The role of self-talk in the awareness of physiological state and physical performance

Negative self-talk in runners: Emotional intelligence and perceived stress as explanatory factors

To optimize in the cognitive and emotional processes that appear in stressful situations in sports contexts is a relevant aspect to achieve a high level of performance. The present study aimed to analyze the relationship between perceived stress, emotional intelligence and negative self-talk in runners. It also aimed to determine whether emotional intelligence factors could play a protective role in this relationship. The sample consisted of 1071 runners from a race held in the Basque Country (Spain). The age of the participants was between 18 and 75 years (Mean = 41.59; SD = 9.95; 71.4% men). Participants completed an online survey days after the race. The results showed that perceived stress would be related to greater use of negative self-talk. In addition, evaluation of others' emotions and emotional regulation would also explain the occurrence of negative self-talk. Likewise, the interaction between perceived stress and appraisal of one's own emotions would explain the occurrence of negative self-talk, this relationship being stronger among those with lower scores on appraisal of one's own emotions. Results and practical implications of the findings are discussed.

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.

Type of self-talk matters: Its effects on perceived exertion, cardiorespiratory, and cortisol responses during an iso-metabolic endurance exercise

Self-talk is an effective mental training technique that has been shown to facilitate or debilitate an athlete's performance, depending on its valence. Although the effects of self-talk have been supported by observing change in sport performance, little is known about how self-talk can induce physiological changes. Specifically, it is important to understand if the type of self-talk (positive, neutral, or negative) and can influence stress-related parameters, such as perceived exertion, cardiorespiratory, and cortisol responses. The study's objective was therefore to investigate the top-down effect of positive and negative self-talk compared to a dissociative activity during an iso-metabolic running exercise on autonomic regulation of cardiorespiratory function. Twenty-nine well-trained male runners [38 ± 13 years, 177 ± 7 cm and 73 ± 7 kg] volunteered to participate in a randomized-group design study that included a negative self-talk (NST), a positive self-talk, and a dissociative group (DG). First, participants underwent an incremental running test on a treadmill to determine the maximal oxygen uptake (V̇O_2max ). Next, participants received a mental training session on self-talk and created three positive and three negative self-talk statements. Finally, participants underwent a 60-min steady-state running exercise on a treadmill at 70% of V̇O_2max , during which they were cued at 20-, 35-, and 50-min with their personal self-created positive or negative self-talk statements while the DG listened to a documentary. Cardiorespiratory parameters and rate of perceived exertion (RPE) were recorded throughout the 60-min endurance exercise. In addition, salivary cortisol samples were obtained at waking and after treatment. Although oxygen uptake, carbon dioxide production, RPE, and heart rate significantly changed overtime during the 60-min steady-state running exercise, no significant main treatment effect was found. However, RPE scores, minute ventilation, breathing frequency, and salivary cortisol were significantly higher in the NST group compared to the two other groups. These data suggest that NST [emotion-induced stress, as reflected by elevated cortisol] altered the breathing frequency response. In conclusion, manipulating self-talk alters hormonal response patterns, modulates cardiorespiratory function, and influences perceived exertion.

Developing Self-Awareness in Robots via Inner Speech

The experience of inner speech is a common one. Such a dialogue accompanies the introspection of mental life and fulfills essential roles in human behavior, such as self-restructuring, self-regulation, and re-focusing on attentional resources. Although the underpinning of inner speech is mostly investigated in psychological and philosophical fields, the research in robotics generally does not address such a form of self-aware behavior. Existing models of inner speech inspire computational tools to provide a robot with this form of self-awareness. Here, the widespread psychological models of inner speech are reviewed, and a cognitive architecture for a robot implementing such a capability is outlined in a simplified setup.

Social Support Patterns of Middle-Aged and Older Adults Within a Physical Activity App: Secondary Mixed Method Analysis

Background

Physical activity (PA) is critical for maintaining independence and delaying mobility disability in aging adults. However, 27 to 44% of older adults in the United States are meeting the recommended PA level. Activity trackers are proving to be a promising tool to promote PA adherence through activity tracking and enhanced social interaction features. Although social support has been known to be an influential behavior change technique to promote PA, how middle-aged and older adults use the social interaction feature of mobile apps to provide virtual support to promote PA engagement remains mostly underexplored.

Objective

This study aimed to describe the social support patterns of middle-aged and older adults using a mobile app as part of a behavioral PA intervention.

