title: Relationships between physical activity and muscular strength among healthy adults across the lifespan.
abstract: The purpose of this study was to examine relationships between objective and self-report measures of physical activity and muscle strength among healthy adults ranging in age from 20 to 91 years. Participants (n = 412) were mostly Caucasian men (48 %) and women (52 %) 43.9 ± 16.1 year of age with a body mass index (BMI) of 26.4 ± 4.8 kg/m(2). Physical activity was measured objectively with an accelerometer and by self-report with the Paffenbarger Physical Activity Questionnaire. Upper and lower body muscle strength were measured with an isokinetic dynamometer and handgrip strength with a static dynamometer. Multivariate regression assessed relationships between physical activity and muscle strength. The strongest correlates of upper body strength including handgrip strength were gender (r = -0.861 to -0.716), age (r = -0.445 to -0.241), BMI (r = 0.134-0.397), and physical activity (r = 0.093-0.186). The strongest correlates of lower body strength were gender (r = -0.772 to -0.634), age (r = -0.663 to -0.445), BMI (r = 0.160-0.266), and physical activity (r = -0.139 to 0.151). The strongest correlates of muscle strength were gender (explaining 40-74 % of the variance), age (6-44 %), and BMI (2-16 %), while physical activity correlations were weaker (1-3 %). Conflict surrounding the influence of a physically active lifestyle on muscle strength with age may be due to the stronger influences of other factors that supersede those of physical activity whether measured objectively or by self-report methods.
authors.affiliation: University of Connecticut, 2095 Hillside Rd Unit 1110, Storrs, CT 06269 USA ; 31 Silversmith Rd, Unionville, CT 06085 USA.
authors.forename: Allie
authors.initials: A
authors.lastname: Leblanc
authors.affiliation: University of Connecticut, 2095 Hillside Rd Unit 1110, Storrs, CT 06269 USA.
authors.forename: Linda S
authors.initials: LS
authors.lastname: Pescatello
authors.affiliation: Division of Cardiology, Henry Low Heart Center, Hartford Hospital, 80 Seymour St, Hartford, CT 06102 USA.
authors.forename: Beth A
authors.initials: BA
authors.lastname: Taylor
authors.affiliation: Division of Cardiology, Henry Low Heart Center, Hartford Hospital, 80 Seymour St, Hartford, CT 06102 USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Capizzi
authors.affiliation: University of Massachusetts, 110 Totmann Building, 30 Eastman Lane, Amherst, MA 01003 USA.
authors.forename: Priscilla M
authors.initials: PM
authors.lastname: Clarkson
authors.affiliation: University of Connecticut, 2095 Hillside Rd Unit 1110, Storrs, CT 06269 USA.
authors.forename: C
authors.initials: C
authors.lastname: Michael White
authors.affiliation: Division of Cardiology, Henry Low Heart Center, Hartford Hospital, 80 Seymour St, Hartford, CT 06102 USA.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Thompson
keywords: Accelerometer; Aging; Classification; Isokinetic dynamometer; Methods; Muscle strength; Physical activity