The Impact of Biological Mechanisms of Aging on Response Variability to Resistance Training in Older Adults (BRIO): A Randomized, Placebo-controlled Trial of Progressive Resistance Training in Older Adults.

Inclusion Criteria: * aged greater than or equal to 65 years * sedentary (Community Healthy Activities Model Program for Seniors physical activity questionnaire to identify and exclude persons engaged in regular (125 min/week or more) moderate intensity physical activity * at risk for mobility disability score of less than or equal to 10 (but greater than 3) on the SPPB * willing to be randomized into HE or PRT * willing to be transported or transport themselves to the clinical sites for the intervention and assessments Exclusion Criteria: * unwillingness to provide informed consent * parti…