This application aims to expand non-pharmacologic options for the control of symptoms during chemotherapy using yoga practices. It is particularly focused on sleep disturbance with a secondary focus on fatigue. Sleep disturbance is among the most common symptoms experienced by cancer patients, occurs in up to 80% of patients during chemotherapy, and results in serious impairments in quality of life. Although pharmacologic therapies improve sleep disturbance, they have numerous side effects, problems with tolerance and dependence, and are not well studied in oncology patients. While non-pharmacologic therapies may decrease sleep disturbance, the current level of evidence on their efficacy is insufficient. Fatigue occurs in up to 95% of those receiving chemotherapy, and results in major impairments in functioning and quality of life. Despite its significance, few effective treatments currently exist for fatigue. Prior studies suggest that yoga may be helpful for sleep disturbance and fatigue, but these studies have limitations. An important challenge in yoga research is that it is typically a multi-modality practice that can include physical postures, breathing practices, and/or meditation components. Prior studies have not adequately addressed the effects of individual components. Therefore, key questions remain unanswered about the most effective elements of yoga; how to best combine them for particular problems such as chemotherapy symptoms; and optimal dosing. The current study will address these gaps in the literature and perform key developmental steps to prepare for a large randomized, controlled trial (RCT). It builds on preliminary work in which we have studied yoga breathing practices for chemotherapy symptoms and found initial evidence that it improved sleep disturbance, showed trends toward improvements in fatigue, and was feasible to implement in patients undergoing chemotherapy. Using a mixed- methods approach to evaluate each intervention component; we will pursue three closely interlinked steps in cancer patients receiving chemotherapy. In Aim 1 (n=12), we will manualize an individualized approach to the yoga breathing intervention and iteratively refine it to insure feasibility and acceptability. In Am 2 (n=24), we will manualize a yoga posture intervention, evaluating both restorative/static poses and flowing poses, and perform iterative refinement to test feasibility and acceptability. In Aim 3 (n=52), we will assess the final multi- modality yoga intervention to select final intervention elements and doses for testing in a planned future RCT. This application will help to improve the treatment of debilitating cancer associated symptoms and advance our approaches to developing therapeutic yoga intervention trials.