants were tasked with adhering to a set submaximal goal velocity either with (0-5 min) or without (5-7 min) additional feedback provided by the researcher. Analyses included between-group comparisons (ANOVA) and within-group comparisons (correlation) ( P < 0.05). RESULTS: Adolescents were less accurate in their estimation of the task duration. The adolescents' overestimation of task duration of the 4-km time trial was accompanied by pacing behavior characteristics resembling a longer trial (i.e., more even power output distribution, lower RPE, more pronounced end-spurt). Contrary to the adults, the adolescents deviated relatively more from the goal velocity during the 7-min submaximal trial, when no additional feedback was provided by the researcher. Within the adolescent group, estimation of task duration accuracy ( r = 0.48) and adherence to goal velocity ( r = 0.59) correlated with age. CONCLUSIONS: The (meta-) cognitive functions involved in the preexercise planning and the monitoring and adaptation of the distribution of effort during exercise underpin the development of pacing behavior during adolescence. Feedback from the (social) environment can be used to aid the monitoring and adaptation of effort expenditure in adolescents.

Sport Participation for People with Disabilities: Exploring the Potential of Reverse Integration and Inclusion through Wheelchair Basketball.

Reverse integration is defined as the inclusion of able-bodied people into disability sport. For decades, there have been movements towards integrating people with a disability in mainstream society. There has been a lack of research supporting the movement of able-bodied involvement in disability sport, known as reverse integration. In this study, the real-life experiences and motivations of 11 national wheelchair basketball players (four able-bodied and seven with a disability) were explored, identifying the potential of reverse integration and what influenced the players involvement. Thematic analysis was employed using a deductive approach. The social-relational model was used as a framework to help interpret the findings. The results highlighted that health and social benefits were key factors towards prolonged engagement in wheelchair basketball, and it was reported that reverse integration led to an increased mutual understanding of the impact of (dis)ability. All participants reported positive experiences and supported able-bodied involvement, suggesting that able-bodied players play a key role and help to grow the sport locally. However, involvement of able-bodied players was not supported at international level. This challenges the concept of inclusion at higher level and whether the sport could be more inclusive. These findings could provide direction to coaches and policymakers for developing further inclusive opportunities at all levels. Further research may explore coach education programs and learning experiences of becoming an inclusive coach to ensure coaches know how to create, stimulate and coach in inclusive sport environments.

The Role of Cognition and Social Factors in Competition: How Do People with Intellectual Disabilities Respond to Opponents?

Exploring pacing behaviour in people with intellectual disabilities (ID) in competition will help to better understand the impact of cognition and social environment in sports, providing support for the shaping of proper inclusive sports environments. The present experimental study aimed to (1) compare the pacing behaviour and performance between people with and without ID who are inexperienced in cycling and (2) investigate how these are influenced by an opponent. Participants with (n = 8) and without ID (n = 10) performed two randomised 4-km maximal cycling trials, alone and against an opponent. Non-parametric tests for repeated measures data (p ≤ 0.05) revealed that people with ID cycled slower, but with higher inter-individual variation (both conditions) and paced themselves differently compared to people without ID when competing against an opponent. In contrast to the previous literature in athletes without ID, the presence of a faster opponent resulted in a decrease in the performance in the participants with ID. The negative influence of the opponent highlights the potential difficulties people with ID experience to adequately use their opponents to enhance their self-regulatory processes and optimize their pacing and performance in maximal exercise trials. Coaches who want to offer inclusive sports environments for people with ID could take these findings into consideration.

The role of the social environment in inclusive sports participation-Identifying similarities and challenges in athletes with and without Intellectual Disabilities through coaches' eyes: A qualitative inquiry.

