Application of decision-making theory to the regulation of muscular work rate during self-paced competitive endurance activity

Performance and Psychophysiological Effects of Light-Guided Pacing During a 5000-m Run

PURPOSE

In world-class middle- and long-distance running races, a Wavelight signal has recently been used as a pacing guide for setting records. The aim of the present study was to compare performance and psychophysiological effects between light-guided, drafting, and nonassisted pacing conditions in distance runners.

METHODS

Fifteen male middle- and long-distance runners of national and regional standard ran three 5000-m time trials in a counterbalanced order with the following pacing distribution: the first 4000 m and last 1000 m were covered at submaximal and maximal intensities, respectively. The 3 trials (conditions) were (1) self-paced, (2) guided by a light signal, and (3) guided by a cyclist in front (drafting condition). Pace, heart rate, rating of perceived exertion, and affective valence were recorded every 500 m.

RESULTS

No statistically significant differences were found between pacing-light and self-paced conditions. Running time was shorter in the drafting versus self-paced condition in the final 500-m section (P = .031; d = 0.76). No differences were found between drafting and light conditions. Similarly, whereas 9 out of 10 significant differences in terms of lower heart rate, or rating of perceived exertion, or higher affective valence responses were found in the drafting versus self-paced condition (P = .004-.041; d = 0.63-1.39), only 4 were found across the tests in the drafting versus light condition (P = .005-.016; d = 0.66-0.84).

CONCLUSION

Light-guided pacing did not influence performance or psychophysiological responses in distance runners during a 5000-m test, but drafting produced a large effect.

Pacing Behavior Development: The Role of Task Experience and the Presence of Competitors

INTRODUCTION

Self-regulation of effort during exercise (i.e., pacing) is a determinant of exercise performance, which develops during childhood and adolescence. Yet the various aspects of pacing under development, such as the capability to use task experience and retain the task goal in the presence of other competitors, have remained relatively unexplored.

METHODS

Nine adolescents (14.9 ± 2.1 yr old) and 14 adults (24.2 ± 3.2 yr old) completed four 4-km cycling trials in a well-controlled laboratory setting. After one familiarization visit, trials were performed in random order: alone, with the goal to finish the trial as fast as possible (AloneTime), with a competitor and the same goal (CompTime), or with a competitor and the goal to finish first (CompFirst). Within each age-group, repeated-measures ANOVA ( P < 0.05) examined the differences in the estimated task duration, pacing behavior (distribution of mean power output per 500 m), and performance (finish time) between visits (4) or conditions (3).

RESULTS

In contrast to adults ( P < 0.05, ηp2 > 0.20), adolescents did not exhibit a change in estimation of task duration, pacing behavior, or performance over repeated visits ( P > 0.05, ηp2 < 0.10). Adolescents altered their pacing behavior in the presence of a competitor independent of the task goal (CompTime and CompFirst), whereas adults only demonstrated this alteration when instructed to finish first (CompFirst).

CONCLUSIONS

Adolescents are still developing the capability 1) to use experience from previous tasks to adjust their pacing behavior and 2) to inhibit the intuitive action of engaging with the competitor to retain the more abstract task goal of finishing the trial as fast as possible. These findings establish novel experimental evidence for the underpinnings of pacing behavior development.

The influence of aerobic capacity on the loads and intensities of mixed martial arts sparring bouts

The influence of aerobic variables on mixed martial arts (MMA) performance is currently unknown. This study aimed to compare the laboratory-measured aerobic variables of MMA participants to the external load and intensity of MMA sparring bouts to determine the effect of aerobic capacity on performance. Ten participants (age = 24 ± 2.8 years; mass = 74.3 ± 8.2 kg; stature = 176.8 ± 7.9 cm) completed the following: a treadmill-graded exercise test to measure V̇O2max, VT1 and VT2; 3 × 5 mins sparring bout equipped with a Catapult Optimeye S5 accelerometer recording Playerload (PLdACC) and Playerload per minute (PLdACC∙min-1), with a sessional rating of perceived exertion (sRPE) recorded as internal intensity. Median V̇O2max (53.3 ml∙kg∙min-1) was used to split the cohort into the top 50% and bottom 50%. Pearson's r correlations (BF10 ≥ 3) were calculated between GXT and sparring variables. V̇O2max (53.1 ± 5.9 ml∙kg∙min-1) was found to have very large (r ≥ .70) linear relationships with PLdACC (161.4 ± 27.2 AU) and PLdACC∙min-1 (10.7 ± 1.8AU). The top 50% group maintained moderate sRPE (4-6AU) and greater PLdACC∙min-1 throughout the bout, with the bottom 50% group's sRPE moving from moderate to high (>7AU) indicating V̇O2max <53 ml∙kg∙min-1 is related to increased internal intensity. These data support the aerobic nature of MMA and may provide aerobic capacity targets for athletes and coaches to aim for during competition preparation.

Pacing strategies in marathons: A systematic review

Background

The pacing strategy embodies the tactical behavior of athletes in distributing their energy across different segments of a race; therefore, a quantitative analysis of pacing strategies in marathon races could deepen the understanding of both pacing behavior and physical capacity in marathon athletics.

Objective

The objective of this systematic review was to synthesize and characterize pacing strategies in marathon road races by exploring the categories of pacing strategies and the factors that influence these strategies during marathon events.

Methods

Preferred Reporting Items for Systematic Reviews guidelines were followed for systematic searches, appraisals, and syntheses of literature on this topic. Electronic databases such as Science Direct, SPORTDiscuss, PubMed, and Web of Science were searched up to July 2024. Records were eligible if they included pace performance measurements during competition, without experimental intervention that may influence their pace, in healthy, adult athletes at any level.

Results

A total of 39 studies were included in the review. Twenty-nine were observational studies, and 10 were experimental (randomized controlled trials). The assessment of article quality revealed an overall median NOS score of 8 (range 5-9). The included studies examined the pacing profiles of master athletes and finishers in half-marathon (n = 7, plus numbers compared to full marathon), full-marathon (n = 21), and ultramarathon (n = 11) road races. Considering that some studies refer to multiple pacing strategies, in general, 5 studies (∼13 %) reported even pacing, 3 (∼8 %) reported parabolic pacing, 7 (∼18 %) reported negative pacing, and 30 (∼77 %) reported positive pacing during marathon competitions. Gender, age, performance, pack, and physiological and psychological factors influence pacing strategies.

Conclusion

This study synthesized pacing performance in marathons and highlighted the significance of examining pacing strategies in these events, offering valuable insights for coaches and athletes. Several key findings were highlighted: (1) pacing profiles and pacing ranges were identified as the primary indicators of pacing strategies; (2) the pacing strategy was found to be dynamic, with the most substantial effects attributed to gender and distance; and (3) three distinct types of pacing strategies for marathons were classified: positive, negative, and even pacing. These findings advance the understanding of marathon pacing strategies by shedding light on the factors that influence athletes' pacing decisions and behaviors. Additionally, these findings offer practical benefits, aiding athletes in making well-informed tactical choices and developing effective pace plans to enhance marathon performance. However, due to the complex nature of marathon racing, further research is required to explore additional factors that might impact pacing strategies. A better grasp of optimal pacing strategies will foster progress in this area and serve as a basis for future research and advancements.

"Falling Behind," "Letting Go," and Being "Outsprinted" as Distinct Features of Pacing in Distance Running

INTRODUCTION

In distance running, pacing is characterized by changes in speed, leading to runners dropping off the leader's pace until a few remain to contest victory with a final sprint. Pacing behavior has been well studied over the last 30 years, but much remains unknown. It might be related to finishing position, finishing time, and dependent on critical speed (CS), a surrogate of physiologic capacity. We hypothesized a relationship between CS and the distance at which runners "fell behind" and "let go" from the leader or were "outsprinted" as contributors to performance.

METHODS

100-m split times were obtained for athletes in the men's 10,000-m at the 2008 Olympics (N = 35). Split times were individually compared with the winner at the point of "falling behind" (successive split times progressively slower than the winner), "letting go" (large increase in time for distance compared with winner), or "outsprinted" (falling behind despite active acceleration) despite being with the leader with 400 m remaining.

RESULTS

Race times ranged between 26:55 and 29:23 (world record = 26:17). There were 3 groups who fell behind at ∼1000 (n = 11), ∼6000 (n = 16), and ∼9000 m (n = 2); let go at ∼4000 (n = 10), ∼7000 (n = 14), and ∼9500 m (n = 5); or were outkicked (n = 6). There was a moderate correlation between CS and finishing position (r = .82), individual mean pace (r = .79), "fell behind" distance (r = .77), and "let go" distance (r = .79). D' balance was correlated with performance in the last 400 m (r = .87).

