Clinical Research Directory

Inclusion Criteria: 1. Age 18-40 years 2. Body mass index (BMI) 18-28 kg/m2 3. Weight stable (±10 lbs) in past 2 months 4. Takes part in moderate physical activity for at least 150 minutes/week 5. Currently free of upper or lower body /extremity injury or impairment 6. Comfortable with multiple blood draws 7. Able to commit to the 6-month study duration 8. Agrees to adhere to study requirements. Exclusion Criteria: 1. Current smoker 2. Current clinical diagnosis of an eating disorder 3. Chronic use of non-steroidal anti-inflammatory drugs (NSAIDs). NSAID use is defined as chronic if these medications are taken more than three times a week for more than 12 consecutive weeks. 4. Use of medication incompatible with measurement of reproductive, metabolic, or bone-related hormones (including thyroid medications, glucocorticoids) or which includes anti-coagulants and may interfere with any of the study outcomes 5. Current oligo/amenorrhea in women, not explained by contraceptive use 6. Any metabolic or endocrine disease that affects bone; Individuals taking hormonal therapy for transgender care 7. Currently training for a competitive sporting event or planning to start 8. Weight has fluctuated by 10 pounds or more in the past 2 months based on subject self-report 9. Has been diagnosed with a medical condition, physical or psychological, that currently prevents exercise participation 10. Has suffered a musculoskeletal injury removing them from physical activity for more than a month, within the past two years 11. Currently pregnant or becomes pregnant during the study (as assessed by urine pregnancy tests at 0, 3 \& 6 months) 12. Current asthma diagnosis, defined as experienced symptoms or been prescribed any form of treatment within the last 4 years, or those who have required more than one course of oral steroids or more than one nebulization since the age of 5 (JSP 950), will require a note/permission from treating physician to participate in study. Those who have had a single admission to intensive care or high dependency, or multiple admissions to hospital will be excluded from participating (JSP 950) 13. History of heart condition OR high blood pressure 14. Feeling of pain in the chest during rest, activities of daily living, or physical activity 15. Have lost balance or consciousness due to dizziness in the last 12 months (with the exception of dizziness due to hyperventilation) 16. Treating physician requires subject participates in medically supervised physical activity only 17. History of drug addiction or habitual recreational drug use (2 or more times per month in each of the previous six months) 18. Low bone mineral density indicated as a Z-score \<-1.0 measured by dual-energy x-ray absorptiometry (DXA)