Despite the efforts of mainstreaming in sports, inclusive participation of people with Intellectual Disabilities (ID) in sports remains challenging. In sports settings, the social environment may influence the motivation of athletes and promote (or restrict) inclusive sports participation of athletes with ID. Thus, this study aims to explore the motivations of athletes and coaches and to investigate the role of the social environment in sports participation of athletes with and without ID. Coaches who coach athletes with ID (n = 11), athletes without ID (n = 13) and both groups (n = 2) were involved in semi-structured interviews. From the inductive thematic analysis three themes were identified for the sports motivations of athletes with ID (Sport-related Progression, Social Interaction, Positive Emotions), two for their coaches' motivations (Help others, Personal and Professional Development) and four for coaching practices toward athletes with ID (Psychological and Life skills development, Building Meaningful Relationships, Behaviour adaptations and Participation-focused). Moreover, 'Teammates and Opponents' and 'Family' were classified as social agents that influence the sport participation of athletes with ID. Coaches of athletes without ID reported additional themes about their athletes' motivations (Health-related Reasons), their coaching motivations (Career aspirations) and their coaching practices towards athletes without ID (Performance-focused). The motivations of athletes and the practices of coaches could promote sports participation of athletes with ID, but more work is needed to address athletes' sports motivations and overcome the able-ist attitudes and the social oppression that may make their inclusion in sports more challenging. These sports participation barriers and facilitators could provide direction to stakeholders for developing inclusive sports pathways to people with ID.

Tactical positioning in short-track speed skating: The utility of race-specific athlete-opponent interactions.

In short-track speed skating, tactical positioning is essential for success as the race format (head-to-head) prioritises finishing position over finishing time. At present, our understanding of this phenomenon is based on measuring the similarity between athletes' intermediate and final rankings. However, as this approach groups athlete performances across races, each lap's estimate of tactical importance ignores the athlete-opponent interactions specific to each race. Here, we examine the utility of race-specific athlete-opponent interactions for investigating tactical positioning. Using intermediate and final rankings of elite 1,000 m short-track speed skating competitors collected from 2010/11-2017/18 (n = 6,196, races = 1,549), we compared the current method to a novel approach that accounted for race-specific athlete-opponent interactions. This approach first applied the current method to each race independently before using these values to form (1) discrete, empirical distributions of each lap's tactical importance and (2) race-specific tactical positioning sequences. Our results showed that accounting for race-specific athlete-opponent interactions provided a higher measurement granularity (i.e. level of detail) for investigating tactical positioning in short-track speed skating, which better captured the complexity of the phenomenon. We observed 61 different tactical positioning behaviours and 1,269 unique tactical positioning sequences compared to the current approach's nine-point estimates of tactical positioning importance. For this reason, we recommend that researchers and practitioners account for race-specific athlete-opponent interactions in the future as it offers a deeper understanding of tactical positioning that will enhance both strategic and tactical decisions.HighlightsWe compare the current approach for investigating tactical positioning to a novel approach that accounts for race-specific athlete-opponent interactions.We show that accounting for race-specific athlete-opponent interactions provides a higher measurement granularity (i.e. level of detail) for investigating tactical positioning in short-track speed skating.We demonstrate that this increased measurement granularity can facilitate a deeper understanding of tactical positioning by (1) producing theoretically-more-correct point estimates of tactical positioning importance, (2) enabling more rigorous statistical analyses into the effect of athlete-environment interactions on tactical positioning behaviour, and (3) allowing sequential analyses that capture the progressive relationships between laps.We recommend that researchers and practitioners account for race-specific athlete-opponent interactions in future investigations, as the findings will enhance analyst, coach, and athlete preparation for the strategic and tactical decision-making process essential for success in short-track.

Pacing Behavior Development in Adolescent Swimmers: A Large-Scale Longitudinal Data Analysis.

