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The Psychobiological Model of Endurance Performance: An Effort-Based Decision-Making Theory to Explain Self-Paced Endurance Performance

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Benjamin Pageaux at Université de Montréal
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LETTER TO THE EDITOR
The Psychobiological Model of Endurance Performance:
An Effort-Based Decision-Making Theory to Explain
Self-Paced Endurance Performance
Benjamin Pageaux
ÓSpringer International Publishing Switzerland 2014
To the Editor,
In a recent review published in this journal [1], Renfree and
colleagues demonstrated the importance of considering
decision-making theories to understand self-paced endur-
ance performance. The authors aimed to examine current
models/theories of decision-making in an attempt to
explain the manner in which regulation of muscular work
(pacing) is achieved during self-paced endurance perfor-
mance. As explained by the authors, it is crucial that
models explaining self-paced endurance performance take
into account both internal (e.g. perception of effort, phys-
iological responses) and external (e.g. tactical decisions,
presence of competitors) factors. Interestingly, among all
models presented in their review, the authors omitted to
present an effort-based decision-making model recently
proposed to explain self-paced endurance performance: the
psychobiological model (of endurance performance) [2].
The psychobiological model has been shown to provide a
valid explanation of the effects of both psychological [3,4]
and physiological [5] manipulations on endurance perfor-
mance during constant-load exercise (time to exhaustion).
Recently, its explanatory validity was extended to self-
paced exercise where endurance performance was altered
by psychological (mental fatigue) [6] and physiological
(muscle fatigue) [7] manipulations. Consequently, it seems
important to mention its existence in a review on decision-
making theories relevant to self-regulation of pacing.
Therefore, the main aim of this letter is to briefly present
the psychobiological model and its sensitivity to internal
and external factors known to alter self-paced endurance
performance. This letter will also attempt to provide to the
reader a brief alternative interpretation of the role of per-
ception of effort in endurance performance.
The psychobiological model is an effort-based decision-
making model [2] based on motivational intensity theory
[8], and postulates that the conscious regulation of pace is
determined primarily by five different cognitive/motiva-
tional factors:
1. Perception of effort
2. Potential motivation
3. Knowledge of the distance/time to cover
4. Knowledge of the distance/time remaining
5. Previous experience/memory of perception of effort
during exercise of varying intensity and duration
Factor 2 (potential motivation) refers to the maximum
effort an individual is willing to exert to satisfy a motive,
and could be easily influenced by external factors (e.g.
higher motivation during an event with competitors than
during laboratory testing). Factors 3 to 5 are self-explan-
atory and can explain the end-spurt phenomenon [9]or
why athletes start different races at different paces [10].
Perception of effort (factor 1) could be defined as ‘‘the
conscious sensation of how hard, heavy and strenuous a
physical task is’’ [2], and is the key determinant of this
model. Indeed, according to this model, the conscious
regulation of pace is primarily determined by the effort
perceived by the athlete. Therefore, when perception of
effort is increased by muscle [7] or mental [6] fatigue, or
reduced (same perception of effort for a higher power
output) by pharmacological manipulation [11], the athlete
will consciously change its pace to compensate for the
negative/positive effect of the experimental manipulation
B. Pageaux (&)
Endurance Research Group, School of Sport and Exercise
Sciences, University of Kent at Medway, Chatham Maritime,
Kent ME4 4AG, UK
e-mail: bp89@kent.ac.uk
123
Sports Med
DOI 10.1007/s40279-014-0198-2
Author's personal copy
on perception of effort, thus leading to an improvement (if
decreased perception of effort [11]) or impairment (if
increased perception of effort [6,7]) in self-paced endur-
ance performance. Because the five factors mentioned
above are sensitive to external and/or physiological factors
known to impact endurance performance, the psychobio-
logical model could be considered as a tool to explain
regulation of self-paced endurance performance.
Contrary to the models presented by Renfree and col-
leagues, the psychobiological model of endurance perfor-
mance postulates that the sensory signal processed by the
brain to generate perception of effort is not the afferent
feedback from skeletal muscles and other interoceptors
[12]. Perception of effort is thought to result from the
central processing of the corollary discharge associated
with the central motor command [12,13], thus explaining
the alteration of perception of effort and performance when
central motor command is increased to compensate for
muscle fatigue [7] or central processing of the corollary
discharge is altered by mental fatigue [3,6]. Despite this
theoretical difference in the underlying sensory signals
thought to generate perception of effort, the models pre-
sented by Renfree and colleagues and the psychobiological
model agree on the crucial role of perception of effort in
the self-regulation of pacing. Therefore, it is important to
understand the neurocognitive link between perception of
effort and the regulation of endurance performance during
self-paced exercise. Recently, a strong link between the
response inhibition process (a main component of decision-
making in human volition [14]) and perception of effort
was suggested [6]. In this study, subjects performed 30 min
of either incongruent (involving response inhibition) or
congruent (non involving response inhibition) Stroop task
followed by a five kilometres running time trial. Interest-
ingly, endurance performance following completion of the
incongruent Stroop task was decreased in association with
an increased perception of effort. One plausible explana-
tion provided by the authors is the similarity in brain areas
involved in both mechanisms. Indeed, perception of effort,
response inhibition and consequently decision-making
process are known to be associated with activity in the
anterior cingulate cortex and the pre supplementary motor
areas [3,4,6]. Therefore, independently of the model/
theory used to explain endurance performance, further
researches on the neurophysiology of perception of effort
are required to provide a better understanding of the reg-
ulation of endurance performance during self-paced
exercise.
