Muscle pain induced by hypertonic saline in the knee extensors decreases single-limb isometric time to task failure.

PURPOSE: Increased nociceptive activity and the experience of exercise-induced pain (EIP) may contribute to fatigue during endurance exercise. To investigate this, a pain model that produces pain similar to EIP and decouples its relationship to exercise intensity is required. This study (1) compared the quality of pain caused by a hypertonic saline injection into the vastus lateralis in resting and exercise conditions, and (2) investigated whether this pain contributes to changes in time to task failure. METHODS: On separate days, 18 participants completed a time to task failure at 20% maximal voluntary torque (MVT), a resting hypertonic saline intramuscular injection, and in a further three visits a time to task failure at 10% MVT following injection of isotonic saline, hypertonic saline or a control (no injection). RESULTS: In a subset of eligible participants (n = 12), the hypertonic saline combined with 10% MVT produced a qualitative experience of pain (assessed by the McGill Pain Questionnaire) that felt similar to EIP. 10% MVT with hypertonic saline significantly elevated pain intensity in the first 20% of the time to task failure and caused a significantly (P < 0.05) shorter time to task failure (448 ± 240 s) compared with the isotonic saline (605 ± 285 s) and control (514 ± 197 s) conditions. CONCLUSION: These findings demonstrate that hypertonic saline increases the intensity of pain during exercise, which results in a faster occurrence of exercise-induced fatigue. These results provide important evidence supporting pain as a limiting factor in endurance performance.

Towards a three-dimensional framework of centrally regulated and goal-directed exercise behaviour: a narrative review.

The Central Governor Model (CGM) ignited a paradigm shift from concepts of catastrophic failure towards central regulation of exercise performance. However, the CGM has focused on the central integration of afferent feedback in homeostatic control. Accordingly, it neglected the important role of volitional self-regulatory control and the integration of affective components inherently attached to all physiological cues. Another limitation is the large reliance on the Gestalt phenomenon of perceived exertion. Thus, progress towards a comprehensive multidimensional model of perceived fatigability and exercise regulation is needed. Drawing on Gate Control Theory of pain, we propose a three-dimensional framework of centrally regulated and goal-directed exercise behaviour, which differentiates between sensory, affective and cognitive processes shaping the perceptual milieu during exercise. We propose that: (A) perceived mental strain and perceived physical strain are primary determinants of pacing behaviour reflecting sensory-discriminatory processes necessary to align planned behaviour with current physiological state, (B) core affect plays a primary and mediatory role in exercise and performance regulation, and its underlying two dimensions hedonicity and arousal reflect affective-motivational processes triggering approach and avoidance behaviour, and (C) the mindset-shift associated with an action crisis plays a primary role in volitional self-regulatory control reflecting cognitive-evaluative processes between further goal-pursuit and goal-disengagement. The proposed framework has the potential to enrich theory development in centrally regulated and goal-directed exercise behaviour by emphasising the multidimensional dynamic processes underpinning perceived fatigability and provides a practical outline for investigating the complex interplay between the psychophysiological determinants of pacing and performance during prolonged endurance exercise.

Modelling the process of falling behind and its psychophysiological consequences.

INTRODUCTION: A preceding article investigated the psychophysiological responses to falling behind a performance matched opponent. The following temporally linked cause-effect relationships were hypothesised: falling behind precedes deterioration in valence, deterioration in valence precedes development of an action crisis, experience of an action crisis precedes psychoneuroendocrinological distress response and non-adaptive distress response reduces conduciveness to high performance, thereby preceding performance decrement. METHODS: In this article, we applied structural equation modelling to test the extent to which the observed data fit the hypothesised cause-effect relationships. A five-step procedure was applied to model the interrelationships between the major study variables in the hypothesised temporal order. RESULTS: Significant linear relationships were found between all hypothesised predictor and outcome variable pairs (p<0.024). The dynamic change in valence was a significant mediator (p=0.011) as it explained 35% of the relationship between falling behind and action crisis. All hypothesised cause-effect relationships continued to be significant after controlling for performance, descriptor, training and perceived strain variables. The observed data fitted the hypothesised structural model well with excellent model fit indices throughout. CONCLUSION: We applied, tested and confirmed the hypothesised debilitative psychophysiological processes that unfold in response to falling behind a performance matched opponent. The main findings were: deterioration in valence mediated the relationship between falling behind and action crisis, the mindset shift associated with an action crisis predicted increased blood cortisol concentrations and non-adaptive blood cortisol concentrations predicted performance decrement. The findings point towards the crucial role of affective and cognitive modifiers in centrally regulated and goal-directed exercise behaviour.

