Exploring the Efficacy of Exercise Interventions To Improve Phase Angle

Abstract

Bioelectrical impedance analysis derived phase angle (PhA) has emerged as a non-invasive and easy-to-measure variable with significant implications. In clinical settings, PhA has shown associations with mortality, malnutrition, disease severity, and fitness. Individuals such as cancer survivors who undergo damaging treatments (i.e. chemotherapy and radiation therapy) present low PhA values. Since PhA is associated with levels of fitness in clinical populations, it was plausible that an exercise-based cancer rehabilitation program may improve PhA. However, no study prior to this work had shown a significant improvement in the PhA of cancer survivors. The foundational chapter in this dissertation was conducted to explore the relationships between health-related fitness components and PhA in breast cancer survivors. These findings indicate that PhA is more related to neuromuscular performance measures, such as muscular strength, rather than cardiovascular endurance-based performance. With this information, a concurrent exercise-based cancer rehabilitation program was designed that produced significant increases in the PhA breast cancer survivors. However, the efficacy of different training types on PhA remained unclear. Due to the multifactorial and detrimental effects of cancer treatments, it is unethical to ask cancer survivors to refrain from participating in exercise-based interventions that have been shown to mediate the aforementioned effects of treatment and improve quality of life. Therefore, the following chapters were conducted in a healthy population to explore the relationships between PhA and other measures of athletic performance and determine the effects of different training types (sprint interval training, resistance training, endurance training) on PhA. The novel findings of this dissertation inform practitioners of the relationships between PhA and athletic performance and provide valuable insights into longitudinal changes of PhA in response to different types of exercise interventions.