Methods

Data from 35 participants (mean age 61.66 [SD 6] years) in a 12-week, home-based activity intervention were used for this secondary mixed method analysis. Participants were provided with a Jawbone Up24 activity monitor and an Apple iPad Mini installed with the UP app to facilitate self-monitoring and social interaction. All participants were given an anonymous account and encouraged to interact with other participants using the app. Social support features included comments and likes. Thematic coding was used to identify the type of social support provided within the UP app and characterize the levels of engagement from users. Participants were categorized as superusers or contributors, and passive participants were categorized as lurkers based on the literature.

Results

Over the 12-week intervention, participants provided a total of 3153 likes and 1759 comments. Most participants (n=25) were contributors, with 4 categorized as superusers and 6 categorized as lurkers. Comments were coded as emotional support, informational support, instrumental support, self-talk, and other, with emotional support being the most prevalent type.

Conclusions

Our cohort of middle-aged and older adults was willing to use the social network feature in an activity app to communicate with anonymous peers. Most of our participants were contributors. In addition, the social support provided through the activity app followed social support constructs. In sum, PA apps are a promising tool for delivering virtual social support to enhance PA engagement and have the potential to make a widespread impact on PA promotion.

Trial Registration

ClinicalTrials.gov NCT01869348; https://clinicaltrials.gov/ct2/show/NCT01869348

Optimal Development of Youth Athletes Toward Elite Athletic Performance: How to Coach Their Motivation, Plan Exercise Training, and Pace the Race

Elite athletes have invested many years in training and competition to reach the elite level. One very important factor on the road to elite performance is the decision-making process regarding the regulation of effort over time, termed as pacing behavior. The regulation of effort is vital for optimal athletic performance during a single race and over a longer period of time (e.g., a competitive season) as an inadequate regulation could result in a higher risk of injuries, overtraining, and drop-out. Despite this, there is limited knowledge on how young athletes learn and develop the abilities related to pacing. Pacing behavior of athletes develops from childhood throughout adolescence and is thought to be closely connected to physical maturation, the development of pre-frontal cortical related (meta-) cognitive functions, as well as the gathering of experience with exercise tasks. The motivation of an athlete can critically influence how an athlete paces a single race, but also how they distribute their effort over a longer period of time. Coaches are advised to closely monitor the development of pacing behavior during adolescence (e.g., by gathering split times, and related physiological measurement, during training and competition), as well as the underlying factors including physical maturation (meta-) cognitive development and the motivation of young athletes. Furthermore, pacing behavior development could be aided by providing training in which the task, individual, and environment are manipulated. Hereby, presenting athletes with the opportunity to gain experience in situations which closely resemble the perceptual-motor conditions of upcoming competitions.

To me, to you: How you say things matters for endurance performance

Self-talk enhances physical performance. Nothing is known however about the way that a subtle grammatical difference in self-talk, using first or second person pronouns, may effect performance. As second person self-talk supports self-regulation in non-exercise populations, we hypothesized that 10 km cycling time-trial performance would be superior following second versus first person self-talk. Using a randomized, counterbalanced, crossover design, sixteen physically active males (M_age = 21.99, SD = 3.04 years) completed a familiarization visit followed by a 10 km time-trial during two separate experimental visits using first and second person self-talk. A paired t-test revealed that second person self-talk generated significantly faster time-trial performance than first person self-talk (p = .014). This was reflected in a significantly greater power output throughout the time-trial when using second person self-talk (p = .03), despite RPE remaining similar between conditions (p = .75). This is the first evidence that strategically using grammatical pronouns when implementing self-talk can influence physical performance providing practitioners with a new aspect to consider when developing interventions. We discussed findings in the context of a self-distancing phenomenon induced by the use second person pronouns.