The Effect of Maturation on Performance During Repeated Sprints With Self-Selected Versus Standardized Recovery Intervals in Youth Footballers.

PURPOSE: The purpose of this experiment was to assess performance during repeated sprints utilizing self-selected recovery intervals in youth football (soccer) players at different stages of maturation. METHODS: Quota sampling method was used to recruit 14 prepeak height velocity (PHV) and 14 post-PHV participants for the study (N = 28; age = 13 [0.9] y, stature = 162.5 [10.8] cm, mass = 50.2 [12.7] kg). Players performed repeated sprints comprising 10 × 30 m efforts under 2 experimental conditions: using 30-second and self-selected recovery intervals. Magnitude of effects for within- and between-group differences were reported using effect size (ES) statistics ± 90% confidence intervals and percentage differences. RESULTS: The decline in sprint performance was likely lower in the pre-PHV compared with the post-PHV group during the standardized recovery trial (between-group difference = 37%; ES = 0.41 ± 0.51), and likely lower in the post-PHV group during the self-selected recovery trial (between-group difference = 50%; ES = 0.45 ± 0.54). Mean recovery duration was likely shorter in the pre-PHV compared with the post-PHV group during the self-selected recovery trial (between-group difference = 26.1%; ES = 0.47 ± 0.45). CONCLUSION: This is the first study to show that during repeated sprints with self-selected recovery, pre-PHV children have an impaired ability to accurately interpret physical capabilities in the context of the task compared with post-PHV adolescents.

The Cardiac Rehabilitation Inventory: A New Method of Tailoring Patient Support.

BACKGROUND: Uptake and adherence to cardiac rehabilitation (CR) are low, and a contributing factor to this may be the practical difficulties of providing a tailored CR environment suited to individual preferences and needs. OBJECTIVE: The aim of this study was to develop and test a short questionnaire that CR practitioners can use to understand individual patient need and tailor support accordingly. METHODS: A conceptual framework of engagement in CR was derived from a comprehensive literature review and the content analysis of semistructured interviews with 15 CR patients. The conceptual framework was used to construct the first version of the Cardiac Rehabilitation Inventory (CRI), which comprised 42 items. Responses on the CRI were measured using a 5-point Likert scale. The CRI was administered to 380 phase III and IV CR patients, and factor analysis (FA) was used to identify salient CR engagement factors. RESULTS: The simplest structure found using FA was three 6-item subscales that all had good levels of internal consistency (Cronbach's α) and were labeled (a) outcome anxiety, α = .726; (2) process anxiety, α = .724; and (3) autonomy, α = .653. The 3-factor CRI model was verified using confirmatory FA (CMin/df = 3.2, root-mean-square error of approximation = 0.073). Attenders were found to have higher levels of outcome anxiety than nonattenders (P < .001), and precontemplator nonattenders were found to have lower autonomy compared with attenders (P < .001). Standard multiple regression analysis indicated outcome anxiety was a strong predictor of CR intentions (r = 0.716), followed by autonomy (r = 0.110) and process anxiety (r = 0.031). CONCLUSIONS: The CRI is a reliable method of measuring CR outcome anxiety, process anxiety, and autonomy. These CRI measurements provide rehabilitation practitioners with valuable information that can help provide individual tailored support.

Correlates of Mood and RPE During Multi-Lap Off-Road Cycling.