CONCLUSIONS

Athletes displayed distinct patterns of falling behind and letting go. CS serves as a moderate predictor of performance and final placing. Final placing during the sprint is related to preservation of D' balance.

Differences in pacing behaviour between global championship medal performances and world records in men's and women's middle- and long-distance running track events

The differences in pacing demands between track distance-running championship and meet (e.g., World Record [WR]) races have not been specified yet in the current literature. Therefore, the aim of this study was to determine pacing behaviour differences between WRs and global championship (i.e., World Championships and Olympic Games) medal performances (GCMs) in middle- and long-distance running events. Percentages of mean race section speeds were compared through analysis of variance between men's and women's 169 WRs and 189 GCMs over 800 m, 1500 m, 3000 m steeplechase, 5000 m and 10,000 m. U-shaped and negative pacing approaches are observed during men's and women's 1500 m WRs and GCMs, respectively. The first and third 400 m of men's and women's 1500 m GCMs were relatively slower and faster, respectively (p ≤ 0.05, 1.31 ≤ d ≤ 1.69). Even profiles are followed during women's 3000 m steeplechase WRs and GCMs, whereas positive approaches were adopted in men's GCMs. Finally, whereas 5000 m and 10,000 m GCMs were finished with a fast endspurt, WRs had a U-shaped profile in men, with differences between the initial and last race stages (p ≤ 0.01, 1.20 ≤ d ≤ 3.66), and an even profile in women. Coaches should consider the different pacing demands existing among meet and global championship races to specifically implement training characteristics targeting either goal type.

Analysing experienced and inexperienced cyclists' attentional focus and self-regulatory strategies during varying intensities of fixed perceived effort cycling: A mixed method study

Using a think aloud approach during fixed perceived effort exercise is a unique method to explore the decision-making processes that guide the self-regulation of perceived effort during endurance-based activity. In a two-part study, authors investigated the attentional focus and self-regulatory strategies associated with: Part A - perceived effort corresponding to (RPEGET) and above gas exchange threshold (RPE+15%GET); Part B - between experienced and inexperienced cyclists during fixed perceived effort cycling tasks. Eighteen (15 male, 3 female) healthy, active individuals completed three visits (visit 1 - ramped incremental test and familiarisation, visit 2 and 3-30-min fixed perceived effort cycling). During which, power output, heart rate, lactate, think aloud, and perceptual markers were taken. Random-intercepts linear mixed-effects models assessed the condition, time, and condition × time interactions on all dependent variables. Power output, heart rate, lactate and instances of internal sensory monitoring (t195=2.57,p=.011,β=0.95[0.23,1.68]) and self-regulation (t195=4.14,p=.001,β=1.69[0.89,2.49]) were significantly higher in the RPE+15%GET versus RPEGET trial. No significant differences between inexperienced and experienced cyclists for internal sensory monitoring (t196=-1.78,p=.095,β=-1.73[-3.64,0.18]) or self-regulatory thoughts (t196=-0.39,p=.699,β=-1.06[-6.32,4.21]) were noted but there were significant condition × time interactions for internal monitoring (t196=2.02,p=.045,β=0.44[0.01,0.87]) and self-regulation (t196=3.45,p=.001,β=0.85[0.37,1.33]). Seemingly, experienced athletes associatively attended to internal psychophysiological state and subsequently self-regulate their psychophysiological state at earlier stages of exercise than inexperienced athletes. This is the first study to exhibit the differences in attentional focus and self-regulatory strategies that are activated based on perceived effort intensity and experience level in cyclists.

Evolution of 1500-m Olympic Running Performance

PURPOSE

This study determined the evolution of performance and pacing for each winner of the men's Olympic 1500-m running track final from 1924 to 2020.

METHODS

Data were obtained from publicly available sources. When official splits were unavailable, times from sources such as YouTube were included and interpolated from video records. Final times, lap splits, and position in the peloton were included. The data are presented relative to 0 to 400 m, 400 to 800 m, 800 to 1200 m, and 1200 to 1500 m. Critical speed and D' were calculated using athletes' season's best times.

RESULTS

Performance improved ∼25 seconds from 1924 to 2020, with most improvement (∼19 s) occurring in the first 10 finals. However, only 2 performances were world records, and only one runner won the event twice. Pacing evolved from a fast start-slow middle-fast finish pattern (reverse J-shaped) to a slower start with steady acceleration in the second half (J-shaped). The coefficient of variation for lap speeds ranged from 1.4% to 15.3%, consistent with a highly tactical pacing pattern. With few exceptions, the eventual winners were near the front throughout, although rarely in the leading position. There is evidence of a general increase in both critical speed and D' that parallels performance.

CONCLUSIONS

An evolution in the pacing pattern occurred across several "eras" in the history of Olympic 1500-m racing, consistent with better trained athletes and improved technology. There has been a consistent tactical approach of following opponents until the latter stages, and athletes should develop tactical flexibility, related to their critical speed and D', in planning prerace strategy.

Serum brain-derived neurotrophic factor (BDNF) and self-paced time-trial performance in older untrained men

PURPOSE

This study examined the effect of 12 weeks of concurrent aerobic and resistance training on brain derived neurotrophic factor (BDNF) levels, neuromuscular performance and cerebral oxygenation on self-paced cycling exercise in previously untrained older men.

METHODS

Eight untrained healthy males aged 53-64 years performed a familiarisation and a pre-training self-paced cycling time trial before 12 weeks of exercise training which combined aerobic and resistance exercise. The self-paced cycling time trial comprised a 30 s maximal effort sprint for every 4.5 min of lower intensity pace for a total of 25 min. Upon completion of 12 weeks of training, a comparison of the pre-training trial analysed for serum BDNF, neuromuscular performance, and cerebral oxygenation was undertaken.

RESULTS

Serum BDNF decreased significantly from 10.02 ± 4.63 to 6.96 ± 3.56 ng/ml after 12 weeks of training. There was also attenuated physiological strain for a comparable self-paced cycling performance. Despite positive physiological responses during the time trial pacing strategy was not altered compared with pre training.

CONCLUSION

BDNF decreases following 12 weeks of concurrent training and might reflect neuroplasticity for this type of training stimulus. Exercise training in previously sedentary older men can result in a multitude of physical benefits, which may also confer a neuroprotective effect. However, specific training is required to improve pacing strategies in previously untrained older males.

CLINICAL TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry number ACTRN12622001477718.

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.

Test-retest reliability of a 30-min fixed perceived effort cycling exercise

PURPOSE

Using exercise protocols at a fixed rating of perceived effort (RPE) is a useful method for exploring the psychophysical influences on exercise performance. However, studies that have employed this protocol have arbitrarily selected RPE values without considering how these values correspond to exercise intensity thresholds and domains. Therefore, aligning RPE intensities with established physiological thresholds seems more appropriate, although the reliability of this method has not been assessed.

METHODS

Eight recreationally active cyclists completed two identical ramped incremental trials on a cycle ergometer to identify gas exchange threshold (GET). A linear regression model plotted RPE responses during this test alongside gas parameters to establish an RPE corresponding to GET (RPE_GET) and 15% above GET (RPE_+15%GET). Participants then completed three trials at each intensity, in which performance, physiological, and psychological measures were averaged into 5-min time zone (TZ) intervals and 30-min 'overall' averages. Data were assessed for reliability using intraclass correlation coefficients (ICC) and accompanying standard error measurements (SEM), 95% confidence intervals, and coefficient of variations (CoV).

RESULTS

All performance and gas parameters showed excellent levels of test-retest reliability (ICCs =  > .900) across both intensities. Performance, gas-related measures, and heart rate averaged over the entire 30-min exercise demonstrated good intra-individual reliability (CoV =  < 5%).

CONCLUSION

Recreationally active cyclists can reliably replicate fixed perceived effort exercise across multiple visits when RPE is aligned to physiological thresholds. Some evidence suggests that exercise at RPE_+15%GET is more reliable than RPE_GET.

Ischemic preconditioning and exercise performance: are the psychophysiological responses underestimated?

