Dynamics of pleasure-displeasure at the limit of exercise tolerance: conceptualizing the sense of exertional physical fatigue as an affective response

Abstract

The search for variables involved in the regulation and termination of exercise performance has led to integrative models that attribute a central role to the brain and utilize an array of psychological terms (e.g., sensation, perception, discomfort, tolerance). We propose that theorizing about exercise regulation would benefit by establishing crossdisciplinary bridges to research fields, such as affective psychology and neuroscience, in which changes along the dimension of pleasure-displeasure are considered the main channel via which homeostatic perturbations enter consciousness and dictate corrective action (slowing down or stopping). We hypothesized that ratings of pleasure-displeasure would respond to the severity of homeostatic perturbation and would be related to time-to-exhaustion during exercise performed at an unsustainable intensity. In a within-subjects experiment (N=15, 13 men and 2 women, age 23.4±2.2 y; peak oxygen uptake 46.0±8.0 ml·kg−1·min−1), we compared the slope of ratings of pleasure-displeasure (acquired every one min) during cycling exercise at a power output 10% above critical power until volitional termination under glycogen-loaded and glycogen-depleted conditions. As hypothesized, ratings of pleasure-displeasure declined more steeply under glycogen depletion (p=0.009, d=0.70) and correlated closely with time-to-exhaustion under both glycogen-loaded (r=0.85; p<.001) and glycogen-depleted conditions (r=0.83; p<.001). We conclude that in exercise, as in other domains, changes in pleasure-displeasure may be the main channel via which homeostatic perturbations enter consciousness. This proposal may have important implications for conceptualizing and identifying the neurobiological mechanisms of the sense of exertional physical fatigue.

Exercise slightly above the maximal lactate steady state reduces self-efficacy and increases negative affect

“…Ongoing challenges to homeostasis, even when compensable by homeostatic regulatory processes or at rest following exercise cessation, likely give rise to increased sensations of fatigue i.e., increased effort, and influence affective state 30 . The present results add to the theoretical 29,30 and experimental evidence 17,18 linking sensations of effort and affective exercise responses to interoceptive awareness of the physiological state.…”

“…Our data only provide partial support for these suggestions because whilst both self-efficacy and effort were associated with exercise tolerance after MLSS, only affective state was associated with subsequent exercise tolerance in both conditions. Hartman et al, (2018) 18 examined the association between affective states and TTE during exercise above the critical power, which is broadly equivalent to the MLSS. As here, they report strong associations between affective responses to exercise and exercise tolerance.…”

“…The perceptual consequences of sustained exercise, and subsequent exercise tolerance, are typically defined in terms of changes in effort/exertion (hereafter referred to as effort) and performance 2 , however others have argued that affective state may be a more important regulator of performance than perceived effort 16 . Prior performance of fatiguing exercise increases sensations of affect and effort, which are associated with subsequent exercise tolerance 17,18 . Although self-efficacy may be associated with exercise tolerance, further examination of the relationship between affective and perceptive responses to different exercise intensities, self-efficacy and exercise tolerance is needed.…”

Social Reward and Support Effects on Exercise Experiences and Performance: Evidence from Parkrun

“…These hypotheses are theoretically situated in a broad evolutionary approach to humans as thoroughly social creatures, for whom surviving and thriving depends on social connections [45][46][47]. In this view, the social environment directly in uences the brain-body signalling that undergirds adaptive homeostatic maintenance in everyday life, including in physical exercise, via affective states experienced as pleasure-displeasure [48][49][50][51]. Moreover, the intrinsic pleasure of social connection that is experienced in the context of close bonds is thought to arise in part via activation of endogenous neurobiological systems, such as the opioidergic and endocannabinoid systems [47,52,53], that are also involved in modulating responses to nociceptive stimuli and in sustaining endurance exercise [54][55][56][57].…”

Prolonged cognitive activity increases perception of fatigue but does not influence perception of effort, affective valence or performance during subsequent isometric endurance exercise.

“…Other psychological processes, including affective responses, have also been shown to be an important component of participant selfregulation during endurance performance, potentially involved in gating conscious awareness of other percepts (e.g. effort) and mediating action-based cognitive functions (Hartman et al, 2019;Venhorst et al, 2018). As far as we are aware, the affective responses evoked during endurance performance following the inducement of mental fatigue have not yet been investigated.…”