This study examined the relationship between mood and rating of perceived exertion (RPE) during a simulated multiple-lap time trial (MLTT). Nineteen male cyclists performed a MLTT consisting of four 9.9 km laps, each lap with a gradient ranging from 0 to 10 %. Mood as measured by the Profile of Mood States Questionnaire (POMS) and perceived exertion as measured by the Borg CR100 scale (RPE) were obtained at the end of each lap. A categorical multiple regressive model, having median of POMS subscales as independent variables, was obtained to explain the variance in median RPE responses. Increases in POMS fatigue scores and decreases in POMS vigour scores were observed throughout the MLTT (P < 0.001). A linear increase in RPE during the MLTT was also observed (P < 0.001). POMS fatigue subscale scores accounted for 88 % of the variance in RPE during the MLTT (R(2) = 0.88, P = 0.002), and no other POMS subscale improved the final predictive model. With the exception of fatigue these results suggest that most aspects of mood do not have a discernable effect on RPE during a MLTT. The rate of increase in RPE can predict the MLTT endpoint.

Occlusion of sight, sound and smell during Green Exercise influences mood, perceived exertion and heart rate.

This study's aim was to identify the relative contribution of sight, sound and smell to the Green Exercise effect. It was hypothesised that visual occlusion while exercising in a natural environment would have the greatest diminishing effect on perceived exertion and mood compared to auditory and olfactory occlusion. Twenty-nine healthy participants were randomly assigned to one of the three groups: visual (n = 10), auditory (n = 9) and olfactory occlusion (n = 10). Each performed six, 5-min bouts of exercise alternating between full sensory and occlusion. Rate of perceived exertion (RPE), heart rate (HR) and mood were recorded at the end of each bout. Sensory-occlusion increased mood, RPE and HR; effects were strongest when sounds were blocked but virtually absent when vision was blocked. During sensory occlusion, mood changes were characterised by increased Fatigue and Confusion, and reduced Vigour. Reductions in Tension and Vigour and increases in Fatigue were found during full sensory exercise, consistent with previous research findings.

Association between habitual school travel and muscular fitness in youth.

OBJECTIVE: To determine whether active school travel is associated with muscular fitness, which is an emerging marker of youth health. METHODS: Handgrip strength, vertical jump and vertical jump peak power were measured in n=6829 English schoolchildren (53% males, age 12.9 ± 1.2 years) between 2007 and 2011. Participants were grouped according to self-reported habitual school travel modality. RESULTS: Cyclists had greater handgrip strength than passive travelers. Vertical jump height was greater in walkers and cyclists compared with passive travelers. Jump peak power was also higher in walkers than in the passive travel group. Compared with passive travelers, cyclists had a higher (age, sex and BMI-adjusted) likelihood of good handgrip strength (OR 1.42, 95%CI;1.14-1.76) and walkers were more likely to have good measures for vertical jump peak power (OR 1.14, 95%CI;1.00-1.29). Cyclists' likelihood of having good handgrip strength remained significantly higher when adjusted for physical activity (OR 1.29, 95%CI;1.08-1.46). CONCLUSION: Muscular fitness differs according to school travel habits. Cycling is independently associated with better handgrip strength perhaps due to the physical demands of the activity. Better muscular fitness may provide another health-related reason to encourage active school travel.

The effects of 7-week participation in football on personal well-being among male asylum seekers in a UK hotel.

Background: This study examines the impact of participating in a seven-week football programme on the personal well-being of male asylum seekers residing in contingency accommodation in the UK. Methods: This repeated measures study included a cohort of participants who engaged in weekly football sessions and completed a well-being questionnaire (ONS4) over a continuous seven-week period. Longitudinal linear regression analysis using generalized estimating equations (GEE) was used to assess the relationship between personal well-being and weekly minutes of football participation (M1). A second model incorporating the total number of non-football activity sessions in the past week as a covariate was also implemented (M2). Results: Of the 73 participants who completed the questionnaire, 23 responded twice or more across the study period and were subsequently included in the analysis. Results revealed that 2 h of football participation within 7 days significantly improved aspects of personal well-being when compared with no football participation, including improved life satisfaction, feeling life is worthwhile, and happiness. Both models demonstrated a shift from 'low' to 'medium' ONS4 categorical score. Anxiety levels remained unchanged regardless of participation and model. Conclusion: We provide important evidence on the potential benefits of football participation for promoting personal well-being among male asylum seekers residing in contingency accommodation.