The findings of the ischemic preconditioning (IPC) on exercise performance are mixed regarding types of exercise, protocols and participants' training status. Additionally, studies comparing IPC with sham (i.e., low-pressure cuff) and/or control (i.e., no cuff) interventions are contentious. While studies comparing IPC versus a control group generally show an IPC significant effect on performance, sham interventions show the same performance improvement. Thus, the controversy over IPC ergogenic effect may be due to limited discussion on the psychophysiological mechanisms underlying cuff maneuvers. Psychophysiology is the study of the interrelationships between mind, body and behavior, and mental processes are the result of the architecture of the nervous system and voluntary exercise is a behavior controlled by the central command modulated by sensory inputs. Therefore, this narrative review aims to associate potential IPC-induced positive effects on performance with sensorimotor pathways (e.g., sham influencing bidirectional body-brain integration), hemodynamic and metabolic changes (i.e., blood flow occlusion reperfusion cycles). Overall, IPC and sham-induced mechanisms on exercise performance may be due to a bidirectional body-brain integration of muscle sensory feedback to the central command resulting in delayed time to exhaustion, alterations on perceptions and behavior. Additionally, hemodynamic responses and higher muscle oxygen extraction may justify the benefits of IPC on muscle contractile function.

Do players competing in the UEFA Champions League maintain running performance until the end of the match? Positional analysis between halves and 5-minute intervals

BACKGROUND

This investigation aimed to analyze differences in running performances amongst playing positions between the first and second halves of soccer matches and at 5-minute intervals during matches.

METHODS

Data were collected from 179 soccer players during 20 UEFA Champions League (UCL) 2020/2021 group stage matches. Data were examined using the InStat Fitness semi-automatic video system. Eight variables were selected to quantify players' running performance (RP). Players were categorized based on positional groups: central defenders (CD), fullbacks (FB), central midfielders (CM), wide midfielders (WM), and forwards (FW). Univariate differences in RP were analyzed using ANOVA and the t-test for dependent samples and multivariate differences were identified using canonical discriminant analysis.

RESULTS

The main findings were that all positions achieved significantly higher average speeds and walking distances in the first half of the match than in the second half. Furthermore, analysis of positions showed that CM covered more distance than CD in all 5-minute intervals. In addition, WM performed more high-intensity running than CD in all 5-minute intervals and FW performed more high-intensity running than all other playing positions.

CONCLUSIONS

The findings from the present study should help coaches design training exercises that are specific to parts of a match. Moreover, the findings can help provide better understanding of match demands and individualization of training. Analysis of 5-minute intervals may also help coaches understand the stages of a match where player substitutions will be most effective.

Can plyometric training change the pacing behaviour during 10-km running?

The effects of plyometric training (PT) on middle- and long-distance running performances are well established. However, its influence on pacing behaviour is still unclear. The aim of this study was to evaluate the effects of PT on pacing behaviour. In addition, verify whether the adaptations induced by PT would change ratings of perceived exertion (RPE) and/or affective feelings during the race. Twenty-eight male runners were assigned to two groups: control (C) and PT. PT held two weekly PT sessions for eight weeks. Drop jump (DJ) performance, 10-km running performance, pacing behaviour, RPE and affective feelings, VO_2peak, ventilatory thresholds (VT1 and VT2), peak treadmill speed (PTS), and running economy (RE) were measured. For group comparisons, a mixed model analysis for repeated measures, effect size (ES) and 90% confidence interval (90% CI) were calculated for all dependent variables. Significant differences pre-to-post was observed for PT group in DP (7.2%; p ≤ 0.01; ES = 0.56 (0.28-0.85)) and RE (4.5%; p ≤ 0.05; ES = -0.52 ((-0.73 to -0.31)) without changes in pacing behaviour. While PT was effective for improving DJ and RE, there is no evidence that pacing behaviour, RPE or affective feelings are directly affected by these adaptations during a 10-km time trial run.

Competition Between Desired Competitive Result, Tolerable Homeostatic Disturbance, and Psychophysiological Interpretation Determines Pacing Strategy

Scientific interest in pacing goes back >100 years. Contemporary interest, both as a feature of athletic competition and as a window into understanding fatigue, goes back >30 years. Pacing represents the pattern of energy use designed to produce a competitive result while managing fatigue of different origins. Pacing has been studied both against the clock and during head-to-head competition. Several models have been used to explain pacing, including the teleoanticipation model, the central governor model, the anticipatory-feedback-rating of perceived exertion model, the concept of a learned template, the affordance concept, the integrative governor theory, and as an explanation for "falling behind." Early studies, mostly using time-trial exercise, focused on the need to manage homeostatic disturbance. More recent studies, based on head-to-head competition, have focused on an improved understanding of how psychophysiology, beyond the gestalt concept of rating of perceived exertion, can be understood as a mediator of pacing and as an explanation for falling behind. More recent approaches to pacing have focused on the elements of decision making during sport and have expanded the role of psychophysiological responses including sensory-discriminatory, affective-motivational, and cognitive-evaluative dimensions. These approaches have expanded the understanding of variations in pacing, particularly during head-to-head competition.

The influence of race tactics for performance in the heats of an international sprint cross-country skiing competition

The purpose of this study was to examine the influence of race tactics for performance in the heats of an international sprint cross-country (XC) skiing competition in the classical style. Thirty elite male XC skiers (age: 24±3 years, sprint International Ski Federation [FIS] points: 61±27) performed a sprint time-trial (STT) followed by one to three 'knock-out' heats on a 1.7 km racecourse. An integrated GNSS/IMU system was used to determine position, sub-technique distribution and kinematics. Positioning was analysed using the television broadcast of the race. STT rank correlated positively with the final rank [(rs (28) = .72, P = .001)]. The top-two finishers in each heat were on average ~3.8% slower in the heats compared to the STT (237.1±3.9 vs. 228.3±4.0 seconds, P = .001). On average, the skiers performed ~10 overtakings per 100 meters from the start to the last uphill segment but only ~3 overtakings per 100 meters in the last two segments in each heat. 93.8% of the top-two finishing skiers positioned themselves at top 2 before approaching the final uphill, in which the top-two finishers and the skiers ranked 3-4 were generally faster than those ranked 5-6 in the heats (both, P = .01). Here, top-four skiers employed 5.3% longer cycle lengths and 3.4% higher cycle rates in the diagonal sub-technique than skiers ranked 5-6 (all, P = .01). The present study demonstrates the importance of race tactics for performance in the heats of sprint XC skiing, in which the main performance-determining factors in the present racecourse were a front position when approaching the final uphill segment combined with the ability to ski fast in that segment. In general, this illustrates how accurate racecourse analyses may help skiers to optimize their race-individual race-strategies in the heats of sprint XC skiing competitions.

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.

Current Perspectives of Cross-Country Mountain Biking: Physiological and Mechanical Aspects, Evolution of Bikes, Accidents and Injuries

Mountain biking (MTB) is a cycling modality performed on a variety of unpaved terrain. Although the cross-country Olympic race is the most popular cross-country (XC) format, other XC events have gained increased attention. XC-MTB has repeatedly modified its rules and race format. Moreover, bikes have been modified throughout the years in order to improve riding performance. Therefore, the aim of this review was to present the most relevant studies and discuss the main results on the XC-MTB. Limited evidence on the topic suggests that the XC-MTB events present a variation in exercise intensity, demanding cardiovascular fitness and high power output. Nonetheless, these responses and demands seem to change according to each event. The characteristics of the cyclists differ according to the performance level, suggesting that these parameters may be important to achieve superior performance in XC-MTB. Moreover, factors such as pacing and ability to perform technical sections of the circuit might influence general performance. Bicycles equipped with front and rear suspension (i.e., full suspension) and 29″ wheels have been shown to be effective on the XC circuit. Lastly, strategies such as protective equipment, bike fit, resistance training and accident prevention measures can reduce the severity and the number of injuries.

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 to 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.

Effects of air pollution exposure on inflammatory and endurance performance in recreationally trained cyclists adapted to traffic-related air pollution

The aim of the present study was to analyze the effects of traffic-related air pollution (TRAP) on markers of inflammatory, neuroplasticity, and endurance performance-related parameters in recreationally trained cyclists who were adapted to TRAP during a 50-km cycling time-trial (50-km cycling TT). Ten male cyclists performed a 50-km cycling TT inside an environmental chamber located in downtown Sao Paulo (Brazil), under TRAP or filtered air conditions. Blood samples were obtained before and after the 50-km cycling TT to measure markers of inflammatory [interleukin-6 (IL-6), C-Reactive protein (CRP), interleukin-10 (IL-10), intercellular adhesion molecule-1 (ICAM-1)], and neuroplasticity [brain-derived neurotrophic factor (BDNF)]. Rating of perceived exertion (RPE), heart rate (HR), and power output (PO) were measured throughout the 50-km cycling TT. There were no significant differences between experimental conditions for responses of IL-6, CRP and IL-10 (P > 0.05). When compared with exercise-induced changes in filtered air condition, TRAP provoked greater exercise-induced increase in BDNF levels (TRAP = 3.3 ± 2.4 fold change; Filtered = 1.3 ± 0.5 fold change; P = 0.04) and lower exercise-induced increase in ICAM-1 (Filtered = 1.1 ± 0.1 fold change; TRAP = 1.0 ± 0.1 fold change; P = 0.01). The endurance performance-related parameters (RPE, HR, PO, and time to complete the 50-km cycling TT) were not different between TRAP and filtered air conditions (P > 0.05). These findings suggest that the potential negative impacts of exposure to pollution on inflammatory, neuroplasticity, and performance-related parameters do not occur in recreationally trained cyclists who are adapted to TRAP.

