This randomized controlled trial tested whether offset analgesia (OffA)—a transient reduction in perceived pain after a small decrease in noxious stimulus intensity—can be translated from thermal testing into an exercise task. The primary objective was to determine if OffA applied during isometric exercise reduces pain and improves feelings toward exercise (affective valence) in young healthy adults.
Forty-nine young healthy adults participated in two research sessions, each including one of two randomized exercise tasks: a control task and an offset task. The sample comprised 24 women (mean age 21.8 ± 2.0 years) and 25 men (mean age 23.4 ± 5.7 years). The study design included both thermal and exercise OffA assessments using individualized stimulus intensities. The trial was approved by the Marquette University Institutional Review Board (IRB #4434).
For the thermal OffA assessment, noxious heat was applied to the forearm at an individualized test temperature that produced moderate pain (defined as the T1 time point). The stimulus was increased by 1 °C for 10 seconds (T2) and then returned to the original test temperature for 10 seconds (T3). A control thermal task was also conducted in which the noxious stimulus intensity remained constant across T1–T3. Pain ratings were collected at T1, T2, and T3.
The exercise OffA task used an isometric knee extension held by the participant’s right leg. The protocol began at 25% of maximal voluntary contraction (MVC) and was maintained until participants reported moderate pain (T1). Intensity was then increased to 50% MVC for 10 seconds (T2) and subsequently returned to 25% MVC for 10 seconds (T3). A matched control exercise condition held the intensity constant across time points. Pain was recorded at T1, T2, and T3. Affective valence (feelings toward the exercise) was measured during the exercise sessions.
Primary outcomes were pain ratings at the three time points (T1, T2, T3) for both thermal and exercise protocols. For exercise tasks only, affective valence was reported to assess the participant’s emotional response to the exercise under offset versus control conditions. The thermal OffA manipulated temperature by +1 °C at T2; the exercise OffA manipulated intensity between 25% and 50% MVC.
Both thermal and exercise tasks produced the expected OffA effect. Pain increased when the noxious stimulus was raised at T2 (temperature +1 °C or increased MVC) and then fell significantly when the stimulus returned to the original level at T3. The return to baseline stimulus generated a clinically meaningful reduction in perceived pain regardless of stimulus modality (painful heat or exercise). The findings indicate that the transient pain inhibition characteristic of OffA can occur during an isometric exercise paradigm.
Participants reported more positive affective valence at the end of exercise when performing the offset task compared with the control task. This difference was statistically significant (p < 0.001), indicating that applying the OffA pattern to exercise not only reduced pain but also improved subjective feelings toward the exercise bout.
The study demonstrates that OffA can be translated into an exercise prescription context: delivering a brief increase in intensity followed by a return to baseline produced a marked reduction in perceived pain and improved affective response during isometric knee extension in young healthy adults. These results suggest a practical approach to reduce exercise-related pain and enhance the emotional experience of exercise, which may have implications for adherence and rehabilitation. The abstract does not report longer-term outcomes, effects in clinical or older populations, or physiological mechanisms underlying the observed analgesia.
The randomized controlled trial was approved by Marquette University Institutional Review Board (IRB #4434). The abstract lists key trial identifiers including PMID 42631377 and DOI 10.1515/sjpain-2026-0022. Additional methodological details, trial registration, and extended outcome data were not reported in the abstract.