Inner dialogue and its relationship to perceived exertion during different running intensities.

This study examined the effect of low- and high-intensity running on cognitive thoughts (an individual's "inner dialogue") and its relationship to ratings of perceived exertion (RPE). Cognitive thoughts and RPE of eight runners were collected during a 40-min. treadmill run at either a low (50% peak running speed) or a high (70% peak running speed) exercise intensity. Runners were asked to place their thoughts into one of 10 themed categories, which incorporated a broad association/dissociation classification (Schomer, 1986, 1987). At a low intensity and RPE (6-10), runners reported more dissociative thoughts, while at a high intensity and RPE (16-20) they reported more associative thoughts. Further, although the runners may report a particular RPE, the inner dialogue and description of perceived exertion and fatigue may be markedly different. These findings suggest that an athlete's "internal dialogue" is intensity dependent, and may relate to the more urgent need to self-monitor physical changes and sensations during high-intensity running.

Redirected Attention and Impaired Recognition Memory during Exhaustive Cycling Has Implications for Information Processing Models of Effort-Regulation.

Perception of internal and external cues is an important determinant of pacing behaviour, but little is known about the capacity to attend to such cues as exercise intensity increases. This study investigated whether changes in attentional focus and recognition memory correspond with selected psychophysiological and physiological parameters during exhaustive cycling. METHODS: Twenty male participants performed two laboratory ramped cycling tests beginning at 50 W and increasing by 0.25 W/s until volitional exhaustion. Ratings of perceived exertion, heart rate and respiratory gas exchange measures were recorded during the first test. During the second test, participants listened to a list of spoken words presented through headphones at a rate of one word every 4 s. Afterwards, their recognition memory for the word pool was measured. RESULTS: Recognition memory performance was found to have strong negative correlations with perceived exertion (p < 0.0001), percentage of peak power output (p < 0.0001), percentage of heart rate reserve (p < 0.0001), and percentage of peak oxygen uptake (p < 0.0001). CONCLUSIONS: The results show that, as the physiological and psychophysiological stress of cycling intensified, recognition memory performance deteriorated. This might be due to impairment of memory encoding of the spoken words as they were presented, or because of a diversion of attention away from the headphones, perhaps towards internal physiological sensations as interoceptive sources of attentional load increase with exercise intensity. Information processing models of pacing and performance need to recognise that an athlete's capacity to attend to and process external information is not constant, but changes with exercise intensity.

Visual color perception in green exercise: positive effects on mood and perceived exertion.

Positive effects of green exercise on physical and psychological wellbeing have been found, yet little is known about the underlying cognitive mechanisms responsible for such effects. The purpose of this visual sensation study was to establish the extent to which the color green, as a primitive visual feature of many natural environments, contributes to the green exercise effect. Fourteen participants performed three moderate-intensity 5-min cycling tasks (50% peak power output) while watching video footage of a rural cycling course that simulated cycling through a real natural environment. The three randomly counter-balanced video conditions were unedited (V(GREEN)), achromatic (V(GRAY)) or red filter (V(RED)). Lower total mood disturbance and ratings of perceived exertion were found during the V(GREEN) compared to V(GRAY) and V(RED). Feelings of anger were higher after V(RED) compared to the other conditions. Feelings of tension, depression, fatigue, vigor, and confusion did not differ among conditions. This is the first study to show that the color green, as a primitive feature of visual sensation, has a contributory effect toward positive green exercise outcomes.

Optic flow influences perceived exertion during cycling.

