An fMRI study on the acute effects of exercise on pain processing in trained athletes

Abstract

Endurance exercise is known to promote sustained antinociceptive effects, and there is evidence that the reduction of pain perception mediated by exercise is driven by central opioidergic neurotransmission. To directly investigate the involved brain areas and the underlying neural mechanisms in humans, thermal heat-pain challenges were applied to 20 athletes during 4 separate functional magnetic resonance imaging (fMRI) scans, i.e., before and after 2 hours of running (exercise condition) and walking (control condition), respectively. Imaging revealed a reproducible pattern of distributed pain-related activation in all 4 conditions, including the mesial and lateral pain systems, and the periaqueductal gray (PAG) as a key region of the descending antinociceptive pathway. At the behavioral level, running as compared with walking decreased affective pain ratings. The influence of exercise on pain-related activation was reflected in a significant time × treatment interaction in the PAG, along with similar trends in the pregenual anterior cingulate cortex and the middle insular cortex, where pain-induced activation levels were elevated after walking, but decreased or unchanged after running. Our findings indicate that enhanced reactive recruitment of endogenous antinociceptive mechanisms after aversive repeated pain exposure is attenuated by exercise. The fact that running, but not walking, reproducibly elevated β-endorphin levels in plasma indicates involvement of the opioidergic system in exercise. This may argue for an elevated opioidergic tone in the brain of athletes, mediating antinociceptive mechanisms. Our findings provide the first evidence using functional imaging to support the role of endurance exercise in pain modulation.

Does an aerobic endurance programme have an influence on information processing in migraineurs?

“…We can only speculate about possible mechanisms of exercise in migraine. On the one hand, the exercise may reduce the pain perception through activation of opioidergic system [52]. This could have been the case, because the exercise in our study influenced the migraine duration more than the frequency of migraine.…”

Effects of Intensive Diet and Exercise on Knee Joint Loads, Inflammation, and Clinical Outcomes Among Overweight and Obese Adults With Knee Osteoarthritis

“…The pain reduction in the E group, despite increased joint loads, inflammation, and walk speed, may indicate psycho-physiological effects of exercise on the central 34 and peripheral nervous systems. 35 …”

The type of sport matters: Pain perception of endurance athletes versus strength athletes

“…Studies have also shown that intense exercise is followed by an increase in heat-pain thresholds, a phenomenon termed "exercise induced analgesia" (EIA; Scheef et al, 2012;Koltyn, Brellenthin, Cook, Sehgal, & Hillard, 2014;Crombie, Brellenthin, Hillard, & Koltyn, 2017). Although EIA lasts up to 30 min (Hoffman et al, 2004), perhaps its effects are cumulative, namely the EIA of athletes is constantly on an "on" mode, whereas it has an "on" and "off" modes among non-athletes, depending on the frequency/intensity of their exercises.…”

“…Studies have shown the reinforcement of CPM during distraction (Defrin, Tsedek, Lugasi, Moriles, & Urca, 2010;Droste, Greenlee, Schreck, & Roskamm, 1991;Lautenbacher, Prager, & Rollman, 2007), a state reported frequently by endurance athletes, especially triathletes. Endurance athletes also report euphoria following training, which correlated with pain threshold and endogenous opioids increase (Boecker et al, 2008;Droste et al, 1991) as well as with brain activation in pain modulation regions (Boecker et al, 2008;Scheef et al, 2012). Thus, endurance athletes may have greater potential than strength athletes, for top-down pain modulation enhancement.…”