Acknowledgments I would like to thank Romuald Lepers and
Samuele Marcora for our numerous discussions on this topic and their
feedback on this manuscript.
Conflict of interest The author has no potential conflicts of interest
that are directly relevant to the content of this letter.
References
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B. Pageaux
123
Author's personal copy
... As support for the corollary discharge model, it was demonstrated ) that increased central motor command resulting from previous exercise, without the incurrence of any metabolic fatigue, caused reductions in exercise performance with concomitant increases in RPE. The psychobiological model incorporates the corollary discharge model and ties in Brehm's motivational intensity theory (Brehm and Self 1989) and states that exercise performance is based on the conscious decision to continue exercise at a given pace based on the RPE (generated from corollary discharges), motivation, knowledge of distance or time remaining, and past experiences Pageaux 2014). Therefore, it has been suggested exercise tolerance and the generation of RPE may be either independent of feedforward anticipation or expectation and be a result of achieving the sensory tolerance limit, or a result of reaching the limit of corollary discharges where the effort required to maintain the task exceeds the subject's motivation to continue. ...
... Thus, these differences in pacing strategies may indicate that, as part of a more conservative pacing strategy, females considered the duration of exercise more so than males, thereby resulting in significant differences in power output when exercise was expected to last for 40-min compared to 20-min. Therefore, RPE-clamp exercise performance, based on either a theoretical central governor (Abbiss and Laursen 2005;Lambert et al. 2005;Millet 2011;Noakes 2011;St Clair Gibson et al. 2006) or a conscious decision-making process (Brehm and Self 1989;Edwards and Polman 2013;Marcora 2009;Pageaux 2014), may be more influenced by the expected duration of exercise in females than males. ...
... In describing the teleoanticipatory theory for pacing strategies and RPE, St. Clair Gibson (2006) presented evidence (Nikolopoulos et al. 2001) to support the claim that the brain's internal clock is robust to deception, however, the results of the current study demonstrate novel evidence that this internal clock is deceivable in females. While the results of the current study indicate the brain's internal clock may be more deceivable than previously thought (St Clair Gibson et al. 2006), these results may also provide evidence that RPE-clamp exercise performance is at least partially regulated by the expected duration of exercise as hypothesized in the pacing awareness model (Edwards and Polman 2013), flush model (Millet 2011), teleoanticipation algorithm (St Clair Gibson et al. 2006, perceptions-based model (Tucker 2009), complex systems model (Abbiss and Laursen 2005), psychobiological model Pageaux 2014) and central governor model (Noakes 2011). However, future studies are needed to examine the specific perceptions of time experienced during RPE-clamp trials when the expected duration of exercise is altered. ...
Influence of deception of task duration on the sex-specific physiological responses to RPE-clamp cycle ergometry
Article
Full-text available
  • Jan 2025
  • EUR J APPL PHYSIOL
Purpose The purpose of this study was to examine the sex-specific influence of expected exercise duration on the physiological responses to RPE-clamp exercise anchored to RPE 15 with participants being deceived into believing the RPE-clamp exercise would last for 20-, 30-, or 40-min, but all trials were 30-min. Methods Twelve males and 12 females completed a graded exercise test followed by randomly ordered RPE-clamp trials at RPE15 on the Borg 6–20 scale where subjects were deceived into expecting exercise to last for either 20-, 30-, or 40-min, but the actual duration for each trial was 30-min. Separate 2 (Sex [Male vs. Female]) × 3 (Deception [20-min, 30-min, 40-min]) × 11 (Time [0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 min]) mixed model analyses of variance (ANOVAs) with appropriate follow-up ANOVAs, and Bonferroni-corrected pairwise comparisons, were used to examine changes in volume of oxygen uptake (V˙O2\dot{V}O_{2}), heart rate (HR), respiration rate (RR), power output, and muscle oxygen saturation (%SmO2). Results Females, but not males, demonstrated lower power outputs when expected duration was 40-min compared to 20-min after approximately half of the exercise bout. V˙O2\dot{V}O_{2}, regardless of Sex, was also lower when expected duration was 40-min (62.47 ± 5.59% V˙O2max⁡\dot{V}O_{2\max }) compared to 20-min (66.35 ± 5.79% V˙O2max⁡\dot{V}O_{2\max }). There was no effect of expected duration on HR, RR, or %SmO2, but females demonstrated significantly higher HR (86.06 ± 5.93%HRmax) and RR (74.81 ± 7.26%RRmax) compared to males (79.52 ± 4.96%HRmax; 62.31 ± 5.80%RRmax). Conclusions RPE-clamp exercise performance in females, but not males, may be influenced by the expectation of exercise duration.
