Beneficial Effects of Regular Physical Activity on Exercise-Induced Analgesia in Adolescent Males

Can we improve exercise-induced hypoalgesia with exercise training? An overview and suggestions for future studies

Exercise-induced hypoalgesia refers to a reduction in pain sensitivity following a single bout of exercise, which has been shown to be diminished or impaired with aging and chronic pain. Exercise training (repeated bouts of exercise over time) is often recommended as a non-pharmacological treatment for chronic pain and age-related functional declines. However, whether exercise training can augment the exercise-induced hypoalgesia has not been well studied. The purpose of this paper is to 1) provide an overview of the existing literature investigating the effect of exercise training on the magnitude of exercise-induced hypoalgesia, and 2) discuss potential underlying mechanisms as well as considerations for future research. Given the paucity of randomized controlled trials in this area, the effects of exercise training on exercise-induced hypoalgesia are still unclear. Several potential mechanisms have been proposed to explain the impaired exercise-induced hypoalgesia in chronic pain and older individuals (e.g., endogenous opioid, cardiovascular, and immune system). Exercise training appears to induce physiological changes in those systems, however, further investigations are necessary to test whether this will lead to improved exercise-induced hypoalgesia. Future research should consider including a time- and age-matched non-training group and utilizing the same exercise protocol for testing exercise-induced hypoalgesia across intervention groups.

Heart rate variability after vigorous physical exercise is positively related to loss aversion

BACKGROUND AND OBJECTIVES OF THE ARTICLE

Loss aversion bias, whereby losses loom larger than gains, can be reduced by stress. At the same time, vigorous physical exercise is a powerful neuroendocrine stressor and heart rate variability (HRV) provides an objective measure of the actual exercise impact, relative to each individual physical condition. Our aim was to study whether vigorous exercise can influence loss aversion, considering HRV in this relation. We hypothesized that the lower HRV derived from vigorous exercise (i.e., when stressor produced the most impact) would predict a lower loss aversion.

METHODS

Two groups (Experimental, N = 37; Control, N = 39) completed a loss aversion task, but the experimental group was exposed to an acute physical stressor before.

RESULTS

Results revealed a significant group x HRV interaction. In the control group, HRV was not associated with loss aversion. Conversely, as hypothesized, the lower HRV levels derived from exercise were associated with a lesser loss aversion in the experimental group.

CONCLUSIONS

Results suggest that physiological changes from physical exercise could affect decision-making by reducing loss aversion.

Exercise-induced hypoalgesia after acute and regular exercise: experimental and clinical manifestations and possible mechanisms in individuals with and without pain

This review describes methodology used in the assessment of the manifestations of exercise-induced hypoalgesia in humans and previous findings in individuals with and without pain. Possible mechanisms and future directions are discussed.

Exercise and physical activity is recommended treatment for a wide range of chronic pain conditions. In addition to several well-documented effects on physical and mental health, 8 to 12 weeks of exercise therapy can induce clinically relevant reductions in pain. However, exercise can also induce hypoalgesia after as little as 1 session, which is commonly referred to as exercise-induced hypoalgesia (EIH). In this review, we give a brief introduction to the methodology used in the assessment of EIH in humans followed by an overview of the findings from previous experimental studies investigating the pain response after acute and regular exercise in pain-free individuals and in individuals with different chronic pain conditions. Finally, we discuss potential mechanisms underlying the change in pain after exercise in pain-free individuals and in individuals with different chronic pain conditions, and how this may have implications for clinical exercise prescription as well as for future studies on EIH.