Optimizing Strength Training in Older Adults

Inclusion Criteria: * Males and females aged 65 years and above * Inactive lifestyle (\< 150 min per week of moderate intensity physical activity) and not regularly participating in a structured strength training program * Planning to reside in the area for the duration of the study Exclusion Criteria: * Severe cardiac disease, including Class III or IV congestive heart failure, clinically significant aortic stenosis, history of cardiac arrest, use of a cardiac defibrillator, or uncontrolled angina * Lung disease requiring either oral or injected steroids, or the use of supplemental oxygen * Short, portable mental status questionnaire with 3 or more errors * Severe arthritis (either osteoarthritis or rheumatoid arthritis) * Cancer requiring treatment in the past 1 year (melanomas excluded) * Development of chest pain or severe shortness of breath during the 6 min self-paced walk test * Parkinson's disease or other serious neurological disorders * Renal disease requiring dialysis * Current diagnosis of schizophrenia, other psychotic disorders, or bipolar disorder * Current consumption of more than 14 alcoholic drinks per week * Severe lower back or shoulder pain that may worsen with weightlifting exercises * Undergoing physical therapy involving the lower extremities * Living in nursing homes, assisted living facilities or other similar institutions * Currently enrolled in another randomized trial involving a pharmaceutical or lifestyle intervention * Weight change (intentional or not) over the last 6 months of \> 5% of body weight, or plan to lose or gain weight during the study * Any other cardiovascular, pulmonary, orthopedic, neurologic, or other conditions that would preclude participation and successful completion of the protocol Temporary Exclusion Criteria A person meeting any of the following temporary exclusion criteria at the time of screening will not be enrolled but may be re-screened later. * Severe hypertension, e.g., SBP \> 200 mm Hg, DBP \> 110 mm Hg * Major surgery or fracture or hip/knee replacement within the last 6 months * Hospitalization within the last 6 months (excluding ER visits)