Muscle recovery differs between sexes, new study reveals

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. All races and ethnic backgrounds 2. Men and women, age 50-65 years 3. Generally healthy (see exclusion criteria) 4. Able and willing to provide informed consent 5. Ability to speak and read English 6. Post-menopausal women (no menses within the last 12 months) 7. Body mass index: 18.5-35 kg/m2 or BMI\>35 if thigh adiposity does not impair muscle biopsy Exclusion Criteria: 1. Compromised musculoskeletal function that precludes safe participation or use of crutches 2. Pre-menopausal women 3. Hypogonadal men (testosterone \<300 ng/dL) 4. Women taking hormone replacement therapy (HRT) 5. Sarcopenia (European Working Group on Sarcopenia in Older People, EWGSOP102) 6. Clinically significant heart disease (e.g. New York Heart Classification greater than grade II; ischemia) 7. Peripheral vascular disease 8. History of claudication 9. Pulmonary disease 10. History of systemic or pulmonary embolus 11. Uncontrolled blood pressure (systolic BP\>170, diastolic BP\>95 mmHg) 12. Impaired renal function (creatinine \>1.5 mg/dl) 13. Anemia (hematocrit \<33) 14. Untreated thyroid disease (abnormal TSH) 15. A recent history (\<12 months) of GI bleed 16. Diabetes mellitus or other untreated endocrine or metabolic disease 17. Electrolyte abnormalities 18. Any history of stroke, hypo- or hyper-coagulation disorders 19. Employment requiring long (\>1 h) uninterrupted period of standing 20. Inability to meet study travel requirements (e.g. manual geared car) 21. Recent history of balance issues or falls. 22. Recent (3 years) treated cancer other than basal cell carcinoma 23. Systemic steroids, anabolic steroids, growth hormone or immunosuppressant use within 12 months 24. Recent (2 months) adherence to a weight-loss or weight-gain diet 25. Weight change of 5% or more in previous 6 months 26. Body mass index \>30 or excess body fat that compromises muscle biopsy collection 27. Acute infectious disease or chronic infection 28. Alcohol or drug abuse 29. Any other condition or event considered exclusionary by study physician