Optic flow on the retina creates a perception of a person's movement relative to their surroundings. This study investigated the effect of optic flow on perceived exertion during cycling. Fifteen participants completed a 20-km reference cycling time trail in the fastest possible time followed by three randomly counterbalanced 20-km cycling trials. Optic flow, via projected video footage of a cycling course, either represented actual speed (TTNORM) or was varied by -15% (TTSLOW) and +15% (TTFAST). During TTSLOW, power output and ratings of perceived exertion (RPE), measured every 4 km, were lower during TTSLOW compared with TTNORM and TTFAST. There were no differences in heart rate or cadence. This study is the first to show that different rates of optic flow influence perceived exertion during cycling, with slower optic flow being associated with lower RPE and higher power output.

Observer effects on the rating of perceived exertion and affect during exercise in recreationally active males.

This study examined the effect of introducing either a male or female observer on the ratings of perceived exertion (RPE) and affect of male runners during a moderate intensity running task. 10 moderately active men completed three 20-min. moderate intensity running trials at 60% of their peak treadmill running speed. Each participant completed three trials in random order: control, male-observed, and female-observed, where either the male or female observer joined the trial after 10 min. of the trial had elapsed, during which RPE and affect were monitored. The introduction of a female observer caused a significant decrease in RPE, whereas the introduction of a male observer caused a significant increase in RPE compared to the control trial. Affect was higher in the presence of both a male and female observer compared to control. It was concluded that there is a social, interpersonal, psychological dimension to RPE during exercise.

Cognition and performance: anxiety, mood and perceived exertion among Ironman triathletes.

OBJECTIVE: The authors examined the changing patterns of mood before and after an Ironman triathlon, and the relationships between expected performance outcomes, perception of effort and pacing. DESIGN: Twelve participants in the 2008 Ironman Austria triathlon competition were studied before, during and after the event. Each participant completed measures of mood, anxiety and perceived exertion, while pacing was calculated from official race timings at various points on the course. RESULTS: Positive correlations were found between distance covered and rating of perceived exertion (RPE) during each of the individual disciplines, and also between RPE and the percentage of overall race time completed (r=0.826, p<0.001). A negative correlation was found between average speed and distance covered during the run segment (r=-0.911, p<0.005) with pace gradually declining. Differences occurred in the profile of mood states mood subscales of tension and fatigue between the baseline, prerace and postrace trials. Somatic anxiety was higher before the race compared with baseline measures. DISCUSSION: RPE followed a linear progression of RPE during each discipline followed by a re-setting of the perception of effort at the start of the next discipline. The increase in RPE for the entire event followed a linear increase. The linear decline in run pace is consistent with a recent model in which expected RPE is used to modulate pacing. Anxiety and mood responses of participants in this study indicate that the emotional response of athletes before and after ultra-endurance exercise is closely aligned with their conscious thoughts.

Muscle pain from an intramuscular injection of hypertonic saline increases variability in knee extensor torque reproduction.

The intensity of exercise-induced pain (EIP) reflects the metabolic environment in the exercising muscle, so during endurance exercise, this may inform the intelligent regulation of work rate. Conversely, the acute debilitating effects of EIP on motor unit recruitment could impair the estimation of force produced by the muscle and impair judgement of current exercise intensity. This study investigated whether muscle pain that feels like EIP, administered via intramuscular injection of hypertonic saline, interferes with the ability to accurately reproduce torque in a muscle group relevant to locomotive exercise. On separate days, 14 participants completed an isometric torque reproduction task of the knee extensors. Participants were required to produce torque at 15% and 20% maximal voluntary isometric torque (MVIT), without visual feedback before (baseline), during (pain/no pain), and after (recovery) an injection of 0.9% isotonic saline (Control) or 5.8% hypertonic saline (Experimental) into the vastus lateralis of the right leg. An elevated reported intensity of pain, and a significantly increased variance in mean contraction torque at both 15% (P = 0.049) and 20% (P = 0.002) MVIT was observed in the Experimental compared to the Control condition. Both 15 and 20% target torques were performed at a similar pain intensity in the Experimental condition (15% MVIT: 4.2 ± 1.9; 20% MVIT: 4.5 ± 2.2; P > 0.05). These findings demonstrate that the increased muscle pain from the injection of hypertonic saline impeded accurate reproduction of knee extensor torque. These findings have implications for the detrimental impact of EIP on exercise regulation and endurance performance.NEW & NOTEWORTHY We provide novel data demonstrating that the presence of muscle pain interferes with estimations of torque produced by the knee extensors, which could impair judgment of work rate during endurance exercise. The novelty of our study is in the application of the hypertonic saline experimental model into a quadriceps muscle during short, submaximal isometric contractions at an intensity that provides a more translatable assessment of the impact of exercise-induced pain on work-rate regulation during whole body exercise.