Neural efficiency in basketball players is associated with bidirectional reductions in cortical activation and deactivation during multiple-object tracking task performance

Although sports expertise has been shown to have transferable cognitive benefits, it is unclear how motor expertise influences brain activity during perceptual-cognitive tasks. The aim of the present study was to investigate whether improved perceptual-cognitive behavioral task performance in individuals with well-developed motor skills is associated with characteristic cortical activation and deactivation. Blood oxygenation-level dependent (BOLD) functional MRI (fMRI) was conducted in 23 athletes and 24 age- and education-matched non-athletes performing a multiple object tracking (MOT) task with graded levels of attentional load (two, three, or four targets). Compared to non-athletes, athletes had better performance in the three- and four-target conditions of the MOT task. Less activation of the left frontal eye field (FEF) and bilateral anterior intraparietal sulcus (aIPS) and less deactivation in the bilateral medial superior frontal gyrus (mSFG) were observed in athletes compared to non-athletes. Importantly, as the attentional load was increased, differences in deactivation of the left middle temporal gyrus (MTG) between athletes and non-athletes became larger. Behavioral performance in the high attentional load condition correlated negatively with activation in the left FEF and right aIPS, and correlated positively with that in the mSFG and left MTG. Better performance in elite athletes may transfer from the sport domain to a general cognitive domain owing to higher neural efficiency, which may be represented by a bidirectional reduction phenomenon encompassing both reduced activation of areas associated with task execution and reduced deactivation of areas associated with irrelevant information processing.

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.

Relieving thermal discomfort: Effects of sprayed L-menthol on perception, performance, and time trial cycling in the heat

L-menthol stimulates cutaneous thermoreceptors and induces cool sensations improving thermal comfort, but has been linked to heat storage responses; this could increase risk of heat illness during self-paced exercise in the heat. Therefore, L-menthol application could lead to a discrepancy between behavioral and autonomic thermoregulatory drivers. Eight male participants volunteered. They were familiarized and then completed two trials in hot conditions (33.5 °C, 33% relative humidity) where their t-shirt was sprayed with CONTROL-SPRAY or MENTHOL-SPRAY after 10 km (i.e., when they were hot and uncomfortable) of a 16.1-km cycling time trial (TT). Thermal perception [thermal sensation (TS) and comfort (TC)], thermal responses [rectal temperature (Trec ), skin temperature (Tskin )], perceived exertion (RPE), heart rate, pacing (power output), and TT completion time were measured. MENTHOL-SPRAY made participants feel cooler and more comfortable and resulted in lower RPE (i.e., less exertion) yet performance was unchanged [TT completion: CONTROL-SPRAY 32.4 (2.9) and MENTHOL-SPRAY 32.7 (3.0) min]. Trec rate of increase was 1.40 (0.60) and 1.45 (0.40) °C/h after CONTROL-SPRAY and MENTHOL-SPRAY application, which were not different. Spraying L-menthol toward the end of self-paced exercise in the heat improved perception, but did not alter performance and did not increase heat illness risk.

Improvement of 10-km Time-Trial Cycling With Motivational Self-Talk Compared With Neutral Self-Talk

Purpose:

Unpleasant physical sensations during maximal exercise may manifest themselves as negative cognitions that impair performance, alter pacing, and are linked to increased rating of perceived exertion (RPE). This study examined whether motivational self-talk (M-ST) could reduce RPE and change pacing strategy, thereby enhancing 10-km time-trial (TT) cycling performance in contrast to neutral self-talk (N-ST).

Methods:

Fourteen men undertook 4 TTs, TT1–TT4. After TT2, participants were matched into groups based on TT2 completion time and underwent M-ST (n = 7) or N-ST (n = 7) after TT3. Performance, power output, RPE, and oxygen uptake (VO2) were compared across 1-km segments using ANOVA. Confidence intervals (95%CI) were calculated for performance data.

Results:

After TT3 (ie, before intervention), completion times were not different between groups (M-ST, 1120 ± 113 s; N-ST, 1150 ± 110 s). After M-ST, TT4 completion time was faster (1078 ± 96 s); the N-ST remained similar (1165 ± 111 s). The M-ST group achieved this through a higher power output and VO2 in TT4 (6th–10th km). RPE was unchanged. CI data indicated the likely true performance effect lay between 13- and 71-s improvement (TT4 vs TT3).

Conclusion:

M-ST improved endurance performance and enabled a higher power output, whereas N-ST induced no change. The VO2 response matched the increase in power output, yet RPE was unchanged, thereby inferring a perceptual benefit through M-ST. The valence and content of self-talk are important determinants of the efficacy of this intervention. These findings are primarily discussed in the context of the psychobiological model of pacing.

