C-Protein in Fatigue and Aging

Eligibility Criteria

• * Adults between the ages 18-35 or 65-80 years
• * Healthy by self-report
• * Willing to participate in all aspects of the study design including muscle biopsy, unilateral exercise, and physical activity monitoring
• * Fluent in English (due to lack of translation services, it is not practical to conduct the study using a language other than English).
• * Orthopaedic limitation (severe knee osteoarthritis, prior joint replacement, etc.).
• * Volunteer has dementia or related mental issues that potentially put the subject at risk as determined by prior diagnosis.
• * Volunteer has known untreated endocrine disease (hypo/hyper thyroidism, Addison's Disease or Cushing's syndrome, etc.)
• * Volunteer has untreated/poorly-controlled hypertension (stage 2, per American College of Cardiology \[\>140/90 mmHg\]).
• * Volunteer has significant heart, liver, kidney or respiratory disease.
• * Volunteer has diabetes (insulin dependent or non-insulin dependent).
• * Volunteer has known coagulopathies.
• * Volunteer has taken anabolic steroids in the prior six months.
• * Volunteer has received treatment for cancer (other than effective Mohs Surgery for successful removal of basal cell or squamous cell carcinomas)
• * Unexpected weight loss \>5kg is last 12 months
• * Volunteer is an active smoker or quit within the last year.
• * Volunteer has known current alcohol or drug use disorder (AUD; defined as binge drinking of \>4 days in the last month. Binge drinking is \>5 drinks for men and \>4 drinks for women, per occasion). Or, if a volunteer reports drinking in excess of "low risk" per NIAAA (\>7 drinks/week for men and \>3 drinks/day for women and \>14 drinks/week and \>4 drinks/day).
• * Volunteer has a diagnosed neuromuscular disorder.
• * Volunteer has allergy to lidocaine.