Physical exercise is increasingly recognized as an effective treatment for chronic pain. Studies in humans and animals have shown that a single session of exercise induces a reduction of sensitivity to experimental painful stimuli lasting up to 45 minutes. In a recent study conducted in our laboratory, we found (1) that this exercise- induced hypoalgesia (EIH) is mainly driven by local changes in muscle nociceptor sensitivity within exercising muscles and (2) that EIH is consistent at a group level but fluctuates across sessions within participants. The first aim of this project is to uncover the mechanism(s) that drive EIH by investigating whether processes that could contribute to an exercise-induced change in muscle nociceptor sensitivity match the fluctuating pattern of EIH. Specifically, we will assess the possible involvement in EIH of the endocannabinoid system (eCB), Kynurenic acid (KynA, a circulating myokine that transiently increases after exercise), and β -endorphins (βE). Using a sample of 90 healthy males and females aged 18 to 30 years, we will measure sensitivity to blunt pressure stimuli before, immediately after, and 45 min after a 25-min cycling exercise to assess muscle nociceptor sensitivity at exercising (rectus femoris muscle) and non-exercising (ventral forearm) muscles. Blood samples will be collected at these time-points to measure plasma levels of eCBs, βE, and KynA. In addition, the effect of sex on EIH is controversial: some studies report no differences between males and females, while others report a greater effect in males or in females. Therefore, a secondary aim of this study is to explore potential sex differences in the manifestation and underlying mechanism(s) of EIH.
Age range
18 Years – 30 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Pressure pain threshold
Timeframe: At each experimental experimental session (2 in total): before (T0), immediately after (T1), and 45 min (T2) after the intervention (cycling exercise).