PURPOSE: This study aimed to use a large-scale longitudinal design to investigate the development of the distribution of effort (e.g., pacing) in adolescent swimmers, specifically disentangling the effects of age and experience and differentiating between performance levels in adulthood. METHODS: Season best times and 50-m split times of 100- and 200-m freestyle swimmers from five continents were gathered between 2000 and 2021. Included swimmers competed in a minimum of three seasons between 12 and 24 yr old (5.3 ± 1.9 seasons) and were categorized by performance level in adulthood (elite, sub-elite, high-competitive; 100-m: n = 3498 (47% female); 200-m: n = 2230 (56% female)). Multilevel models in which repeated measures (level 1) were nested within individual swimmers (level 2) were estimated to test the effects of age, race experience, and adult performance level on the percentage of total race time spent in each 50-m section ( P < 0.05). RESULTS: In the 100-m, male swimmers develop a relatively faster first 50-m when becoming older. This behavior also distinguishes elite from high-competitive swimmers. No such effects were found for female swimmers. Conversely, more experienced male and female swimmers exhibit a slower initial 50-m. With age and race experience, swimmers develop a more even velocity distribution in the 200-m. Adolescent swimmers reaching the elite level adopt a more even behavior compared with high-competitive. This differentiation occurs at a younger age in female (>13 yr) compared with male (>16 yr) swimmers. CONCLUSIONS: Pacing behavior development throughout adolescence is driven by age-related factors besides race experience. Swimmers attaining a higher performance level during adulthood exhibit a pacing behavior that better fits the task demands during adolescence. Monitoring and individually optimizing the pacing behavior of young swimmers is an important step toward elite performance.

Exploring correlates of physical activity behaviour in UK children and their inter-relationships using a multidisciplinary approach: A concept mapping study.

It is still unknown which correlates of physical activity behaviour (PAB) may be effective and how they may influence PAB in UK children. The objective of the current study was to generate a conceptual analysis of the correlates of PAB in UK children (5-12 years) using the input of researchers in the field of physical activity (PA experts; PAE) and other fields (non-PA experts; non-PAE). A concept mapping approach was used to identify potential (new) correlates of PAB in children, assess their importance based on rating of potential modifiability and effect, and generate a concept map depicting the associations between them. In the first (brainstorming) stage (n = 32 experts) yielded 93 correlates, including 14 new correlates not identified in previous reviews. In the second (rating and sorting) stage (n = 26 experts), 32 correlates were rated as important and a four-cluster concept map was generated including themes related to Society/community, Home/social setting, Personal/social setting and Psychological/emotional correlates. Two additional concept maps were generated for PAE and non-PAE. From expert opinion, we identified new correlates of PAB that warrant further research and we highlight the need to consider the interaction between intrapersonal and external correlates when designing interventions to promote PA in UK children.

The Role of the Social Environment in Pacing and Sports Performance: A Narrative Review from a Self-Regulatory Perspective.

As proposed by Triplett in 1898 and evidenced by a recent series of lab and field studies, racing against other competitors consistently results in increased performance compared to when racing alone. To explain this phenomenon, we will explore the process of self-regulation, a process relevant to pacing, which is linked to athletes' emotions and facilitates their sports performance optimization. We will apply the cyclical model of Self-regulation of Learning to pacing and sports performance settings and explore the role of the social environment (in particular, opponents but also coaches) in each phase of the self-regulatory model. It seems that the social environment could be considered as a significant self-regulatory and sports performance facilitator. More specifically, athletes can focus on their social environment (opponents) when they have to set goals and select appropriate strategies to achieve them (forethought phase), monitor and manage their actions and their emotions (performance phase), and make self-judgements and choose self-reactions (self-reflection). Moreover, the social environment (coaches) can observe, step in, and facilitate these intricate processes. These findings could guide athletes and their coaches towards more effective pacing acquisition and development, and better sports performance, which could be of particular relevance for youth athletes or athletes with disabilities impacting on their self-regulatory skills.

Pacing Behaviour Development and Acquisition: A Systematic Review.

