The Actiwatch-2 (Philips Respironics), a wrist-worn actigraphy device, will be used to objectively quantify circadian rest-activity patterns over a continuous 7-day period using 1-minute sampling epochs at three time points: prior to HSCT and 9 (mid-intervention) and 18 weeks (post-intervention) post-HSCT. The following indices will be calculated: mesor (mean activity level), amplitude (rhythm height), acrophase (time of day the rhythm peaks), and R-squared (robustness of the rhythm). Participants will complete a concurrent nightly sleep log, and traditional sleep parameters will be calculated from both the logs and actigraphy, including total sleep time (TST), sleep onset latency (SOL), wake time after sleep onset (WASO), and sleep efficiency (SE). For daytime activity, calibration thresholds will be used to aggregate activity data into steps and minutes spent in sedentary, light, moderate, and vigorous activity