Recovery, Physiological clinical trials at University of California Health

In this study, the investigators will examine the effect of cold-water immersion (CWI) on objective and subjective recovery metrics, as well as simple performance metrics, in National Collegiate Athletics Association (NCAA) Division I Men's and Women's Volleyball players, Men's Football players, and Men's and Women's Cross Country runners. This is a cohort cross-over study that will take place over the course of four weeks during an intensive training cycle. Participants will wear a WHOOP monitoring device on their wrists at all times during the study period. The two-week intervention will consist of ten minutes of CWI to take place within one hour of the completion of the last training session of the day. The target water temperature will be 55 degrees Fahrenheit, and each participant will complete five sessions of CWI per week (for a total of ten sessions over the two-week intervention phase). Objective recovery measures will include heart rate variability, resting heart rate, total sleep time, slow wave sleep time, sleep consistency, blood oxygenation, and nocturnal skin temperature, all of which will be collected continuously by the WHOOP monitoring device. Subjective recovery measures will include three surveys to be completed daily, including the Likert Scale of Muscle Soreness, the Total Quality Recovery Scale, and the Single-Item Sleep Questionnaire. Performance measures will include a counter-movement jump to be completed two times per week, an isometric mid-thigh pull to be completed once per week, and a drop jump to be completed once per week. These outcome measures will similarly be collected during the two-week control period, during which participants will not have access to CWI following training sessions.