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... Ainsi, l'intensité ne peut être le seul facteur déterminant si un athlète puise dans ses réserves ou s'il récupère. D'autres facteurs, tels que l'état actuel des réserves de l'athlète, et le temps écoulé depuis le début de la séance, influent sans doute sur la capacité à récupérer et à poursuivre un exercice donné (Marcora 2019;Pageaux 2014). À cet effet, les modèles hydrauliques sont prometteurs, puisqu'ils proposent des causes multiples pour expliquer l'état d'épuisement d'un athlète (Sundström 2016;Eriksson, Holmberg, et Westerblad 2016;Noakes 2000). ...
... L'aspect psychologique joue un rôle majeur dans la performance sportive (Marcora 2019). Ainsi, un modèle complet de l'exercice continu ou intermittent devrait tenir compte, en plus des facteurs physiologiques, de facteurs psychobiologiques (Smirmaul, Dantas, et Nakamura 2013;Pageaux 2014;Marcora 2019;Fennell et Hopker 2021). Le niveau de motivation de l'athlète, le temps restant à la séance ou la fraction d'effort, la durée totale de la séance ou de la fraction d'effort, le niveau d'effort fourni depuis le début de la séance et les expériences passées de l'athlète sont des facteurs qui influent sans doute sur son aptitude à poursuivre à mesure que la séance progresse (Smirmaul, Dantas, et Nakamura 2013;Pageaux 2014;Marcora 2019). ...
... Ainsi, un modèle complet de l'exercice continu ou intermittent devrait tenir compte, en plus des facteurs physiologiques, de facteurs psychobiologiques (Smirmaul, Dantas, et Nakamura 2013;Pageaux 2014;Marcora 2019;Fennell et Hopker 2021). Le niveau de motivation de l'athlète, le temps restant à la séance ou la fraction d'effort, la durée totale de la séance ou de la fraction d'effort, le niveau d'effort fourni depuis le début de la séance et les expériences passées de l'athlète sont des facteurs qui influent sans doute sur son aptitude à poursuivre à mesure que la séance progresse (Smirmaul, Dantas, et Nakamura 2013;Pageaux 2014;Marcora 2019). Un modèle complet devra aussi tenir compte de variables contextuelles comme l'environnement (chaleur ou altitude), le bien-être psychologique de l'athlète, la quantité et la qualité de son sommeil, l'accumulation de fatigue des séances précédentes, etc. (Briand et al. 2022;Selye 1950;Stern, Hegedus, et Lai 2020;Leo, Giorgi, et al. 2022). ...
Appréciation des modèles courants de l’exercice intermittent
Thesis
Full-text available
  • May 2023
In many physical activities, exercise is not continuous, but intermittent: it involves a sequence of exercise fractions at varying intensities, some higher than others. In planned training, this type of exercise is found in the form of high intensity interval training (HIIT), which is an effective and time-efficient approach that has been popular in high-performance sports over the last century, and in clinical settings for the past twenty years. Models are available to predict performance during continuous exercise (without intensity variation) over various durations. The ecological validity of some continuous exercise models has been reported. However, this is not the case for intermittent exercise, which has several parameters that can be modified, leading to a large variation in individual responses. The purpose of this master’s thesis is to compare the major models of intermittent exercise and determine their strengths and weaknesses, the constructs on which they are based, and their applicability to various physical activities. The master’s thesis also reviews the evolution of continuous exercise models to better understand the elements that need to be considered to improve the validity of intermittent exercise modelling. Due to the lack of quality data to compare a set of HIIT sessions of the same degree of difficulty, the thesis presents a study that uses simulations to identify the main limitations of the intermittent exercise models included in commercial applications, i.e., the Coggan and Skiba models. The study reveals the limitations of these models in prescribing sessions with a low number of repetitions performed at supramaximal intensity, interspersed with long recovery periods. The main intermittent exercise models have limitations that restrict their widespread use. In order for intermittent exercise modelling to evolve into more valid models that improve understanding of the physiological phenomena involved, it is crucial that the models be tested against a robust set of comparable intermittent exercise data. The thesis draws a detailed portrait of the continuous and intermittent exercise models, accounts for their evolution over time, and provides elements to guide future exercise modelling. Finally, the thesis identifies the limits of the current intermittent exercise models, makes recommendations to sports practitioners to promote their good use, and proposes a modification to the Coggan model that reduces its limitations. Key words: modelling, critical power, anaerobic reserve, training load Dans plusieurs activités physiques, l’exercice n’est pas continu, mais intermittent : il comprend un enchaînement de fractions d’exercice à des intensités variées, certaines plus élevées que d’autres. Dans l’entraînement planifié, on retrouve ce type d’exercice sous la forme de l’entraînement par intervalles (EPI), qui est une approche efficace et économe en temps, très populaire dans les milieux sportifs depuis plus d’un siècle, et dans les milieux cliniques depuis plus d’une vingtaine d’années. Des modèles sont disponibles permettant de prédire les performances lors de l’exercice continu (sans variation d’intensité) sur des durées variées. La validité écologique de certains modèles de l’exercice continu a été rapportée, montrant leur capacité