Selected vs. Non-Selected Under-20 National Futsal Players: Differences between Physical Performance and Training Intensity Experienced in Training Camps

The aim of this study was two-fold: (i) analyze the variations in the physical fitness of selected and non-selected under-20 male national futsal players; and (ii) analyze the variations in training intensity monitored during training camps. Thirty-three Taiwan under-20 national futsal players were monitored for training intensity during 18 training camps. They were divided into two groups: selected (n = 14) and non-selected (n = 17) players. The physical assessments included the following measures: body mass, distance covered at Yo-Yo intermittent recovery test Level 1, final velocity at 30-15 Intermittent Fitness Test (30-15 IFT), standing long jump, maximum heart rate (HR), and 1-min sit-up. The training intensity was monitored using the rate of perceived exertion (RPE), HR at different intensity zones, and locomotor demands measured at different speed thresholds. The results revealed that the selected players were significantly faster in the 15-m sprint with ball (p = 0.001) and 30-m sprint (p = 0.001). Additionally, the selected players presented significantly greater HRaverage and time spent above 90% maximum HR during the three-to-six-day training camps (p < 0.05) compared to the non-selected players. Interestingly, the NS demonstrated a greater number of sprints during the training camps (p = 0.001), while the selected players presented greater distance/minute and average speed (p = 0.001). A regression analysis showed that the distance/minute and average speed was a significant predictor of maximum HR in the selected players. As conclusions, the physical fitness outcomes are different between the selected and non-selected national futsal players. The selected players spent more time in high intensity HR demands in training sessions.

Pacing Profiles of Middle-Distance Running World Records in Men and Women

The aims of the current study were to compare the pacing patterns of all-time 800 m, 1500 m and mile running world records (WRs) and to determine whether differences exist between sexes, and if 800 m and 1500 m WRs were broken during championship or meet races. Overall and lap times for men and women’s 800 m, 1500 m, and mile WRs from World Athletics were collected when available and subsequently compared. A fast initial 200 m segment and a decrease in speed throughout was found during 800 m WRs. Accordingly, the first 200 m and 400 m were faster than the last 200 m and 400 m, respectively (p < 0.001, 0.77 ≤ ES ≤ 1.86). The first 400 m and 409 m for 1500 m and mile WRs, respectively, were faster than the second lap (p < 0.001, 0.74 ≤ ES ≤ 1.46). The third 400 m lap was slower than the last 300 m lap and 400 m lap for 1500 m and mile WRs, respectively (p < 0.001, 0.48 ≤ ES ≤ 1.09). No relevant sex-based differences in pacing strategy were found in any event. However, the first 409 m lap was faster than the last 400 m lap for men but not for women during mile WRs. Women achieved a greater % of WRs than men during championships (80% vs. 45.83% in the 800 m, and 63.63% vs. 31.58% in the 1500 m, respectively). In conclusion, positive, reverse J-shaped and U-shaped pacing profiles were used to break 800 m, men’s mile and 1500 m, and women’s mile WRs, respectively. WRs are more prone to be broken during championships by women than men.

In-Season Body Composition Effects in Professional Women Soccer Players

This study aimed to analyze anthropometric and body composition effects in professional soccer women players across the early and mid-competitive 2019/20 season. Seventeen players (age, height, body mass, and body mass index of 22.7 ± 6.3 years, 167.5 ± 5.6 cm, 60.7 ± 6.6 kg and 21.6 ± 0.2 kg/m2) from a Portuguese BPI League team participated in this study. The participants completed ≥80% of 57 training sessions and 13 matches. They were assessed at three points (before the start of the season (A1), after two months (A2), and after four months (A3)) using the following variables: body fat mass (BFM), soft lean mass (SLM), fat-free mass (FFM), intracellular water (ICW), extracellular water (ECW), total body water (TBW), and phase angle (PhA, 50 Khz), through InBody S10. Nutritional intake was determined through a questionnaire. Repeated measures ANCOVA and effect sizes (ES) were used with p < 0.05. The main results occurred between A1 and A2 for BFM (-21.7%, ES = 1.58), SLM (3.7%, ES = 1.24), FFM (4%, ES = 1.34), ICW (4.2%, ES = 1.41), TBW (3.7%, ES = 1.04). Furthermore, there were significant results between A1 and A3 for FFM (4.8%, ES = 1.51), ICW (5%, ES = 1.68), and PhA (10.4%, ES = 6.64). The results showed that the water parameters improved over time, which led to healthy hydration statuses. The training load structure provided sufficient stimulus for appropriate physical fitness development, without causing negative disturbances in the water compartments.

Pacing profiles and tactical behaviors of elite runners

The pacing behaviors used by elite athletes differ among individual sports, necessitating the study of sport-specific pacing profiles. Additionally, pacing behaviors adopted by elite runners differ depending on race distance. An "all-out" strategy, characterized by initial rapid acceleration and reduction in speed in the later stages, is observed during 100 m and 200 m events; 400 m runners also display positive pacing patterns, which is characterized by a reduction in speed throughout the race. Similarly, 800 m runners typically adopt a positive pacing strategy during paced "meet" races. However, during championship races, depending on the tactical approaches used by dominant athletes, pacing can be either positive or negative (characterized by an increase in speed throughout). A U-shaped pacing strategy (characterized by a faster start and end than during the middle part of the race) is evident during world record performances at meet races in 1500 m, 5000 m, and 10,000 m events. Although a parabolic J-shaped pacing profile (in which the start is faster than the middle part of the race but is slower than the endspurt) can be observed during championship 1500 m races, a negative pacing strategy with microvariations of pace is adopted by 5000 m and 10,000 m runners in championship races. Major cross country and marathon championship races are characterized by a positive pacing strategy; whereas a U-shaped pacing strategy, which is the result of a fast endspurt, is adopted by 3000 m steeplechasers and half marathoners. In contrast, recent world record marathon performances have been characterized by even pacing, which emphasizes the differences between championship and meet races at distances longer than 800 m. Studies reviewed suggest further recommendations for athletes. Throughout the whole race, 800 m runners should avoid running wide on the bends. In turn, during major championship events, 1500 m, 5000 m, and 10,000 m runners should try to run close to the inside of the track as much as possible during the decisive stages of the race when the speed is high. Staying within the leading positions during the last lap is recommended to optimize finishing position during 1500 m and 5000 m major championship races. Athletes with more modest aims than winning a medal at major championships are advised to adopt a realistic pace during the initial stages of long-distance races and stay within a pack of runners. Coaches of elite athletes should take into account the observed difference in pacing profiles adopted in meet races vs. those used in championship races: fast times achieved during races with the help of one or more pacemakers are not necessarily replicated in winner-takes-all championship races, where pace varies substantially. Although existing studies examining pacing characteristics in elite runners through an observational approach provide highly ecologically valid performance data, they provide little information regarding the underpinning mechanisms that explain the behaviors shown. Therefore, further research is needed in order to make a meaningful impact on the discipline. Researchers should design and conduct interventions that enable athletes to carefully choose strategies that are not influenced by poor decisions made by other competitors, allowing these athletes to develop more optimal and successful behaviors.

Meso-pacing in Olympic and World Championship sprints and hurdles: Medallists save their best for the final

The aim of this novel study was to analyse performance changes across qualifying heats, semi-finals and finals in world-class sprinters and hurdlers. Finalists' finishing positions, times and rankings at the Olympic Games and IAAF World Championships (2012-2019) were obtained. 78% of gold, 67% of silver and 38% of bronze medallists won their qualifying heat and semi-final, and in most events final placings were associated with finishing positions in the qualifying heats (P ≤ 0.006), but not with finishing times. Medallists ran faster in each successive round (P < 0.001), whereas those finishing between 4^th-6^th did not improve on their semi-final times. Most athletes finishing last and second-last ran the final slower than both their semi-final and qualifying heats. The short hurdles events, with fixed barrier heights and distances, differed from the other races as the medallists were faster than most rivals in the qualifying rounds (P < 0.05), and their race times did not improve from the semi-final to the final. Coaches should note that the world's best athletes were able to conserve energy for the final within a meso-pacing strategy throughout the championships, which was more important in the short hurdles, and requires preparation within their training regimens.