French Translation and Validation of the Rating-of-Fatigue Scale.

BACKGROUND: The Rating of Fatigue (ROF) scale can measure changes in perceived fatigue in a variety of contexts. OBJECTIVE: The aim of the present study was to translate and subsequently validate the ROF scale in the French language. METHODS: The study was composed of three phases. Phase 1 involved a comprehensive translation, back-translation, and consolidation process in order to produce the French ROF scale. During phase 2, the face validity of the French ROF scale was assessed. A cohort of 60 native French speaking participants responded to a range of Likert scale items which probed the purposes of the ROF scale and what it is intended to measure. During phase 3, the convergent and divergent validity of the ROF scale was assessed during ramped cycling to exhaustion and 10 min of resting recovery. RESULTS: The results from phase 1 demonstrated comparability and interpretability between the original and back-translated ROF scale. In phase 2, participants reported a high face validity, with a score of 3.48 ± 0.70 out of 4 when given the item probing whether the scale "measures fatigue". This score further improved (3.67 ± 0.57, P = 0.01) after participants read the accompanying instructions. Participants were able to distinguish the purposes of the scale for measuring fatigue rather than exertion. In phase 3, strong correlations were found between ROF and heart rate (HR) both during exercise (r = 0.91, P < 0.01) and recovery (r = 0.92, P < 0.01), while discriminant validity between ROF and rating of perceived exertion (RPE) was found during recovery. CONCLUSION: The present study permits the applications of the ROF scale in the French language.

Athlete-Opponent Interdependency Alters Pacing and Information-Seeking Behavior.

PURPOSE: The influence of interdependency between competitors on pacing decision-making and information-seeking behavior has been explored. This has been done by only altering instructions, and thereby action possibilities, while controlling environment (i.e., competitor behavior) and exercise task. METHODS: Twelve participants performed a 4-km time trial on a Velotron cycle ergometer in a randomized, counterbalanced order alone with no virtual opponent (NO), against a virtual opponent with no restrictions (low athlete-opponent interdependency [OP-IND]), or against a virtual opponent who the participant was permitted to overtake only once during the trial (high athlete-opponent interdependency [OP-DEP]). Information-seeking behavior was evaluated using an SMI eye tracker. Differences in pacing, performance, and information-seeking behavior were examined using repeated-measures ANOVA (P < 0.05). RESULTS: Neither mean power output (NO, 298 ± 35 W; OP-IND, 297 ± 38 W; OP-DEP, 296 ± 37 W) nor finishing time (NO, 377.7 ± 17.4 s; OP-IND, 379.3 ± 19.5 s; OP-DEP, 378.5 ± 17.7 s) differed between experimental conditions. However, power output was lower in the first kilometer of OP-DEP compared with the other experimental conditions (NO, 332 ± 59 W; OP-IND, 325 ± 62 W; OP-DEP, 316 ± 58 W; both P < 0.05), and participants decided to wait longer before they overtook their opponent (OP-IND, 137 ± 130 s; OP-DEP, 255 ± 107 s; P = 0.040). Moreover, total fixation time spent on the avatar of the virtual opponent increased when participants were only allowed to overtake once (OP-IND, 23.3 ± 16.6 s; OP-DEP, 55.8 ± 32.7 s; P = 0.002). CONCLUSION: A higher interdependency between athlete and opponent altered pacing behavior in terms of in-race adaptations based on opponent's behavior, and it induced an increased attentional focus on the virtual opponent. Thus, in the context of exercise regulation, attentional cues are likely to be used in an adaptive way according to their availability and situational relevance, consistent with a decision-making framework based on the interdependence of perception and action.

