How Short Can It Be? The Effectivity of Intense Short Exercise in Reducing Pain Sensitivity

Background: Continuous aerobic exercise at about 70% of maximal aerobic capacity reduces pain sensitivity, even after a single session. We were the first to recently report the analgesic effects of intense aerobic interval exercise (85% heart rate reserve). The dependency of the induced analgesia on the intensity of the exercise may imply a potential analgesic effect of intense anaerobic exercise, which has not yet been studied.

Aim: To investigate the analgesic effect of a single bout of anaerobic exercise.

Methods: Fifty healthy subjects aged 24-33 years were randomly assigned to experimental (n=30) and control (n=20) groups. All subjects completed questionnaires assessing pain-related psychological factors. The experimental group performed the Wingate Anaerobic Test (WANT). Peak power, average power and fatigue percentage were recorded. Psychophysical pain tests performed before and after the interventions included heat and pressure pain thresholds measured locally (quadriceps) and in a remote area (thenar eminence), and pain ratings (numerical pain scale-NPS) were taken of suprathreshold tonic heat (46.5°C) and cold (10°C) stimuli applied in a remote area.

Results: Following WANT, heat (p=0.001) and pressure pain (p=0.004) thresholds increased and pain ratings in response to heat (p=0.001) and cold (p=0.001) stimuli decreased, compared to controls.

Conclusion: WANT induced local and remote analgesic effects implying involvement of central pain modulatory pathways in the analgesic effects of anaerobic exercise.