Muscular strength and physical function

Purpose: The purpose of this study was to evaluate the potential associatio n of muscular strength and endurance at baseline with the prevalence of fun ctional limitations at follow-up. Methods: Study participants were 3,069 me n and 589 women (30-52 yr) who received a clinical examination including a strength evaluation at the Cooper Clinic between 1980 and 1989 and responde d to a 1930 mail-back survey. Participants also had to achieve at least 85% of their age-predicted maximal heart rate on a maximal exercise treadmill test and have no history of heart attack, stroke, diabetes, high blood pres sure, cancer, or arthritis at their first visit. A strength index composite score (0-6) was calculated using age- and sex-specific tertiles from bench press, leg press, and sit-up tests. Those scoring 5 or 6 were categorized in the high strength group. Functional health status was assessed by respon ses to questions about the participant's ability to perform light, moderate , and strenuous recreational, household, daily living, and personal care ta sks. Results: After an average follow-up of 5 yr, 7% of men and 12% of wome n reported at least one functional limitation. A logistic regression model including age, aerobic fitness, body mass index, and new health problems at follow-up found that, relative to those with lower levels of strength, the odds of reporting functional limitations at follow-up in men and women cat egorized as having higher levels of strength were 0.56 (95%CI = 0.34, 0.93) and 0.54 (95%CI = 0.21,1.39), respectively. Conclusions: These findings, i f replicated in other populations, suggest that maintenance of strength thr oughout the lifespan may reduce the prevalence of functional limitations.