BACKGROUND: The goal-directed decision-making process of effort distribution (i.e. pacing) allows individuals to efficiently use energy resources as well as to manage the impact of fatigue on performance during exercise. Given the shared characteristics between pacing behaviour and other skilled behaviour, it was hypothesized that pacing behaviour would adhere to the same processes associated with skill acquisition and development. METHODS: PubMed, Web of Science and PsycINFO databases between January 1995 and January 2022 were searched for articles relating to the pacing behaviour of individuals (1) younger than 18 years of age, or (2) repeatedly performing the same exercise task, or (3) with different levels of experience. RESULTS: The search resulted in 64 articles reporting on the effect of age (n = 33), repeated task exposure (n = 29) or differing levels of experience (n = 13) on pacing behaviour. Empirical evidence identifies the development of pacing behaviour starts during childhood (~ 10 years old) and continues throughout adolescence. This development is characterized by an increasingly better fit to the task demands, encompassing the task characteristics (e.g. duration) and environment factors (e.g. opponents). Gaining task experience leads to an increased capability to attain a predetermined pace and results in pacing behaviour that better fits task demands. CONCLUSIONS: Similar to skilled behaviour, physical maturation and cognitive development likely drive the development of pacing behaviour. Pacing behaviour follows established processes of skill acquisition, as repeated task execution improves the match between stimuli (e.g. task demands and afferent signals) and actions (i.e. continuing, increasing or decreasing the exerted effort) with the resulting exercise task performance. Furthermore, with increased task experience attentional capacity is freed for secondary tasks (e.g. incorporating opponents) and the goal selection is changed from achieving task completion to optimizing task performance. As the development and acquisition of pacing resemble that of other skills, established concepts in the literature (e.g. intervention-induced variability and augmented feedback) could enrich pacing research and be the basis for practical applications in physical education, healthcare, and sports.

The reward for placebos: mechanisms underpinning placebo-induced effects on motor performance.

Different from the most popular thinking, the placebo effect is not a purely psychological phenomenon. A body of knowledge from multidisciplinary fields has shown that the expectation of a potential benefit when receiving a treatment induces a cascade of neurochemical-electrophysiological alterations in brain reward areas, including motor-related ones. Alterations in the dopamine, opioid, and glutamate metabolism are the neural representation converting reward-derived declarative forms into an attractive and wanted behavior, thereby changing the activation in reward subcortical and cortical structures involved in motor planning, motor execution, and emotional-cognitive attributes of decision-making. We propose that the expectation of receiving a treatment that is beneficial to motor performance triggers a cascade of activations in brain reward areas that travels from motor planning and motor command areas, passing through corticospinal pathways until driving the skeletal muscles, therefore facilitating the motor performance. Although alternative explanations cannot be totally ruled out, this mechanistic route is robust in explaining the results of placebo-induced effects on motor performance and could lead to novel insights and applications in the exercise sciences. Factors such as sex differences in reward-related mechanisms and aversion-induced nocebo effects should also be addressed.

Pacing behaviour of middle-long distance running & race-walking athletes at the IAAF U18 and U20 World Championship finals.

ABSTRACTThe current study analysed the pacing behaviour of athletes competing in the middle-long track event finals of the IAAF Under 18 and Under 20 World Championships between 2015 and 2018. Official finishing times, 1000-m split times and positioning data of 116 female and 153 male athletes, competing in the middle-long distance running (3000 m, 5000 m and 10,000 m) and race walking (5000 m and 10,000 m) events, were gathered. Repeated measures analysis of variance, with 1000-m speed as within-subjects factor and final ranking (medallist, Top 8 or Top 12, rest of the field) as between-subjects factor, was performed to compare the pacing behaviour between athletes. Positioning of the athletes was analysed by Kendall tau-b (Tb) correlation between the intermediate position and final position. Overall, medallists increased their speed throughout a race, with the exception of the 5000 m running event, in which a parabolic pacing behaviour was exhibited. The 1000-m segment in which a significant (P > 0.05) difference in speed was exhibited between differently ranked athletes coincided with a strong (Tb > 0.7) correlation between intermediate and final positioning. These combined results point towards a separation between the athletes during the race, as the Top 8 or Top 12 and the rest of the field are unable to match the speed of the medallists. The distance, discipline, sex, age category and behaviour of competitors all influence the pacing behaviour of young track athletes during international level competition, emphasising the importance and complexity of developing adequate pacing behaviour in track athletes. HighlightsThe distribution of effort over an exercise task (i.e. pacing) is an important factor in endurance exercise competition. The pacing behaviour of athletes is determined by many aspects, such as the biomechanical characteristics of the task, the exercise environment and the age of the athleteSport specific competition data from youth athlete sports events can provide insight into the pacing behaviour of developing athletes. These insights could assist in the optimalisation of the development of pacing behaviour of young athletes in the future.The current study analysed the 1000-m split times and positioning data of athletes competing in the running (3000 m, 5000 m and 10,000) and racewalking (5000 m and 10,000m) finals of the U18 and U20 IAAF world-championship.The difference in final ranking impacted the pacing behaviour of the athletes, with the medallists increasing their speed throughout the race and the other athletes separating from the medallists either early (rest of field) or later in the race (Top 8 or Top 12 athletes).

