Hematopoietic cell transplantation (HCT) reduces physical function and muscle mass and increases fatigue. Neuromuscular electrical stimulation (NMES), when used as a stand-alone intervention, improves muscle strength and muscle mass in non-cancer patients with chronic obstructive pulmonary disease and chronic heart failure. The use of NMES to combat disuse atrophy and functional decline may be particularly useful in the HCT setting as patients undergo intensive preparatory chemotherapy and often experience symptoms including severe fatigue that leave them inactive or isolated for extended time periods surrounding the transplant. However, its use in the setting of cancer has not been well-established. This proposal will contribute to developing strategies toward optimizing the safety and outcomes associated with HCT in Veterans with hematologic malignancies. The overall goals of this study are to assess 1) the efficacy of an NMES vs Sham intervention on HCT-induced reductions in physical function and muscle mass and worsening of patient- reported fatigue and QOL and 2) the association between physical function and prolonged recovery of patient- reported fatigue and QOL. We hypothesize that 1) NMES will attenuate the acute HCT-induced negative impact on physical function, body composition, QOL, and fatigue compared to Sham intervention, and 2) baseline physical function will be a significant predictor of 6-month recovery of patient-reported fatigue and QOL. Aim 1: To determine the efficacy of NMES vs. Sham for attenuation of HCT-induced reductions in physical function, muscle mass, and patient-reported QOL and fatigue in patients undergoing autologous HCT. Patients will be randomized 1:1 (NMES:Sham) stratified by diagnosis. Physical function, body composition, QOL, and fatigue will be assessed at baseline (Pre, after admission to the Bone Marrow Transplant Unit but before initiation of preparatory chemotherapy) and 28±5 days after HCT (Follow-up 1; FU1). The primary outcome will be between-group difference in 6MWT change at FU1 compared to Pre (N=23/group; 46 total). Secondary outcomes include: body composition measured by dual-energy x-ray absorptiometry; previously validated questionnaires (Functional Assessment of Chronic Illness Therapy-Fatigue; Muscle and Joint Measures) to assess patient- reported fatigue, QOL, symptom burden, and functional status; standard of care clinical/laboratory data regarding co-morbidities, adverse events, hospitalizations, treatment history, functional status, and clinical course; and NMES process measures such as feasibility, acceptability, adherence in number of sessions, accurate use, duration/intensity, complications, and satisfaction. Aim 2: To determine predictive ability of baseline 6MWT on delayed recovery of physical function, QOL, and fatigue, patient-reported outcomes, physical function, and chart review will be collected 6-months after HCT (FU2). 6MWT at Pre will be used to determine significant predicto...