Phase angle is associated with muscle endurance and estimated maximum oxygen uptake in healthy young males

Purpose This study aimed to clarify the utility of Phase Angle by examining its relationship with muscle endurance and whole-body endurance in healthy young Japanese males. Participants and Methods This cross-sectional exploratory study included 24 healthy young male participants, aged 19.1 ± 0.3 years. Body composition by Bioelectrical impedance analysis, including whole body Phase Angle, was measured. To assess the muscle endurance of the quadriceps femoris and hamstrings, participants performed a test using an isokinetic dynamometer. The angular velocity was set at 180°/sec, a standard velocity used in endurance assessments. Oxygen uptake and heart rate were measured during a multistage continuous treadmill test, and maximum oxygen uptake was estimated by calculating a linear regression equation based on the relationship between heart rate and oxygen uptake. Pearson’s product-moment correlation analysis was performed to examine associations between Phase Angle, maximum oxygen uptake, and isokinetic measurement variables. Results Only Phase Angle showed significant correlations with extension 180°/sec maximum peak torque/body mass (%), muscle fatigue, and maximum oxygen uptake. Conclusion These results suggest that Phase Angle can be identified as a potential marker associated with muscle and whole-body endurance in young, healthy Japanese men. Phase Angle measurements may offer valuable insights for assessing physical condition in this population.