Distinct pacing profiles result in similar perceptual responses and neuromuscular fatigue development: Why different "roads" finish at the same line?

ABSTRACTThe current study analysed the effect of distinct pacing profiles (i.e. U, J, and inverted J) in the perceptual responses and neuromuscular fatigue (NMF) development following a 4-km cycling time trial (TT). Twenty-one cyclists with similar training status were allocated into three different groups based on their pacing profile spontaneously adopted during TT. Rating of perceived exertion (RPE), oxygen uptake (⩒O₂) and heart rate (HR) were continuously recorded. NMF was assessed by using isometric maximal voluntary contractions (IMVC), while the central [i.e. voluntary activation (VA)] and peripheral fatigue of knee extensors [i.e. peak torque of potentiated twitches (TwPt)] were evaluated using electrically evoked contractions performed pre and 2 min after the TT. TT performance was not different amongst pacing profiles (U = 377 ± 20 s; J = 392 ± 23 s; J-i = 381 ± 20 s) (all P > 0.05). RPE, ⩒O₂ and HR increased similarly throughout the TT regardless the pacing strategy (all P > 0.05). Similarly, IMVC (U = -9.9 ± 8.8; J = -9.6 ± 4.5%; J-i = -13.8 ± 11.3%), VA (U = -2.3 ± 1.7%; J = -5.4 ± 2.2%; J-i = -6.4 ± 4.5%) and TwPt (U = -32.5 ± 12.0%; J = -29.5 ± 8.0%; J-i = -33.6 ± 13.6%) were similar amongst pacing profiles (all P > 0.05). Therefore, endurance athletes with similar training status showed the same perceived responses and NMF development regardless the pacing profile spontaneously adopted. It was suggested that these responses occurred in order to preserve a similar rate of change in systemic responses (i.e. RPE, ⩒O₂ and HR) and NMF development, ultimately resulting in same TT performance.Highlights Different pacing profiles resulted in the same performance in a 4-km cycling time trial.The similar performance might be due to achievement of the same sensory tolerance limit.There was no difference for perceptual, metabolic and neuromuscular fatigue responses.

Performance demands in the endurance rider

Endurance is one of the fastest growing equestrian disciplines worldwide. Races are long distance competitions (40-160 km), organised into loops, over variable terrain usually within one day. Horse and rider combinations in endurance races have to complete the course in good condition whilst also aiming to win. Horse welfare is paramount within the sport and horses are required to ‘pass’ a veterinary check prior to racing, after each loop of the course and at the end of the race. Despite the health, fitness and welfare of both athletes within the horse-rider dyad being essential to achieve success, few equivalent measures assessing the wellbeing of the endurance rider are implemented. This review considers evidence from ultra-endurance sports and rider performance in other equestrian disciplines, to consider physiological and psychological strategies the endurance rider could use to enhance their competition performance. Successful endurance riding requires an effective partnership to be established between horse and rider. Within this partnership, adequate rider health and fitness are key to optimal decision-making to manage the horse effectively during training and competition, but just as importantly riders should manage themselves as an athlete. Targeted management for superior rider performance can underpin more effective decision-making promoting ethical equitation practices and optimising competition performance. Therefore, the responsible and competitive endurance rider needs to consider how they prepare themselves adequately for participation in the sport. This should include engaging in appropriate physiological training for fitness and musculoskeletal strength and conditioning. Alongside planning nutritional strategies to support rider performance in training and within the pre-, peri- and post-competition periods to promote superior physical and cognitive performance, and prevent injury. By applying an evidence informed approach to self-management, the endurance athlete will support the horse and rider partnership to achieve to their optimal capacity, whilst maximising both parties physical and psychological wellbeing.

Pacing Profiles of Olympic and IAAF World Championship Long-Distance Runners

ABSTRACT

Filipas, L, La Torre, A, and Hanley, B. Pacing profiles of Olympic and International Association of Athletics Federations World Championship long-distance runners. J Strength Cond Res 35(4): 1134-1140, 2021-The aim of this study was to analyze the pacing profiles of Olympic and International Association of Athletics Federations (IAAF) World Championship long-distance finalists, including the relationship with their recent best times. The times for each 1,000-m split were obtained for 394 men and women in 5,000- and 10,000-m finals at 5 championships. Athletes' best times from the previous 32 months were also obtained. Similar pacing profiles were used by athletes grouped by finishing position in 5,000-m races. Women adopted a more even pacing behavior, highlighting a possible sex-based difference over this distance. Pacing behavior over 10,000 m was more similar between men and women compared with over 5,000 m. The main difference between men and women was that in the men's 10,000 m, as in the men's 5,000 m, more athletes were able to follow the leading group until the final stages. There were large or very large correlations between athletes' best times from the previous 32 months and their result; the fastest finishers also ran closer to their previous 32 months' best times. Despite differences in pacing behavior between events, long-distance runners should nonetheless stay close to the front from the beginning to win a medal.

Quantitative EEG in sports: performance level estimation of professional female soccer players

Purpose

Measuring the peak performance of athletes remains a challenge in movement science and sports psychology. Non-invasive quantitative electroencephalography (QEEG) recordings can be used to analyze various factors in sports psychology.

Method

In this context, sports-related psychological factors were used to estimate the performance of Thai professional female soccer players before a competition. The QEEG recordings of thirty-two players were recorded three times: twice before a competition (once a week) and a week after a competition. Four factors of sports psychology were estimated and observed: anxiety, perceptual response to an acute bout of brain activity, assertiveness, and brain central fatigue. A brain topographic map (absolute power) and brain connectivity (coherence and amplitude asymmetry) data were used to analyze sports-related psychological factors. These factors were measurable based on the brain activity of the athletes and could be used to evaluate their performance during competitions by using QEEG values.

Results

Sports-related psychological performance was estimated by Pearson's correlation coefficients, which revealed that a quick perceptual response to an acute bout of brain activity could predict an athlete's performance during competition (r = .584, p = .000). Additionally, Spearman's correlation coefficients were used to estimate athletes performance. The results revealed a strong relationship ( r s =.634, p = .000), which was derived from the summation of anxiety and perceptual response to an acute bout of brain activity.

Conclusion

Consequently, the results of the present study can provide information to help staff coaches to choose the best performing players, representing an alternative method for accurately selecting key players in the competitive sports community.

Effects of different goal orientations and virtual opponents performance level on pacing strategy and performance in cycling time trials

We investigated the effects of different performance goals (best time vs. beat the opponent) on pacing behaviour during a 10-km cycling race and explored the influence of different performance level of opponents on ratings of perceived exertion (RPE), affective feelings and self-efficacy. Thirteen cyclists performed two time-trials (TT) and two races against a faster (FAST +6%) or a slower (SLOW -3%) virtual opponent. Power output (PO), RPE, affective feelings and self-efficacy were recorded at each kilometre point. Race average and race phases [starting (P1 = first kilometre); first half (P2 = 2nd-5th kilometre); second half (P3 = 6th-9th kilometre) and final sprint (FS = last kilometre)] were analysed. There was no difference in performance, assessed by race time between conditions (p = .84). PO during TT was lower in P3 compared to FS (p = .03; ES 0.6; 90%CI 0.4-0.7). In SLOW and FAST, PO was higher in P1 compared to other phases (p < .05). PO in FS was higher in TT compared to FAST (p = .01; ES -0.97; 90%IC -1.4 to -0.5). RPE increased and affective feelings decreased during all conditions. Self-efficacy was stable through TT and SLOW, but decreased during FAST with higher values in P1 compared to P2 (p = .01; ES -1.1; 90%IC -1.6 to -0.6), P3 (p < .001; ES -2.2; 90%IC -2.8 to -1.6) and FS (p < .001; ES -2.6; 90%IC -3.3 to -1.8). Pacing behaviour, specifically starting and final sprint, was affected by virtual opponents independent of performance level, demonstrating the importance of goal orientation. HighlightsAdjustments in exercise intensity result from a complex decision-making process involving physiological, psychological, environmental and tactical information.Goal pursuit is an important determinant of pacing behaviour since athletes must balance their efforts with expectations of success.A competitive environment may be included to motivate participants to maintain their effort and at the same time to improve their self-confidence.The presence of a final sprint seems to be related to the goal orientation and perceived outcomes of success or failure.