Emotional responses during repeated sprint intervals performed on level, downhill and uphill surfaces

The purpose of this study was to test emotional responses during sprint intervals performed on a level, down and up surface. Fifty trained participants performed a maximal effort during a 60-m sprint and 10 repetitions of 60 m running sprints on a level, down and up surface on a 5.9% slope. Running speeds, emotional responses and heart rate were measured. Self-selected speeds were correlated with the rating of perceived exertion, the affective balance, the desire to stop and the resources needed for the task in all conditions whereas the pleasure, the desire to continue and the capacity to realise the task were correlated with speeds only during level and uphill running. Mean values of emotional parameters were significantly different (P < 0.05) during running on a flat surface, downhill and uphill. When the gradient of running surface is changed, the pattern of emotional responses was just translated, i.e. most of the slope between the evolution of emotional parameters and the repetitions were not significantly different whereas Y-intercepts were different. Consented effort is highly correlated with the resources needed for the task (P < 0.001, r(2) = 0.72). We propose that the difference in the resources needed for the task between level, downhill and uphill running (F 2, 1499 = 166.5, P < 0.001, Eta(2) = 0.18) is the most important key that explains our results.

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.

Crawling to the finish line: why do endurance runners collapse? Implications for understanding of mechanisms underlying pacing and fatigue

Effective regulation of pace enables the majority of runners to complete competitive endurance events without mishap. However, some runners do experience exercise-induced collapse associated with postural hypotension, which in rare cases results from life-threatening conditions such as cardiac disorders, cerebral events, heat stroke and hyponatraemia. Despite the experience of either catastrophic system failure or extreme peripheral muscle fatigue, some runners persist in attempting to reach the finish line, and this often results in a sequence of dynamic changes in posture and gait that we have termed the 'Foster collapse positions'. The initial stage involves an unstable gait and the runner assumes the 'Early Foster' collapse position with hips slightly flexed and their head lowered. This unstable gait further degrades into a shuffle referred to as the 'Half Foster' collapse position characterized by hip flexion of approximately 90° with the trunk and head parallel to the ground. At this point, the muscles of postural support and the co-ordination of propulsion begin to be compromised. If the condition worsens, the runner will fall to the ground and assume the 'Full Foster' collapse position, which involves crawling forwards on knees and elbows towards the finish line, with their trunk angled such that the head is at a lower angle than the hips. Upon reaching the finish line, or sometimes before that, the runner may collapse and remain prone until recovering either with or without assistance or medical treatment. The Foster collapse positions are indicative of a final, likely primordial, protective mechanism designed to attenuate postural hypotension, cardiac 'pump' insufficiency or cerebral blood flow deficiency. Continuing to attempt to reach the finish line in this impaired state is also perhaps indicative of a high psychological drive or a variety of neurological and psychological pathologies such as diminished sensitivity to interoceptive feedback, unrealistic situational appraisal or extreme motivational drives. A better understanding of the physiological, neurological and psychological antecedents of the Foster collapse sequence remains an important issue with practical implications for runner safety and theoretical understanding of collapses during exercise.

Neural correlates of motor vigour and motor urgency during exercise

This article reviews the brain structures and neural circuitry underlying the motor system as it pertains to endurance exercise. Some obvious phenomena that occur during endurance racing events that need to be explained neurophysiologically are variable pacing strategies, the end spurt, motivation and the rating of perceived exertion. Understanding the above phenomena physiologically is problematic due to the sheer complexity of obtaining real-time brain measurements during exercise. In those rare instances where brain measurements have been made during exercise, the measurements have usually been limited to the sensory and motor cortices; or the exercise itself was limited to small muscle groups. Without discounting the crucial importance of the primary motor cortex in the execution of voluntary movement, it is surprising that very few exercise studies pay any attention to the complex and dynamic organization of motor action in relation to the subcortical nuclei, given that they are essential for the execution of normal movement patterns. In addition, the findings from laboratory-based exercise performance trials are hampered by the absence of objective measures of the motivational state of subjects. In this review we propose that some of the above phenomena may be explained by distinguishing between voluntary, vigorous and urgent motor behaviours during exercise, given that different CNS structures and neurotransmitters are involved in the execution of these different motor behaviours.

The influence of social evaluation on cerebral cortical activity and motor performance: a study of "Real-Life" competition

Motor performance in a social evaluative environment was examined in participants (N = 19) who completed a pistol shooting task under both performance-alone (PA) and competitive (C) conditions. Electroencephalographic (EEG), autonomic, and psychoendocrine activity were recorded in addition to kinematic measures of the aiming behavior. State anxiety, heart rate, and cortisol were modestly elevated during C and accompanied by relative desynchrony of high-alpha power, increased cortico-cortical communication between motor and non-motor regions, and degradation of the fluency of aiming trajectory, but maintenance of performance outcome (i.e., score). The findings reveal that performance in a complex social-evaluative environment characterized by competition results in elevated cortical activity beyond that essentially required for motor performance that translated as less efficient motor behavior.

