Neuromuscular Mechanisms Contributing to Self-Reported Post-Treatment Cancer Fatigue and the Effects of Resistance Training

Cancer fatigue is reported as the most frequent symptom experienced by disease-free, post-treatment cancer patients and is perceived to be more severe than both pain and nausea. The significance of cancer fatigue is that it interferes with usual functioning, limiting the ability to carrying out essential activities of daily living and reduces quality of life. Despite this, the underlying pathophysiological mechanisms involved remain largely unknown. This is probably because the development of cancer fatigue likely represents a complex interaction between various disease and treatment factors and patient susceptibility. As such, limited understanding of the mechanisms involved in cancer fatigue impairs our ability to develop objective diagnostic criteria and successful mechanistic-driven interventions for this symptom. One approach to enhance our understanding of the pathophysiological mechanisms associated with cancer fatigue is to examine the manifestations of this symptom using exercise-induced fatigue models. The benefit of this approach is that manifestations of cancer fatigue symptoms could be objectively examined using reliable assessment methodologies widely adopted in neuromuscular research. However, few studies have used an exercise-induced fatigue models to investigate cancer fatigue. As such, the principal aim of this PhD thesis is compare the central contributions to exercise-induced fatigue associated with a sustained maximal voluntary isometric contraction of the elbow flexors between disease-free cancer survivors with persistent fatigue symptoms and healthy participants. In addition, physical activity, such as resistance training has demonstrated some success as an intervention for reducing patient reported severity of cancer fatigue. However, the neuromuscular and physical capacity adaptations associated with improvements in reported fatigue symptoms within this clinical population are unknown. Therefore, a secondary purpose of this PhD thesis is to investigate the neuromuscular and physical capacity adaptations that occur following a 12-week progressive resistance training program.
The PhD studies outlined in this thesis have intended to address the gap within the literature by investigating the neuromuscular and physical capacity adaptations associated with the performance of a 2min sustained, maximal voluntary isometric contraction of the right elbow flexors and the systemic inflammation, self-reported fatigue, sleep quality, depressive symptoms, health-related quality of life, and measures of physical capacity changes following a 12 week progressive resistance training program between post-treatment cancer survivors and healthy women.