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 (T_b) 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 (T_b> 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).

Fatigue development and perceived response during self-paced endurance exercise: state-of-the-art review

Performance in self-paced endurance exercises results from continuous fatigue symptom management. While it is suggested that perceived responses and neuromuscular fatigue development may determine variations in exercise intensity, it is uncertain how these fatigue components interact throughout the task. To address the fatigue development in self-paced endurance exercises, the following topics were addressed in the present review: (1) fatigue development during constant-load vs. self-paced endurance exercises; (2) central and peripheral fatigue and perceived exertion interconnections throughout the self-paced endurance exercises; and (3) future directions and recommendations. Based on the available literature, it is suggested (1) the work rate variations during a self-paced endurance exercise result in transitions between exercise intensity domains, directly impacting the end-exercise central and peripheral fatigue level when compared to constant-load exercise mode; (2) central and peripheral fatigue, as well as perceived exertion response contribute to exercise intensity regulation at the different stages of the trial. It seems that while neuromuscular fatigue development might be relevant at beginning of the trial, the perceived exertion might interfere in the remaining parts to achieve maximal values only at the finish line; (3) future studies should focus on the mechanisms underpinning fatigue components interactions throughout the task and its influence on exercise intensity variations.

Fatigue development and perceived response during self-paced endurance exercise: state-of-the-art review

Performance in self-paced endurance exercises results from continuous fatigue symptom management. While it is suggested that perceived responses and neuromuscular fatigue development may determine variations in exercise intensity, it is uncertain how these fatigue components interact throughout the task. To address the fatigue development in self-paced endurance exercises, the following topics were addressed in the present review: (1) fatigue development during constant-load vs. self-paced endurance exercises; (2) central and peripheral fatigue and perceived exertion interconnections throughout the self-paced endurance exercises; and (3) future directions and recommendations. Based on the available literature, it is suggested (1) the work rate variations during a self-paced endurance exercise result in transitions between exercise intensity domains, directly impacting the end-exercise central and peripheral fatigue level when compared to constant-load exercise mode; (2) central and peripheral fatigue, as well as perceived exertion response contribute to exercise intensity regulation at the different stages of the trial. It seems that while neuromuscular fatigue development might be relevant at beginning of the trial, the perceived exertion might interfere in the remaining parts to achieve maximal values only at the finish line; (3) future studies should focus on the mechanisms underpinning fatigue components interactions throughout the task and its influence on exercise intensity variations.

More Pace Variation and Pack Formation in Successful World-Class 10,000-m Runners Than in Less Successful Competitors

PURPOSE

To determine different relationships between, and predictive ability of, performance variables at intermediate distances with finishing time in elite male 10,000-m runners.

METHODS

Official electronic finishing and 100-m split times of the men's 10,000-m finals at the 2008 and 2016 Olympic Games and IAAF World Championships in 2013 and 2017 were obtained (125 athlete performances in total). Correlations were calculated between finishing times and positions and performance variables related to speed, position, time to the leader, and time to the runner in front at 2000, 4000, 6000, 8000, and 9900 m. Stepwise linear-regression analysis was conducted between finishing times and positions and these variables across the race. One-way analysis of variance was performed to identify differences between intermediate distances.

RESULTS

The SD and kurtosis of mean time, skewness of mean time, and position and time difference to the leader were either correlated with or significantly contributed to predictions of finishing time and position at at least one of the analyzed distances (.81 ≥ r ≥ .30 and .001 ≤ P ≤ .03, respectively). These variables also displayed variation across the race (.001 ≤ P ≤ .05).

CONCLUSIONS

The ability to undertake a high degree of pace variability, mostly characterized by acceleration in the final stages, is strongly associated with achievement of high finishing positions in championship 10,000-m racing. Furthermore, the adoption and maintenance of positions close to the front of the race from the early stages are important to achieve a high finishing position.

Winning by hiding behind others: An analysis of speed skating data

In some athletic races, such as cycling and types of speed skating races, athletes have to complete a relatively long distance at a high speed in the presence of direct opponents. To win such a race, athletes are motivated to hide behind others to suppress energy consumption before a final moment of the race. This situation seems to produce a social dilemma: players want to hide behind others, whereas if a group of players attempts to do so, they may all lose to other players that overtake them. To support that speed skaters are involved in such a social dilemma, we analyzed video footage data for 14 mass start skating races to find that skaters that hid behind others to avoid air resistance for a long time before the final lap tended to win. Furthermore, the finish rank of the skaters in mass start races was independent of the record of the same skaters in time-trial races measured in the absence of direct opponents. The results suggest that how to strategically cope with a skater's dilemma may be a key determinant for winning long-distance and high-speed races with direct opponents.

Does the distribution of the weekly training load account for the match results of elite professional soccer players?

PURPOSE

The aim of the study was to compare training load (TL) of the days preceding a win, draw or defeat in a sample of elite professional soccer players across the in-season 2015/16.

METHODS

Twenty elite soccer players participated in this study. Total distance covered, high-speed running distance (HSRD), average speed, session rate of perceived exertion (s-RPE) and Hooper index scores (HI) were collected. Data from 24 weeks with one match were analysed through the match-day (MD-5, 4, 3, 2, 1) and MD+1.

RESULTS

The main finding emerges in MD-1, where a longer training duration preceding draws (95.1 ± 1.5 min) > defeats (91.5 ± 1.6 min) > wins (84.7 ± 0.5 min) was found, while total distance and average speed were higher in wins (3628.6 ± 57.2 m) > draws (3391.3 ± 153.3 m) > defeats (3236.1 ± 113.7 m) and draws (130.7 ± 17.6 m/min) > wins (86.0 ± 6.9 m/min) > defeats (54.8 ± 7.1 m/min), respectively. HSRD was higher in draws (42.8 ± 0.6 m) > wins (36.1 ± 1.7 m) > defeats (35.8 ± 1.7 m). In MD+1, there were differences in HI between wins vs draws (p<0.01).

CONCLUSIONS

The results are drawn from one team that participated in UEFA Champions League. It was observed that different TL applied in training sessions can influence match result. Our findings can be considered in future soccer planning and periodization to win matches. This study emphasizes the use of HI especially in the day following the match.

The Ability of Runners to Identify Spatial and Temporal Variables of Speed During Endurance Running

This study aimed to evaluate spatial and temporal perception in endurance runners as a mechanism of pacing control in comparison with other athletes (soccer players). A group of 38 endurance runners and 32 soccer players participated in this study. Runners displayed lower time differences and lower error than soccer players. Taking the athletic levels of endurance runners into consideration, significant differences (p = .011, Cohen's d = 1.042) were found in the time differences (higher level group = 33.43 ± 29.43 vs. lower level group = 123.53 ±102.61). Significant correlations were found between time differences and performance in a Cooper test (r = -.546) and with the best time in a half marathon (r = .597). Temporal and spatial perception can be considered as a cognitive skill of endurance runners.

Different race pacing strategies among runners covering the 2017 Berlin Marathon under 3 hours and 30 minutes

The purposes of this study were 1) to analyse the different pacing behaviours based on athlete's performance and 2) to determine whether significant differences in each race split and the runner's performance implied different race profiles. A total of 2295 runners, which took part in Berlin's marathon (2017), met the inclusion criteria. 4 different groups were created based on sex and performance. Men: Elite (<02:19:00 h), Top 1 (<02:30:00 h), Top 2 (<02:45:00 h) and Top 3 (<03:00:00 h); women: Elite (02:45:00 h), Top 1 (<03:00:00 h), Top 2 (<03:15:00 h), Top 3 (<03:30:00 h). With the aim of comparing the pacing between sex and performance the average speed was normalized. In men, no statistically significant changes were found between performance group and splits. A large number of significant differences between splits and groups were found amongst women: 5-10 km Top 2 vs Top 3 (P = 0.0178), 10-15 km Top1 vs Top 2 (P = 0.0211), 15-20 km Top1 vs Top 2 (P = 0.0382), 20-21.1 km Elite vs Top 2 (P = 0.0129); Elite vs Top 3 (P = 0.0020); Top1 vs Top 2 (P = 0.0233); Top 1 vs Top 3 (P = 0.0007), 25-30 km Elite vs Top 2 (P = 0.0273); Elite vs Top 3 (P = 0.0156), 30-35 km Elite vs Top 2 (P = 0.0096); Top 1 vs Top 2 (P = 0.0198); Top2 vs Top3 (P = 0.0069). In men there were little significant differences based on athletes' performance which implied a similar pacing behaviour. Women presented numerous differences based on their performance which suggested different pacing behaviours.