à s’appliquer aux situations observées sur le terrain. Ce n’est toutefois pas le cas pour l’exercice intermittent, qui comporte plusieurs paramètres pouvant être modifiés, et menant à une grande variation des réponses individuelles. L’objectif du mémoire est de comparer les principaux modèles de l’exercice intermittent et déterminer leurs forces et leurs faiblesses, les construits sur lesquels ils sont fondés, et leur applicabilité dans diverses activités physiques. Il s’agit aussi de revoir l’évolution des modèles de l’exercice continu pour mieux comprendre les éléments à considérer pour améliorer la validité de la modélisation de l’exercice intermittent. Face au manque de données de qualité permettant de comparer un ensemble de séances d’EPI de même degré de difficulté, le mémoire présente une étude qui procède par simulations pour identifier les principales limites des modèles de l’exercice intermittent inclus dans des applications commerciales, soit les modèles de Coggan et de Skiba. L’étude révèle les limites de ces modèles quant à la prescription de séances comprenant un faible nombre de répétitions effectuées à intensité supramaximale, entrecoupées de longues périodes de récupération. Les principaux modèles de l’exercice intermittent présentent des limites restreignant leur utilisation généralisée. Pour que la modélisation de l’exercice intermittent évolue vers des modèles plus valides, permettant d’améliorer la compréhension des phénomènes physiologiques en jeu, il est crucial de confronter les modèles à un ensemble robuste de données comparables de l’exercice intermittent. Le mémoire dresse un portrait détaillé des modèles de l’exercice continu et intermittent, fait état de leur évolution au fil du temps, et propose des éléments pour guider la suite des travaux de modélisation. Enfin, le mémoire identifie les limites des modèles de courants de l’exercice intermittent, présente des recommandations aux intervenants sportifs pour favoriser la bonne utilisation de ceux-ci, en plus de fournir une modification du modèle de Coggan qui diminue les limites de celui-ci. Mots-clés : modélisation, puissance critique, réserve anaérobie, charge d’entraînement
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... According to this model, task failure occurs (1) when the individual perceives the effort required to perform the task as equal to or beyond her/his motivation to succeed in the task, or (2) when the individual believes having exerted maximal effort so that exercise continuation is perceived as impossible or not worth it (Marcora et al. 2008;Marcora 2019). In this model, endurance performance is proposed to be influenced by two key factors: the motivation to succeed in the task and the perception of effort (Pageaux 2014;Marcora 2019). Specifically, any manipulation of the intensity of the perception of effort is supposed to alter endurance performance. ...
... To understand how the combination of physical training and motor imagery could improve endurance performance, we decided to use the framework of the psychobiological model of endurance performance (Marcora et al. 2008;Pageaux 2014). This model predicts that any intervention improving endurance performance should be associated with a reduction in the perception of effort reported by the participants. ...
Enhancing endurance performance with combined imagined and actual physical practice
Article
Full-text available
  • May 2024
  • EUR J APPL PHYSIOL
Purpose The perception of effort exerts influence in determining task failure during endurance performance. Training interventions blending physical and cognitive tasks yielded promising results in enhancing performance. Motor imagery can decrease the perception of effort. Whether combining motor imagery and physical training improves endurance remains to be understood, and this was the aim of this study. Methods Participants (24 ± 3 year) were assigned to a motor imagery (n = 16) or a control (n = 17) group. Both groups engaged in physical exercises targeting the knee extensors (i.e., wall squat, 12 training sessions, 14-days), with participants from the motor imagery group also performing motor imagery. Each participant visited the laboratory Pre and Post-training, during which we assessed endurance performance through a sustained submaximal isometric knee extension contraction until task failure, at either 20% or 40% of the maximal voluntary contraction peak torque. Perceptions of effort and muscle pain were measured during the exercise. Results We reported no changes in endurance performance for the control group. Endurance performance in the motor imagery group exhibited significant improvements when the intensity of the sustained isometric exercise closely matched that used in training. These enhancements were less pronounced when considering the higher exercise intensity. No reduction in perception of effort was observed in both groups. There was a noticeable decrease in muscle pain perception within the motor imagery group Post training. Conclusion Combining motor imagery and physical training may offer a promising avenue for enhancing endurance performance and managing pain in various contexts.
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... This phenomenon has been characterized as mental fatigue and has been shown to negatively impact physical performance (Schampheleer & Roelands, 2024). The proponents of this idea suggest that heightened mental fatigue contributes to an elevated perception of exertion during physical activity (Marcora et al., 2009;Pageaux, 2014) and this perception can impair exercise performance. Nevertheless, recent research has cast doubt on the robustness of this effect (Holgado et al., 2021;Holgado, Jolidon, et al., 2023). ...