Carbohydrate Mouth Rinse Mitigates Mental Fatigue Effects on Maximal Incremental Test Performance, but Not in Cortical Alterations.

Detrimental mental fatigue effects on exercise performance have been documented in constant workload and time trial exercises, but effects on a maximal incremental test (MIT) remain poorly investigated. Mental fatigue-reduced exercise performance is related to an increased effort sensation, likely due to a reduced prefrontal cortex (PFC) activation and inhibited spontaneous behavior. Interestingly, only a few studies verified if centrally active compounds may mitigate such effects. For example, carbohydrate (CHO) mouth rinse potentiates exercise performance and reduces effort sensation, likely through its effects on PFC activation. However, it is unknown if this centrally mediated effect of CHO mouth rinse may mitigate mental fatigue-reduced exercise performance. After a proof-of-principle study, showing a mental fatigue-reduced MIT performance, we observed that CHO mouth rinse mitigated MIT performance reductions in mentally fatigued cyclists, regardless of PFC alterations. When compared to placebo, mentally fatigued cyclists improved MIT performance by 2.24-2.33% when rinsing their mouth with CHO during MIT. However, PFC and motor cortex activation during MIT in both CHO and placebo mouth rinses were greater than in mental fatigue. Results showed that CHO mouth rinse mitigated the mental fatigue-reduced MIT performance, but challenged the role of CHO mouth rinse on PFC and motor cortex activation.

Pacing Behavior Development of Youth Short-Track Speed Skaters: A Longitudinal Study.

PURPOSE: This study aimed to analyze the development of pacing behavior of athletes during adolescence using a longitudinal design. METHODS: Lap times of male short-track speed skaters (140 skaters, 573 race performances) over two or more 1500-m races during Junior World Championships between 2010 and 2018 were analyzed. Races were divided into four sections (laps 1-3, 4-7, 8-11, and 12-14). Using MLwiN (P < 0.05), multilevel prediction models in which repeated measures (level 1) were nested within individual athletes (level 2) were used to analyze the effect of age (15-20 yr), race type (fast, slow), and stage of competition (final, nonfinal) on absolute section times and relative section times (percentage of total time spent in a section). RESULTS: Between the ages of 15 and 20 yr, total race time decreased (-6.99 s) and skaters reached lower absolute section time in laps 8-11 (-2.33 s) and 12-14 (-3.28 s). The relative section times of laps 1-3 (1.42%) and 4-7 (0.66%) increased and of laps 8-11 (-0.53%) and 12-14 (-1.54%) decreased with age. Fast races were more evenly paced compared with slow races, with slow races having a predominantly slow first half and fast finish. Athletes in finals were faster (2.29 s), specifically in laps 4-7 (0.85 s) and laps 8-11 (0.84 s). CONCLUSION: Throughout adolescence, short-track speed skaters develop more conservative pacing behavior, reserving energy during the start of the race in order to achieve a higher velocity in the final section of the race and a decrease in total race time. Coaches should take into consideration that the pacing behavior of young athletes develops during adolescence, prepare athletes for the differences in velocity distribution between race types, and inform them on how to best distribute their efforts over the different stages of competition.