Affective Feelings and Perceived Exertion During a 10-km Time Trial and Head-to-Head Running Race

PURPOSE

To verify the affective feelings (AFs) and rating of perceived exertion (RPE) responses during a 10-km competitive head-to-head (HTH) running race and compare them with a time-trial (TT) running race.

METHODS

Fourteen male runners completed 2 × 10-km runs (TT and HTH) on different days. Speed, RPE, and AF were measured every 400 m. For pacing analysis, races were divided into the following 4 stages: first 400 m (F400), 401-5000 m (M1), 5001-9600 m (M2), and the last 400 m (final sprint).

RESULTS

Improvement of performance was observed (39:32 [02:41] min:s vs 40:28 [02:55] min:s; P = .03; effect size = -0.32) in HTH compared with TT. There were no differences in either pacing strategy or RPE between conditions. AFs were higher during the HTH, being different in M2 compared with TT (2.09 [1.81] vs 0.22 [2.25]; P = .02; effect size = 0.84).

CONCLUSIONS

AFs are directly influenced by the presence of opponents during an HTH race, and a more positive AF could be involved in the dissociation between RPE and running speed and, consequently, the overall race performance.

Marques M. Effects of Knowing the Task's Duration on Soccer Players' Positioning and Pacing Behaviour During Small-Sided Games

The study aimed to identify how the manipulation of knowledge regarding a training task duration constrains the pacing and tactical behaviour of soccer players when playing small-sided games (SSG). Twenty professional and experienced soccer players participated in a cross-sectional field study using three conditions: not informed on the duration of the SSG, which ended after 20 min (Unknown Condition); briefed about playing the SSG for 10 min, but after they completed the 10-min game, they were requested to complete another 10 min (Partial Condition) and informed before that they would play for 20 min (Known Condition). A global positioning system was used to measure the total distance covered and distances of different exercise training zones (walking to sprinting) and to access the dynamic players positioning through the distance from each player to all the teammates and opponents. Additionally, approximate entropy was measured to identify the regularity pattern of each gathered individual variable. The results indicate that the first 10 min of each scenario presented a higher physical impact independently of the initial information. During this time, the tactical behaviour also revealed higher variability. An increase in the distance of the teammates during the second period of 10-min for the Known scenario was also found, which may result from a lower pacing strategy. This study showed that the prior knowledge of the task duration led to different physical and tactical behaviours of the players. Furthermore, the relationship between the physical impact and the regularity of team game patterns should be well analysed by the coach, because the physical impact may be harmful to the development of the collective organization of the team.

Pacing During 200-m Competitive Masters Swimming

Breen, D, Powell, C, and Anderson, R. Pacing during 200-m competitive masters swimming. J Strength Cond Res 34(7): 1903-1910, 2020-Pacing strategies are key to overall performance outcome, particularly in swimming given the large resistive properties of water. However, no studies examining how swimming stroke, gender, age, or performance level affect pacing strategies during 200-m races. This study aimed to examine masters athletes pacing strategies categorized by stroke, gender, age, and performance level. Data were retrieved from World and European masters swimming championships and contained data for 4,272 performances. Performances were coded for stroke, gender, age, and performance classification (PC). Performance classification was based on comparison to the appropriate masters world record. Performances were then normalized, with split times being expressed as a percentage faster or slower than average 50-m split time to determine relative pace. Coefficient of variation (CV) of 50-m time was examined across splits. The main effect for stroke was examined at each split, whereas gender, age, and PC were examined for split-1 pace and CV. An alpha level of 0.05 was set to denote statistical significance. A main effect for stroke was identified at each split (all p < 0.001; (Equation is included in full-text article.)-split-1 = 0.292; (Equation is included in full-text article.)-split-2 = 0.040; (Equation is included in full-text article.)-split-3 = 0.058; (Equation is included in full-text article.)-split-4 = 0.162). A main effect for PC was identified for split-1 pace and CV within all strokes (all p < 0.001), except for breaststroke (both p > 0.775). Masters athletes exhibit different pacing patterns across strokes, whereas lower ranked athletes also display less even pacing and a faster relative start compared with higher-ranked athletes. Individual analyses of pacing strategies may be necessary.

Head-to-head competition does not affect pacing or performance in 1 km cycling time trials

Previous research has shown enhanced performance and altered pacing behaviour in the presence of a virtual opponent during middle-distance cycling time trials with a duration of 2 min and longer. The purpose of this study was to determine whether these effects are also present in cycling time trials of shorter duration. Twelve physically active men completed three 1-km time trials. After a familiarisation trial (FAM), participants performed two experimental conditions: one without opponent (NO) and one with a virtual opponent (OP). Repeated-measures ANOVAs were used to assess differences in pacing and performance using power output and duration (p<0.05). No differences in mean finishing times (FAM: 91.5 ± 7.7 s; NO: 91.6 ± 6.4 s; OP: 90.9 ± 4.9 s; p=0.907) or power output (FAM: 382 ± 111 W; NO: 363 ± 80 W; OP: 367 ± 67; p=0.564) were found between experimental conditions. Furthermore, no differences in pacing profiles between experimental conditions were found (p=0.199). Similarly, rate of perceived exertion did not differ between experimental conditions at any moment (p=0.831). In conclusion, unlike events of a more prolonged duration (>2 min), the presence of an opponent did not affect participants' pacing behaviour in short duration 1-km time trials.

How to Train Your Health: Sports as a Resource to Improve Cognitive Abilities in Cancer Patients

From a cognitive-psychological perspective, physical exercise (PE) and sports are an interesting tool for improving people's cognitive abilities. One field of application for such a tool is decision making (DM) support in chronic patients, cancer patients, and survivors in particular. On the one hand, cancer patients and survivors have to continually take important decisions about their own care (e.g., treatment choice; changes in lifestyle), in collaboration with caregivers and health providers; on the other hand, side effects of treatment may be detrimental to cognitive abilities, such as attention, which make the health DM tasks even more demanding, complex, and emotionally disruptive for patients. Since cancer patients have to engage in healthy activities both for improving their own quality of life and for sustaining the effects of medications, clinical advice to engage in sport and PE is becoming more and more widespread within interventions. However, while sports are usually seen as healthy physical activities, their impact on cognitive abilities is mostly overlooked in the literature. The hypothesis of the present work is that sports could be fully exploited in their potential as focused exercises for cognitive ability training, in the field of cognitive training for chronic patients specifically. Indeed, literature shows that different sports (e.g., individual or team-based) influence and possibly augment cognitive abilities such as focused and divided attention, working memory, and DM under time constraints. Moreover, besides providing training for cognitive abilities, the experience of sports may represent an opportunity to explore, train and sharpen DM abilities directly: we identify five ways in which sport experiences may influence DM processes, and provide indications for future research on the topic.

Lane and Heat Draw Have Little Effect on Placings and Progression in Olympic and IAAF World Championship 800 m Running

The aim of this study was to establish whether the lane and heat draw influenced placings and progression in world-class 800-m track running. Finishing positions and times of 1,086 performances at the Olympic Games and IAAF World Championships between 1999 and 2017 were obtained. Mean finishing and season's best times (SB), as well as placings and progression rates, were found for each heat number and for the inner (Lanes 1 and 2), middle (Lanes 3-6), and outer lanes (Lanes 7 and 8). In the qualifying heats and semi-finals, the theoretically expected number of fastest losers (non-automatic qualifiers) per heat was compared with the actual number. One-way ANOVA with Bonferroni post-hoc tests were conducted to compare finishing times between lane and heat numbers across rounds. With regard to the order of heats, there were no differences between finishing times in either the qualifying heats or semi-final rounds for men; in the women's event, only Semi-final 3 was the quickest, but still did not have higher progression rates. SB times did not differ between heats within each round, highlighting the fair distribution of athletes. Progression rates for each lane during the qualifying heats ranged between 36 and 52% (men) and between 49 and 61% (women), close to the expected ranges of 45 and 55%, respectively. The middle lanes were quicker in the seeded semi-finals and finals only. Men in the outer lanes fared slightly worse and should focus on achieving the optimal tactical position after breaking from lanes. The IAAF could reconsider how they allocate seeded lanes in the later rounds by switching the fifth and sixth fastest athletes from the outer to the inner lanes. Regarding the heat draw, athletes mostly did not take advantage of knowing previous performances from earlier races, and probably focused on achieving an automatic qualifying position instead. However, the fastest losers in the women's last semi-final were faster and showed that benefitting from the heat draw is possible with tactical coaching.