Psychophysiological, subjective and physical responses to an individualized cognitive effort to failure
Preprint
Full-text available
  • Oct 2024
Over the past two decades, the interplay between cognitive tasks and physical performance has drawn increasing attention, with research suggesting that engaging in cognitive effort prior to exercise can impair subsequent physical performance due to heightened mental fatigue. However, recent studies have cast doubts on the robustness of this effect, prompting for a reassessment of the mechanisms underlying cognitive fatigue and its impact on physical performance. In this study, we present a novel approach aimed at addressing methodological limitations in prior research, with a focus on individualizing cognitive task difficulty and duration. By integrating innovative techniques such as Temporal Experience Tracing (TET) and psychophysiological monitoring, we sought to unravel the complex dynamics between cognitive engagement, subjective states, and physical performance. In a pre-registered (https://osf.io/8rkxq/), randomized, within-participant design experiment, 21 recreational athletes completed a running task to failure test at 90% of their maximal aerobic speed after performing a cognitive task until failure or watching a self-selected documentary (control). Six different subjective dimensions were recorded with the TET and pupillometry was recorded during cognitive task performance. The key findings of this study were: 1) subjective changes during effortful tasks are not limited to a single experience, such as mental fatigue or boredom, but can be grouped into distinct patterns; 2) despite the individualized and demanding cognitive tasks, completing them before exercise did not impair subsequent physical performance; 3) pupil size reliably reflected cognitive task performance until failure and partially reflected changes in subjective states, while fixation on the stimulus decreased over time, especially during high-demand periods. These results provide a new approach for understanding physical and behavioral responses, with implications for psychology and sports science. 3
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... Alkalosis influences afferents III and IV, which partially inhibit the respiratory centres of the central nervous system (Siegler et al. 2015). The "central governor" theory (Noaks et al. 2003), which was additionally extended by the effort-based decision-making theory (Pageaux 2014), is ultimately responsible for decisions on how the swimmer regulates swimming velocity. ...
The effects of sodium hydrogen carbonate ingestion during the recovery period between two 200-m front-crawl time trials
Article
Full-text available
  • Jun 2024
  • EUR J APPL PHYSIOL
Purpose The aim of this study was to determine how sodium hydrogen carbonate (NaHCO3) ingestion during a 1-h recovery period after a 200-m front-crawl swim affects blood–gas levels, acid–base balance, and performance during a successive trial. Methods Fourteen national-level male swimmers (age: 21 ± 3 years, body mass (BM):77 ± 10 kg, stature: 181 ± 7 cm) performed four maximal 200-m front-crawl tests. On one of the two days, the swimmers swam two 200-m tests with a 1-h recovery break, during which they drank water (WATER); on the other day, they performed the same protocol but consumed 0.3 g min⁻¹ NaHCO3 solution during the recovery break (NaHCO3). Results The ingestion of NaHCO3 before the second test had no effect on swim time despite a greater [HCO3-HCO3−{HCO}_{3}^{-}] (19.2 ± 2.3 mmol L⁻¹) than that measured during the first test (NaHCO3) (14.5 ± 1.1 mmol L⁻¹) and the other two tests (WATER) (12.7 ± 2.4 and 14.8 ± 1.5 mmol L⁻¹; F = 18.554; p = 0.000) and a higher blood pH (7.46 ± 0.03) than that measured during the first test (NaHCO3) (7.39 ± 0.02) and the other two tests (WATER) (7.16 ± 0.04 and 7.20 ± 0.05); (F = 5.255; p = 0.004). An increase in blood pCO2 (0.2 ± 0.3 kPa) between both tests (NaHCO3) compared to unchanged pCO2 values (− 0.1 ± 0.3 kPa) between the other two tests (WATER) (t = − 2.984; p = 0.011; power = 0.741) was confirmed. Conclusions NaHCO3 ingestion during the recovery period between two 200-m front-crawl time trials had a strong buffering effect that did not positively affect performance. An increase in pCO2 may have counterbalanced this impact.
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... S. Fortes, Lima-Junior, et al., 2021;Smith et al., 2017). Many theories regarding MF have been developed, such as the central governor theory (Inzlicht & Marcora, 2016), the psychobiological model (Pageaux, 2014), and the complex systems approach to exercise-induced tiredness (Lambert et al., 2005). These models suggest that fatigue arises due to interactions between central and afferent signals, followed by action and that systems-based methodologies analyse the system as a whole instead of concentrating solely on human behaviour . ...
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... These feelings of cognitive fatigue are known to impede engagement in physically active behaviours by influencing the intended willingness to exercise and exercise intensity, which in turn lowers the actual exercise performance [15,16]. However, current research has mostly examined the relationship between cognitive fatigue and vigorous-intensity physical activities, like running and cycling [12,15,[17][18][19]. Therefore, within this study we want to examine if cognitive fatigue is also a perceived barrier for moderate-intensity activities, specifically brisk walking. ...
