Acute effects of aerobic versus combined aerobic and cervical–upper extremity resistance exercise on pressure pain threshold, pain perception, and fatigue in workers exposed to high ergonomic risk with chronic non-specific neck pain: a randomized controlled trial

Workers exposed to high ergonomic risk often experience chronic non-specific neck pain (CNNP). Exercise-induced hypoalgesia (EIH) has been observed after various types of exercise, but the immediate effects of different exercise modalities in such individuals are unclear. This study aimed to compare the acute effects of aerobic exercise (AE) and combined exercise (CE) protocols on pressure pain threshold (PPT), pain perception, and fatigue in workers with high ergonomic risk and CNNP. In this randomized controlled trial with three parallel groups, 78 workers with high ergonomic risk (Rapid Upper Limb Assessment 4–7) and CNNP were allocated to an AE, CE, or control group (CG) ( n = 26 per group; age: 32.18 ± 9.79 years). AE involved 30 min of moderate-intensity recumbent cycling, while CE comprised 15 min of aerobic exercise followed by 15 min of cervical and upper-extremity elastic-band resisted exercises. The CG received 30 min of ergonomic and exercise education. PPT was assessed bilaterally at C2, C5, and the upper trapezius using a digital algometer, and neck pain, overall pain perception, and fatigue were evaluated using a numerical rating scale (NRS) before, immediately after, and 20 min post-exercise. Group × time interactions were analyzed using repeated-measures analysis of variance (ANOVA). Significant group × time interactions were found for PPT, pain,and fatigue ( p < 0.05). Post-hoc analysis indicated that AE resulted in greater increases in PPT ( p = 0.004– 0.046; partial etasquared ( η p 2 ) = 0.079–0.137). Neck-pain perception decreased in both the AE and CE groups compared to the CG ( p < 0.001; η p 2 = 0.223). CE showed reductions in overall pain and fatigue ( p = 0.007; η p 2 = 0.125; p = 0.022; η p 2 = 0.097). Both exercise groups improved over time ( p ≤ 0.013; η p 2 = 0.119–0.440). Both AE and CE were associated with acute EIH in workers with CNNP, but the response patterns differed between groups. While the AE group showed more consistent PPT responses, CE was associated with greater reductions in pain perception and fatigue. These findings suggest that brief workplace-compatible exercise strategies may have practical value for managing immediate symptoms in workers with CNNP. Future research should explore the longer-term effects of acute exercise in this population. Trial Registration: ClinicalTrials.gov (NCT 07546838), 2026-04-23, retrospectively registered.