Characterization of performance fatigability during a self-paced exercise

Pacing during a high-intensity cycling time trial (TT) appears to prevent premature task failure, but the performance fatigability during a self-paced exercise is currently unknown. Therefore, the current study characterized the time course of performance fatigability during a 4-km TT. Eleven male cyclists performed three separated TTs in a crossover, counterbalanced design. The TTs lasted until the end of the fast-start (FS; 600 ± 205 m), even-pace (EP; 3,600 ± 190 m), and end-spurt (ES; 4,000 m) phases. Performance fatigability was characterized by using isometric maximal voluntary contractions (IMVCs), whereas the muscle activation [i.e., voluntary activation (VA)] and contractile function of knee extensors [e.g., peak torque of potentiated twitches (TwPt)] were evaluated using electrically evoked contractions performed before and 1 min after each specific part of the trial. Gas exchange, power output (PO), and electromyographic activity (EMG) were also recorded. EMG/PO showed an abrupt increase followed by a continuous decrease toward the end of FS, resulting in a drop in IMVC (−12%), VA (−8%), and TwPt (−23%). EMG/PO was stable during EP, with no additional drop on IMVC, VA, or TwPt (−12%, −6%, and −22%, respectively). EMG/PO increased abruptly during the ES, but there was no change in IMVCs, VA, or TwPt (−13%, −8%, and −26%, respectively). These findings demonstrate that the performance fatigability during a self-paced exercise is characterized by a large drop in contractile function and muscle activation at the beginning of the trial (i.e., FS), without additional change during the middle and end phases (i.e., EP and ES).

NEW & NOTEWORTHY The time course of performance fatigability throughout a self-paced exercise is currently unknown. The results showed that a large amount of muscle activation and contractile function impairments are attained early on a self-paced exercise (first ∼15% of the total time trial distance) and maintained throughout the test. This novel finding characterizes the performance fatigability from a contractile function and muscle activation perspective, which brings new insights for future studies focused on real-world exercise training and competition.

The Effect of Self-Paced and Prescribed Interset Rest Strategies on Performance in Strength Training

Purpose: To assess pacing strategies using prescribed and self-selected interset rest periods and their influence on performance in strength-trained athletes. Methods: A total of 16 strength-trained male athletes completed 3 randomized heavy strength-training sessions (5 sets and 5 repetitions) with different interset rest periods. The interset rest periods were 3 min (3MIN), 5 min (5MIN), and self-selected (SS). Mechanical (power, velocity, work, and displacement), surface electromyography (sEMG), and subjective (rating of perceived exertion) and readiness-to-lift data were recorded for each set. Results: SS-condition interset rest periods increased from sets 1 to 4 (from 207.52 to 277.71 s; P = .01). No differences in mechanical performance were shown between the different interset rest-period conditions. Power output (210 W; 8.03%) and velocity (0.03 m·s−1; 6.73%) decreased as sets progressed for all conditions (P < .001) from set 1 to set 5. No differences in sEMG activity between conditions were shown; however, vastus medialis sEMG decreased as the sets progressed for each condition (1.75%; P = .005). All conditions showed increases in rating of perceived exertion as sets progressed (set 1 = 6.1, set 5 = 7.9; P < .001). Participants reported greater readiness to lift in the 5MIN condition (7.81) than in the 3MIN (7.09) and SS (7.20) conditions (P < .001). Conclusions: Self-selecting interset rest periods does not significantly change performance compared with 3MIN and 5MIN conditions. Given the opportunity, athletes will vary their interset rest periods to complete multiple sets of heavy strength training. Self-selection of interset rest periods may be a feasible alternative to prescribed interset rest periods.

Psycho-physiological responses to perceptually-regulated interval runs in hypoxia and normoxia

We investigated whether perceptually-regulated high-intensity intervals in hypoxia are associated with slower running velocities versus normoxia, when physiological responses and exercise-related sensations remain the same. Nineteen trained runners (33.4 ± 9.1 years) completed a high-intensity interval running protocol (4 × 4-min intervals at a clamped perceived rating exertion of 16 on the 6-20 Borg scale, 3-min passive recoveries) in either hypoxic (HYP; FiO₂ 15.0%) or normoxic (NOR; FiO₂ 20.9%) conditions. Participants adjusted to a progressively slower running velocity from interval 1-4 (-7.0%), and more so in HYP vs. NOR for intervals 2, 3 and 4 (-4.6%, -6.4% and - 7.9%, respectively; p < .01). Heart rate increased from interval 1-4 (+4.8%; p < .01), independent of condition. Arterial oxygen saturation was lower in HYP vs. NOR (86.0% vs. 94.8%; p < .01). Oxyhemoglobin (-23.7%) and total hemoglobin (-77.0%) decreased, whilst deoxyhemoglobin increased (+44.9%) from interval 1-4 (p < .01), independent of condition. Perceived recovery (-41.6%) and motivation (-21.8%) were progressively lower from interval 1-4, and more so in HYP vs. NOR for intervals 2, 3 and 4 (recovery: -8.8%, -24.2% and - 29.3%; motivation: -5.3%, -20.3% and - 22.4%, respectively; p < .01). Perceived breathlessness (+18.6%), limb discomfort (+44.0%) and pleasure (-32.2%) changed from interval 1-4, with significant differences (+21.8%, +11.3% and - 31.3%, respectively) between HYP and NOR (p < .01). Slower interval running velocities in hypoxia achieve similar heart rate and muscle oxygenation responses to those observed in normoxia when perceptually-regulated, yet at the expense of less favourable exercise-related sensations.

Perceived Impact as the Underpinning Mechanism of the End-Spurt and U-Shape Pacing Patterns

The end-spurt and U-shape reflect common pacing patterns across a variety of fields (e.g., running, swimming, cycling). To date, however, the literature lacks a clear, parsimonious account for these effects. Here, I propose these pacing patterns can be accounted for by a psychological mechanism termed perceived impact. As athletes perceive their actions to better affect task-progress, they become more motivated and perform better accordingly. To illustrate, if an athlete has five more laps to go during a race, completing the current lap closes 20% of the remaining distance. Alternatively, when she has two more laps to go, the current lap closes 50% of the remaining distance. In the latter case, the impact of completing a single lap on task-progress is perceived to be higher. Her motivation will increase accordingly near the end of the track - giving rise to an end-spurt. I demonstrate the mechanism's predictive power by reproducing previous findings through simulations. I then move to discuss how this framework is theoretically insightful in view of previous accounts such as the Central Governor Model and the Psyco-Biological Model. I conclude this work with applied strategies for practitioners in their daily routines.

In-season internal and external training load quantification of an elite European soccer team

Elite soccer teams that participate in European competitions need to have players in the best physical and psychological status possible to play matches. As a consequence of congestive schedule, controlling the training load (TL) and thus the level of effort and fatigue of players to reach higher performances during the matches is therefore critical. Therefore, the aim of the current study was to provide the first report of seasonal internal and external training load that included Hooper Index (HI) scores in elite soccer players during an in-season period. Nineteen elite soccer players were sampled, using global position system to collect total distance, high-speed distance (HSD) and average speed (AvS). It was also collected session rating of perceived exertion (s-RPE) and HI scores during the daily training sessions throughout the 2015-2016 in-season period. Data were analysed across ten mesocycles (M: 1 to 10) and collected according to the number of days prior to a one-match week. Total daily distance covered was higher at the start (M1 and M3) compared to the final mesocycle (M10) of the season. M1 (5589m) reached a greater distance than M5 (4473m) (ES = 9.33 [12.70, 5.95]) and M10 (4545m) (ES = 9.84 [13.39, 6.29]). M3 (5691m) reached a greater distance than M5 (ES = 9.07 [12.36, 5.78]), M7 (ES = 6.13 [8.48, 3.79]) and M10 (ES = 9.37 [12.76, 5.98]). High-speed running distance was greater in M1 (227m), than M5 (92m) (ES = 27.95 [37.68, 18.22]) and M10 (138m) (ES = 8.46 [11.55, 5.37]). Interestingly, the s-RPE response was higher in M1 (331au) in comparison to the last mesocycle (M10, 239au). HI showed minor variations across mesocycles and in days prior to the match. Every day prior to a match, all internal and external TL variables expressed significant lower values to other days prior to a match (p<0.01). In general, there were no differences between player positions. Conclusions: Our results reveal that despite the existence of some significant differences between mesocycles, there were minor changes across the in-season period for the internal and external TL variables used. Furthermore, it was observed that MD-1 presented a reduction of external TL (regardless of mesocycle) while internal TL variables did not have the same record during in-season match-day-minus.