Boosts for walking: how humorous messages increase brisk walking among cognitively fatigued individuals
Article
Full-text available
  • Jan 2024
  • BMC PUBLIC HEALTH
Background A well-studied internal barrier to regular physical activity, and more specifically brisk walking, is cognitive fatigue. However, thus far little research examined how cognitively fatigued individuals can be motivated to exercise, more specifically to engage in brisk walking. This study investigates whether humorous intervention messages might be an effective strategy to motivate cognitively fatigued individuals to brisk walk, and through which underlying processes. Methods An online experiment was performed in which variation in cognitive fatigue was induced through mental arithmetic questions. Afterwards, participants (n = 250) recruited through Prolific, randomly received either humorous or non-humorous intervention messages related to brisk walking. Potential mediators of the relations between physical activity, humour and cognitive fatigue were measured, were self-efficacy, self-control, and motivation. Results First, regression analyses confirmed that cognitive fatigue negatively influences brisk walking intentions and that the perceived humour of the intervention messages moderated this relationship. Second, results showed that self-control and self-efficacy are mediators explaining the relationship between cognitive fatigue and brisk walking intentions. Lastly, this study found that perceived humour of the intervention messages moderated the relationship between cognitive fatigue and self-control, indicating that perceptions of self-control were positively changed after receiving messages that were perceived as humorous compared to messages that were not perceived as humorous, subsequently increasing brisk walking intentions. Conclusions This study is the first to unravel the underlying relationship between humorous intervention messages and brisk walking intentions through positive changes in perceptions of self-control within a cognitively fatigued sample. Results of this study suggest that existing smartphone applications monitoring and promoting brisk walking should integrate tailored message strategies within their cues to brisk walk by implementing humour as a strategy to motivate users when they are cognitively fatigued.
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Neural mechanisms underlying the effects of cognitive fatigue on physical effort-based choice
Article
Full-text available
  • Dec 2024
Fatigue is a state of exhaustion that influences our willingness to engage in effortful tasks. While both physical and cognitive exertion can cause fatigue, there is a limited understanding of how fatigue in one exertion domain (e.g., cognitive) affects decisions to exert in another (e.g., physical). We use functional magnetic resonance imaging (fMRI) to measure brain activity while human participants make decisions to exert prospective physical effort before and after engaging in a cognitively fatiguing working memory task. Using computational modeling of choice behavior, we show that fatiguing cognitive exertion increases participants’ subjective costs of physical effort compared to a baseline rested state. We describe how signals related to fatiguing cognitive exertion in the dorsolateral prefrontal cortex influence physical effort value computations instantiated by the insula, thereby increasing an individual’s subjective valuation of prospective physical effort while cognitively fatigued. Our results support the idea of a general fatigue signal that integrates exertion-specific information to guide effort-based choice.
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Effects of prolonged engagement in alternating video games and smartphone use on muscle endurance and physical activity intentions in young healthy adults [PREPRINT]
Preprint
Full-text available
  • Nov 2024
Recent studies suggest a negative effect of acute smartphone use or video games on decision-making, psychomotor and maximal force production performances. This study aimed to test the effect of alternating video games and smartphone scrolling on social networks on subsequent muscle endurance performance and physical activity intention in young adults.Thirty-eight young adults (13 female; 19±1 y.o.) participated in this study. Participants engaged either in 90 minutes, alternating between video gaming and scrolling on smartphone (VGSS - experimental condition) or watching documentaries (control condition). Participants rated the perceived workload of each task and their mental fatigue, motivation and boredom during the VGSS or documentary watching. Cognitive performance and physical activity intention were measured pre-post VGSS and documentary watching. Then, participants performed a knee extensors endurance task until exhaustion at 20% of their maximal voluntary peak force, to measure muscle endurance performance. Participants perceived the VGSS as more demanding than the documentary condition. However, only a slight increase in perceived mental fatigue was highlighted and no difference between conditions in cognitive performance was observed. Muscle endurance performance did not differ after VGSS or documentary and physical activity intention decreased regardless of the condition.Engaging in VGSS did not induce a specific state of mental fatigue, thus explaining the absence of impaired muscle endurance performance, compared to watching a documentary. A negative impact on physical activity intentions was observed following both VGSS and documentary watching, suggesting that simply sitting in front of a screen impairs intentions to be active.
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Trunk variability and local dynamic stability during gait after generalized fatigue induced by incremental exercise test in young women in different phases of the menstrual cycle
Article
Full-text available
  • Oct 2023
Purpose The purpose of this study was to identify how generalized fatigue along with hormonal changes throughout the menstrual cycle affects trunk variability and local dynamic stability during gait. Methods General fatigue was induced by an incremental test on a treadmill, and the menstrual cycle was divided into three phases: follicular, ovulatory, and luteal. Twenty-six healthy, young volunteers (aged 18 to 28 years) who did not use oral contraceptives or other hormonal drugs with a regular menstrual cycle participated in the study. They walked on the treadmill for 4 min at the preferred speed, before the incremental test, followed by four sets of 4 min alternating between walking, also at preferred speed, and resting. From trunk kinematic data, the following were extracted: the mean of the standard deviation along strides, as a measure of variability, and the maximum Lyapunov exponent, as a measure of local dynamic stability (LDS). Results After the incremental test, variability increased, and LDS decreased. However, they showed a tendency to return to the initial value faster in women compared to previous results for men. In the follicular phase, which has less hormonal release, the volunteers had an almost complete recovery in LDS soon after the first rest interval, suggesting that female hormones can interfere with fatigue recovery. Nevertheless, concerning the LDS, it was significantly lower in the luteal phase than in the follicular phase. Conclusion Women that are not taking oral contraceptives should be aware that they are susceptible to increased gait instabilities in the pre-menstrual phase after strenuous activities.