Breaking away: effects of nonuniform pacing on power output and growth of rating of perceived exertion

The rating of perceived exertion (RPE) normally grows as a scalar function of relative competitive distance, suggesting that it may translate between the brain and body relative to managing fatigue during time-trial exercise. In nonstandard pacing situations, a reciprocal relationship between RPE and power output (PO) would be predicted.

PURPOSE

To determine whether PO would decrease when RPE was forced above the normal growth curve during a cycle time trial.

METHODS

Well-trained cyclists performed randomly ordered 10-km cycle time trials. In CONTROL they rode at their own best pace throughout. In BURST, they made a 1-km "burst" at the 4-km mark and then finished as rapidly as possible.

RESULTS

CONTROL was significantly (P < .05) faster than BURST (16:36 vs 17:00 min). During CONTROL, responses between 4 and 5 km were PO, 240 W; RPE, 5-6; and blood lactate [HLa], 8-9 mmol/L. During BURST PO increased to 282 W, then fell to 220 W after the burst and remained below CONTROL until the end spurt (9 km). RPE increased to 9 during the burst but returned to the normal RPE growth pattern by 6 km; [HLa] increased to ~13 mmol/L after the burst and remained elevated throughout the remainder of the trial.

CONCLUSIONS

The reciprocal behavior of RPE and PO after BURST supports the hypothesis that RPE translates between the brain and the body during heavy exercise. However, the continuing reduction of PO after the burst, even after RPE returned to its normal growth pattern, suggests that PO is regulated in a more complex manner than reflected solely by RPE.

How do humans control physiological strain during strenuous endurance exercise?

BACKGROUND

Distance running performance is a viable model of human locomotion.

METHODOLOGY/PRINCIPAL FINDINGS

To evaluate the physiologic strain during competitions ranging from 5-100 km, we evaluated heart rate (HR) records of competitive runners (n = 211). We found evidence that: 1) physiologic strain (% of maximum HR (%HRmax)) increased in proportional manner relative to distance completed, and was regulated by variations in running pace; 2) the %HRmax achieved decreased with relative distance; 3) slower runners had similar %HRmax response within a racing distance compared to faster runners, and despite differences in pace, the profile of %HRmax during a race was very similar in runners of differing ability; and 4) in cases where there was a discontinuity in the running performance, there was evidence that physiologic effort was maintained for some time even after the pace had decreased.

CONCLUSIONS/SIGNIFICANCE

The overall results suggest that athletes are actively regulating their relative physiologic strain during competition, although there is evidence of poor regulation in the case of competitive failures.

VO2max during successive maximal efforts

The concept of VO(2)max has been a defining paradigm in exercise physiology for >75 years. Within the last decade, this concept has been both challenged and defended. The purpose of this study was to test the concept of VO(2)max by comparing VO(2) during a second exercise bout following a preliminary maximal effort exercise bout. The study had two parts. In Study #1, physically active non-athletes performed incremental cycle exercise. After 1-min recovery, a second bout was performed at a higher power output. In Study #2, competitive runners performed incremental treadmill exercise and, after 3-min recovery, a second bout at a higher speed. In Study #1 the highest VO(2) (bout 1 vs. bout 2) was not significantly different (3.95 +/- 0.75 vs. 4.06 +/- 0.75 l min(-1)). Maximal heart rate was not different (179 +/- 14 vs. 180 +/- 13 bpm) although maximal V(E) was higher in the second bout (141 +/- 36 vs. 151 +/- 34 l min(-1)). In Study #2 the highest VO(2) (bout 1 vs. bout 2) was not significantly different (4.09 +/- 0.97 vs. 4.03 +/- 1.16 l min(-1)), nor was maximal heart rate (184 + 6 vs. 181 +/- 10 bpm) or maximal V(E) (126 +/- 29 vs. 126 +/- 34 l min(-1)). The results support the concept that the highest VO(2) during a maximal incremental exercise bout is unlikely to change during a subsequent exercise bout, despite higher muscular power output. As such, the results support the "classical" view of VO(2)max.