PI left the university and is no longer in a full time employment role

The regulation of total body water that defines human hydration status is a complex and dynamic process. Current methods of assessing hydration status (e.g. hematologic and urinary analyses) lack the ability to track changes in hydration status in real-time due to whole-body homeostatic physiologic processes required to maintain central pressure and cardiovascular function. This project will address this problem by assessing the relationship between autonomic function (measured using heart rate variability), a brain-derived process that regulates cardiovascular function, and changes in the hydration-mediated hormone vasopressin.

Inclusion Criteria:

• Males and Females between the ages of 18 - 35

Exclusion Criteria:

• 1) evidence of clinically relevant diseases that may alter body water regulation (e.g., diabetes, kidney disease, metabolic disorders, cardiovascular disease, and other potential fluid balance covariates such as habitual use of non-steroidal anti-inflammatory drugs or serotonin reuptake inhibitors,

  2) previous surgery on the digestive tract that may impair the body's ability to normally regulate body water,

  3) regular drug treatment within the previous 15 days,

  4) actively attempting to gain or lose body weight,

  5) For female participants, testing will take place during the early follicular phase of their menstrual cycle (days 1-8) to maintain consistency in the hydration status measures as total body water fluctuates over the course of the menstrual cycle. Females who are currently using contraceptives (e.g., IUD) that limit the number of menstrual cycles occurring in a given year will be excluded from this study to ensure accuracy in the testing periods for this study.