Description: This research study is to assess energetic status, reproductive health, and bone health in a population of young exercising men. Secondarily, this study will also explore how diet, fitness, cardiovascular function, eating behaviors, stress, cognitive function, and sleep related to energy and reproductive outcomes in exercising men. Eligible young men (age 18-35) are those who are generally healthy and either a) exercising or b) not exercising.

There will be essentially 5 study visits - The first visit will include informed consent to take part in the study & completion of questionnaires and measurement of anthropometrics. Visit 2 will include tests of your metabolism, a blood draw, a saliva collection, and assessment of diet and physical activity. Visit 3 will be a short visit for a saliva collection. Visit 4 will include tests of stress (a hair sample), body composition, bone health, aerobic and anaerobic fitness, cognitive testing, and reproductive function. Visit 5 will consist of a results meeting and return of wearable devices and logs.