Perceived Fatigability: Utility of a Three-Dimensional Dynamical Systems Framework to Better Understand the Psychophysiological Regulation of Goal-Directed Exercise Behaviour.

A three-dimensional framework of perceived fatigability emphasises the need to differentiate between the qualitatively distinct inputs of sensory-discriminatory, affective-motivational and cognitive-evaluative processes that shape the perceptual milieu during prolonged endurance exercise. This article reviews the framework's utility to better understand how cause-effect relationships come to be and how perception-action coupling underpins pacing behaviour and performance fatigability. Preliminary evidence supports the hypotheses that perceived strain plays a primary role in trajectory regulation of pacing behaviour, core affect plays a primary and mediatory role in behavioural performance regulation, and the mindset shift associated with an action crisis plays a primary role in the intensity dependent volitional self-regulatory control of conflicting motivational drives. The constructs hypothesised to underpin perceived fatigability are systematically linked, context-dependent, constraint-based, distinguishable and show proportional continuous interdependency. They are further interrelated with dynamic changes in pacing behaviour, performance fatigability and physiological disturbance. Appropriate measurement selections for the subordinate constructs perceived physical strain, perceived mental strain, valence, arousal, action crisis and flow state are discussed. To better understand the non-proportional discontinuous effects of fatigue on discrete shifts in thought states and mindsets, non-linear dynamical systems theory is introduced as an unbiased overarching theory of governing principles in the temporal evolution of complex systems. This provides the opportunity to discuss the bio-psycho-social fatigue phenomenon from a dynamical and holistic perspective. The proposed framework offers a sophisticated alternative to the Gestalt concept of perceived exertion and comprehensively accounts for the psychophysiological processes that determine pacing behaviour and performance. It has the potential to enrich theory development and facilitate a deeper understanding of the psychophysiological regulation of goal-directed exercise behaviour.

The Psychophysiological Determinants of Pacing Behaviour and Performance During Prolonged Endurance Exercise: A Performance Level and Competition Outcome Comparison.

INTRODUCTION: A three-dimensional framework of centrally regulated and goal-directed exercise behaviour emphasised the integration of distinct sensory-discriminatory, affective-motivational and cognitive-evaluative dimensions that underpin perceived fatigability. This study aimed to capture the complex interdependencies and temporal dynamics in these processes, their interrelations with observed pacing behaviour, performance and biochemical variables as well as their performance level- and competition outcome-dependent variances. METHODS: Twenty-three cyclists of distinct performance level categories engaged in individual and head-to-head competition time trials against a performance-matched opponent. Sensory, affective and cognitive processes were respectively assessed with the constructs perceived physical strain and perceived mental strain, valence and felt arousal underpinning core affect and action crisis characterised by a shift from an implemental to a deliberative mindset. RESULTS: Performance level- and competition outcome-dependent variances and differential temporal dynamics in constructs were associated with alterations in pacing behaviour, performance and physiological disturbance. Perceived physical and mental strain were primarily associated with observed pacing behaviour as necessary to align planned behaviour with current physiological state. Valence and arousal were primarily associated with differential responses in performance regulation. The mindset shift associated with an action crisis was primarily associated with non-adaptive, psycho-neuro-endocrinological distress response. CONCLUSION: The proposed constructs are interdependent in a nonlinear dynamic fashion, context dependent, constraint based, distinguishable by well-trained cyclists and interrelated with observed pacing behaviour, performance and physiological disturbance. The proposed framework provides a more comprehensive alternative to the Gestalt concept of perceived exertion and more completely accounts for centrally regulated and goal-directed exercise behaviour.