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Response inhibition impairs subsequent self-paced endurance performance
Article
Full-text available
  • Feb 2014
  • EUR J APPL PHYSIOL
The aim of this study was to test the effects of mental exertion involving response inhibition on pacing and endurance performance during a subsequent 5-km running time trial. After familiarization, 12 physically active subjects performed the time trial on a treadmill after two different cognitive tasks: (i) an incongruent Stroop task involving response inhibition (inhibition task) and (ii) a congruent Stroop task not involving response inhibition (control task). Both cognitive tasks were performed for 30 min. Neither the inhibition nor the control task induced subjective feelings of mental fatigue. Nevertheless, time trial performance was impaired following the inhibition task (24.4 ± 4.9 min) compared to the control task (23.1 ± 3.8 min) because of a significant reduction in average running speed chosen by the subject. The response inhibition task did not affect pacing strategy, which was negative in both conditions. Heart rate and blood lactate responses to the time trial were not affected by the inhibition task, but subjects rated perceived exertion higher compared to the control condition (13.5 ± 1.3 vs 12.4 ± 1.3). These findings show for the first time that 30 min of mental exertion involving response inhibition reduces subsequent self-paced endurance performance despite no overt mental fatigue. The impairment in endurance performance observed after the incongruent Stroop task seems to be mediated by the higher perception of effort as predicted by the psychobiological model of endurance performance.
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Effects of isolated locomotor muscle fatigue on pacing and time trial performance
Article
Full-text available
  • Jun 2013
  • EUR J APPL PHYSIOL
Purpose: Locomotor muscle fatigue impairs exercise performance during time to exhaustion tests. However, its effect on self-regulation of power output (pacing) is unknown. The primary aim of this study was to investigate the effects of locomotor muscle fatigue on pacing and time trial performance. Methods: Ten healthy recreationally active men completed a 15-min time trial on a cycle ergometer 30 min after undergoing an eccentric fatiguing protocol designed to induce a substantial strength loss in the knee extensor muscles without inducing significant metabolic stress. This fatigue condition was compared with a control condition, using a randomly counterbalanced AB/BA crossover design. Results: Total work completed during the 15-min cycling time trial was significantly reduced by 4.8 % in the fatigue condition compared with the control condition. This was caused by a significant reduction in power output. Rating of perceived exertion was significantly higher in the fatigue condition compared with the control condition only during the first 3 min of the time trial. Heart rate and vastus lateralis integrated electromyogram were not significantly different between the two conditions. Conclusion: The results show that participants with fatigued locomotor muscles reduce their pace but do not change their pacing strategy. As a result, there was a significant reduction in time trial performance. As predicted by the psychobiological model of exercise performance, a slower pace may be a behavioral response to compensate for the significant increase in perception of effort induced by locomotor muscle fatigue.
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Prolonged Mental Exertion Does Not Alter Neuromuscular Function of the Knee Extensors
Article
Full-text available
  • May 2013
  • MED SCI SPORT EXER
Purpose: The aim of this study was to test the hypotheses that prolonged mental exertion (i) reduces maximal muscle activation and (ii) increases the extent of central fatigue induced by subsequent endurance exercise. Methods: The neuromuscular function of the knee extensor muscles was assessed in 10 male subjects in two different conditions: (i) before and after prolonged mental exertion leading to mental fatigue and (ii) before and after an easy cognitive task (control). Both cognitive tasks lasted 90 min and were followed by submaximal isometric knee extensor exercise until exhaustion (endurance task), and a third assessment of neuromuscular function. Results: Time to exhaustion was 13% ± 4% shorter in the mental fatigue condition (230 ± 22 s) compared with the control condition (266 ± 26 s) (P < 0.01). Prolonged mental exertion did not have any significant effect on maximal voluntary contraction torque, voluntary activation level, and peripheral parameters of neuromuscular function. A similar significant decrease in maximal voluntary contraction torque (mental fatigue condition: -26.7% ± 5.7%; control condition: -27.6% ± 3.3%, P < 0.001), voluntary activation level (mental fatigue: -10.6% ± 4.3%; control condition: -11.2% ± 5.2%, P < 0.05), and peripheral parameters of neuromuscular function occurred in both conditions after the endurance task. However, mentally fatigued subjects rated perceived exertion significantly higher during the endurance task compared with the control condition (P < 0.05). Conclusions: These findings provide the first experimental evidence that prolonged mental exertion (i) does not reduce maximal muscle activation and (ii) does not increase the extent of central fatigue induced by subsequent endurance exercise. The negative effect of mental fatigue on endurance performance seems to be mediated by the higher perception of effort rather than impaired neuromuscular function.
