Synergistic benefits of phytoncide exposure and resistance exercise on muscle health, QoL, and immuno-myokine regulation in ovarian cancer survivors: A randomized controlled trial

Background Although phytoncide exposure and resistance exercise are individually recognized for their beneficial effects on physiological parameters and immune-cell function in ovarian cancer survivors (OCS), this study aimed to investigate whether the integration of these two interventions could elicit synergistic improvements in myokine profiles, immunological responses, and muscle function, ultimately enhancing the quality of life (QoL) in OCS. Methods Participants aged 42 to 61 years were randomly selected from four hospital-based centers affiliated with a single medical institution. Those from one center were assigned to control group (CON, n  = 18), while individuals from the other three centers were allocated to phytoncide group (PHYT, n  = 19), exercise group (EXE, n  = 19), and phytoncide plus exercise group (PHYT + EXE, n  = 20), respectively. Each intervention was conducted for 60 min, 3 days per week, over a 12-week intervention. Result Relative to baseline, both muscle strength and endurance declined in the CON and PHYT after the intervention, whereas the EXE and PHYT + EXE showed improvements in these outcomes, demonstrating a significant interaction effect ( P  = 0.001). For the QoL domains, mobility ( P  = 0.008), self-care ( P  = 0.023), pain/discomfort ( P  = 0.001), and anxiety/depression ( P  = 0.046) scores increased in the CON, indicating worsening conditions, while these scores decreased across the other three groups, reflecting improving conditions. Interleukin (IL)-6 increased in CON, whereas they decreased in PHYT, EXE, and PHYT + EXE. In contrast, IL-10 exhibited an opposite trend to IL-6 ( P  = 0.001). Neutrophils ( P  = 0.002), lymphocytes ( P  = 0.001), monocytes ( P  = 0.005), and eosinophils ( P  = 0.016) decreased in CON, whereas those increased in PHYT, EXE, and PHYT + EXE, indicating significant interaction effects. Notably, PHYT + EXE demonstrated the greatest improvements in NK cells, CD3⁺, CD4⁺, and CD8⁺T cells and CD19⁺ B cells. Conclusions These findings indicate that the combination of phytoncide inhalation and resistance exercise improves muscle health and quality of life, and this effect appears to be mediated by enhancements in myokines and immune cell function in OCS. These multimodal approaches may serve as effective adjunct strategies for post-treatment rehabilitation. Trial registration This study was registered with the Clinical Research Information Service of the Korea Centers for Disease Control and Prevention under Clinical Trials KCT0008283 on 10/03/2023.