Cardiorespiratory Fitness Predicts Improvements In Phase Angle Among Cancer Survivors

INTRODUCTION: Phase angle (PhA) is a measurement of cell membrane integrity and has been recognized as a prognostic component of cancer survival, with a higher PhA indicating greater cellular health and increased survival in cancer patients. There is limited research indicating that exercise programs improve PhA, and the precise physiological variables contributing to that improvement are understudied. PURPOSE: To analyze the relationships between PhA and the major components of the exercise program, cardiorespiratory fitness (CRF) and muscular strength, in cancer survivors. METHODS: Seventy-three cancer survivors completed a 12-week, individualized exercise program. Subjects completed pre-to-post assessments of cardiorespiratory fitness (CRF), upper body (UB) and lower body (LB) muscular strength. Body composition and PhA were measured using InBody Bioelectrical Impedance Analyses. Simple and multiple linear regression were used to evaluate if CRF, UB, and LB were significant predictors of PhA. The relationships between PhA, CRF, UB, and LB were examined using Pearson correlation coefficients. RESULTS: PhA increased an average of 1.9% (p = 0.02) in participants following the 12-week intervention. Significant improvements occurred in CRF, UB and, LB, 12.4%, 10.6%, 13.6%, respectively (p < 0.001). CRF, UB, and LB explained 19.5% (r2 = 0.195) of the variance in PhA prior to subjects completing a 12-week intervention, however CRF was the only significant predictor of PhA (p = 0.039). Following the 12-week intervention significant improvements occurred in CRF, UB and, LB, 27%, 13.9%, 17.5%, respectively (p < 0.001). CRF, UB, and LB explained 27% (r2 = 0.27) of the variance in PhA. CRF was correlated 45.2% with PhA and remained its only significant predictor (p = 0.006). CONCLUSION: PhA significantly increased following a 12-week exercise program, attributed to the improvement of CRF. Cancer and its treatments cause known toxicities impairing cellular health and physical function. Although improvements in all components of the exercise program benefit PhA, CRF remains the most powerful predictor. This is likely due to its integrative effect on respiratory, cardiovascular, and musculoskeletal systems, emphasizing the necessity for aerobic exercise in exercise-based cancer rehabilitation.