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Counterpoint: Afferent Feedback From Fatigued Locomotor Muscles Is Not An Important Determinant Of Endurance Exercise Performance
Article
Full-text available
  • Feb 2010
  • J APPL PHYSIOL
Since Noakes' controversial lecture on the central governor ([23][1]), brain regulation of endurance performance has been a hot topic in exercise physiology. In this series, Dr. Markus Amann argues that afferent feedback related to peripheral locomotor muscle fatigue is an important determinant of
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Mental fatigue impairs physical performance in humans
Article
Full-text available
  • Feb 2009
Mental fatigue is a psychobiological state caused by prolonged periods of demanding cognitive activity. Although the impact of mental fatigue on cognitive and skilled performance is well known, its effect on physical performance has not been thoroughly investigated. In this randomized crossover study, 16 subjects cycled to exhaustion at 80% of their peak power output after 90 min of a demanding cognitive task (mental fatigue) or 90 min of watching emotionally neutral documentaries (control). After experimental treatment, a mood questionnaire revealed a state of mental fatigue (P = 0.005) that significantly reduced time to exhaustion (640 +/- 316 s) compared with the control condition (754 +/- 339 s) (P = 0.003). This negative effect was not mediated by cardiorespiratory and musculoenergetic factors as physiological responses to intense exercise remained largely unaffected. Self-reported success and intrinsic motivation related to the physical task were also unaffected by prior cognitive activity. However, mentally fatigued subjects rated perception of effort during exercise to be significantly higher compared with the control condition (P = 0.007). As ratings of perceived exertion increased similarly over time in both conditions (P < 0.001), mentally fatigued subjects reached their maximal level of perceived exertion and disengaged from the physical task earlier than in the control condition. In conclusion, our study provides experimental evidence that mental fatigue limits exercise tolerance in humans through higher perception of effort rather than cardiorespiratory and musculoenergetic mechanisms. Future research in this area should investigate the common neurocognitive resources shared by physical and mental activity.
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Application of Decision-Making Theory to the Regulation of Muscular Work Rate during Self-Paced Competitive Endurance Activity
Article
  • Oct 2013
  • SPORTS MED
Successful participation in competitive endurance activities requires continual regulation of muscular work rate in order to maximise physiological performance capacities, meaning that individuals must make numerous decisions with regards to the muscular work rate selected at any point in time. Decisions relating to the setting of appropriate goals and the overall strategic approach to be utilised are made prior to the commencement of an event, whereas tactical decisions are made during the event itself. This review examines current theories of decision-making in an attempt to explain the manner in which regulation of muscular work is achieved during athletic activity. We describe rational and heuristic theories, and relate these to current models of regulatory processes during self-paced exercise in an attempt to explain observations made in both laboratory and competitive environments. Additionally, we use rational and heuristic theories in an attempt to explain the influence of the presence of direct competitors on the quality of the decisions made during these activities. We hypothesise that although both rational and heuristic models can plausibly explain many observed behaviours in competitive endurance activities, the complexity of the environment in which such activities occur would imply that effective rational decision-making is unlikely. However, at present, many proposed models of the regulatory process share similarities with rational models. We suggest enhanced understanding of the decision-making process during self-paced activities is crucial in order to improve the ability to understand regulation of performance and performance outcomes during athletic activity.
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Perception of effort reflects central motor command during movement execution
Article
  • Jun 2012
  • PSYCHOPHYSIOLOGY
It is thought that perception of effort during physical tasks is the conscious awareness of the central motor command sent to the active muscles. The aim of this study was to directly test this hypothesis by experimentally varying perception of effort and measuring movement-related cortical potential (MRCP). Sixteen healthy, recreationally active men made unilateral dynamic elbow flexions to lift a light (20% one repetition maximum, 1RM) and a heavier (35% 1RM) weight with a fatigued arm and a nonfatigued arm while rating of perceived effort (RPE), biceps brachii electromyogram (EMG), and MRCP were recorded. RPE, EMG amplitude, and MRCP amplitude at Cz during weight raising increased with weight and with muscle fatigue. There was a significant correlation between RPE and MRCP amplitude at the vertex during the weight raising epoch. This study provides direct neurophysiological evidence that perception of effort correlates with central motor command during movement execution.
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Human Volition: Towards a Neuroscience of Will
Article
  • Jan 2009
The capacity for voluntary action is seen as essential to human nature. Yet neuroscience and behaviourist psychology have traditionally dismissed the topic as unscientific, perhaps because the mechanisms that cause actions have long been unclear. However, new research has identified networks of brain areas, including the pre-supplementary motor area, the anterior prefrontal cortex and the parietal cortex, that underlie voluntary action. These areas generate information for forthcoming actions, and also cause the distinctive conscious experience of intending to act and then controlling one's own actions. Volition consists of a series of decisions regarding whether to act, what action to perform and when to perform it. Neuroscientific accounts of voluntary action may inform debates about the nature of individual responsibility.
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