Increase of circulating beta-endorphin-like immunoreactivity correlates with the change in feeling of pleasantness after running

Hormonal Responses to Exercise and Training: A Short Review

“…The release of opioids into plasma during exercise has been suggested to be the physiological basis of what runners recognize as the 'runner's high' (Appenzeller, 19811, or what others might consider 'addiction to running'; there is, however, little direct experimental evidence to confirm this concept. The change in plasma j-endorphin levels showed a statistical correlation with changes in feelings of 'pleasantness' in one study (Wildmann et al, 1986); another noted analgesia to a proportion of stimuli after a 6 mile run which was partially blocked by naloxone, as well as increases in psychometric parameters corresponding to 'joy' and 'euphoria' which were blocked by naloxone, and 'co-operation' and 'conscientiousness' which were not (Janal et al, 1984). In addition two groups have reported that infusion of naloxone during exercise results in an increase in the perceived effort of exercise (Surbey et al, 1983;Grossman et al, 1984); changes in central opioids may therefore be modulating the perception of the exercise stimulus.…”

Disentangling Fun and Enjoyment in Exergames Using an Expanded Design, Play, Experience Framework: A Narrative Review

“…10,32 Being physically active, exclusively, triggers a set of physiological responses, perhaps accounting for the enjoyment experience described when exercising. [33][34][35] Exercising places a demand on the cardiorespiratory system, which stimulates a release of catecholamines (dopamine, serotonin, norepinephrine, and acetylcholine), 36 resulting in increased heart rate, respiration, and cerebral blood flow. These neurotransmitters direct mood states and contribute to the experience of enjoyment.…”

Persistently Low Natural Killer Cell Activity and Circulating Levels of Plasma Beta Endorphin: Risk Factors for Infectious Disease

“…Of course, the changes we noted were small in comparison to those observed, for example, following the administration of potent pharmacologic agents (e.g., haloperidol [26]), or after strenuous exercise (27).…”