Abstract
INTRODUCTION: This study examined the impacts of different negative pressure cupping therapies (NPCT) on pain relief, functional recovery, and inflammatory regulation in delayed onset muscle soreness (DOMS) after high-intensity exercise, with the aim of clarifying the dose-effect relationship. METHODS: In this study, 55 healthy male participants aged 18-25 were selected and divided into 5 groups: the control group (CTR; n = 11) and NPCT groups at different levels (-25 kPa, -35 kPa, -45 kPa, and -55 kPa; n = 11 in each group). A high-intensity protocol, which included 6 sets of lunges, squats, and squat jumps, was adopted to induce DOMS in the quadriceps femoris. Immediately after the exercise, the DGN-6 vacuum device was used for a 10 min NPCT treatment. The research outcomes included visual analog scale (VAS) pain scores, lower extremity explosive strength tests (30-meter sprint and standing long jump), joint range of motion (ROM), and serum biomarkers [CK, LDH, and inflammatory cytokines (IL-6, TNF-α, and Hsp27)]. These were assessed at the baseline and 24 h after the intervention. RESULTS: NPCT groups exhibited significantly lower VAS scores than the CTR group (-55 kPa: 1.57 ± 0.79 vs. 6.14 ± 0.69; P < 0.05), and the efficacy was pressure-dependent (-55 kPa > -4 kPa > -35 kPa; P < 0.01). Functional recovery was significantly improved in NPCT groups (30-meter sprint: 0.27 s; standing long jump: 0.08 m; P < 0.01). Knee ROM increased by 5.71° at -55 kPa and 6.43° at -45 kPa (P < 0.05). Biochemically, CK/LDH levels normalized in -45 kPa and -55 kPa groups (P < 0.05). Meanwhile, the levels of IL-6 and TNF-α decreased significantly (P < 0.05), and these changes were correlated with Hsp27 expression (r = 0.42-0.49; P < 0.05). DISCUSSION: These findings demonstrate that NPCT at pressures ranging from -45 kPa to -55 kPa is most effective in alleviating DOMS by enhancing hemodynamics and modulating the anti-inflammatory response, which supports its integration into post-exercise rehabilitation protocols. CLINICAL TRIAL REGISTRATION: https://www.chictr.org.cn/showprojEN.html?proj=263241, Chinese Clinical Trial Registry (ChiCTR) (Registration NO.: ChiCTR- 2500098071, 03/03/2025).