Resistance Exercise Dosage in Older Adults: Single- Versus Multiset Effects on Physical Performance and Body Composition
Computing, Health and Science
Exercise, Biomedical and Health Science
Objectives: To determine whether variation in resistance exercise volume affects muscle function and physical performance response in older adults. Design: A randomized trial with subjects assigned to a single-set (1-SET) or three-set (3-SET) exercise group. Setting: An exercise facility at the University of Queensland. Participants: Twenty-eight community-dwelling men and women aged 65 to 78. Intervention: Progressive resistance training consisting of seven exercises targeting the major muscle groups of the upper and lower body performed on exercise machines twice weekly for 20 weeks at eight-repetition maximum (RM) intensity. Measurements: Muscle function included isotonic muscle strength (1-RM) of the seven exercises, isokinetic and isometric knee extensor strength, and muscle endurance for the chest press and leg press exercises. Physical performance included timed chair rise, usual and fast 6-m walk, 6-m backwards walk, 400 m walk, ﬂoor rise to standing, and stair climbing ability. In addition, body composition was determined using dual energy x-ray absorptiometry. Results: Isotonic muscle strength increased in both exercise groups for all seven exercises (Po.01), with the gain in the 3-SET group greater (Po.05) for the seated row, triceps extension, and knee extension (analysis of covariance). Similarly, muscle endurance gains were greater for the 3-SET than the 1-SET group (Po.01), with no significant difference between groups for isokinetic and isometric knee extensor strength. Both groups improved (Po.05) in the chair rise (1-SET, 10.1%; 3-SET, 13.6%), 6-m backwards walk (1-SET, 14.3%; 3-SET, 14.8%), 400-m walk (1-SET, 3.8%; 3-SET, 7.4%), and stair climbing test (1-SET, 7.7%; 3-SET, 6.4%), with the only difference between groups for the 400-m walk (Po.05). There was no difference between groups for change in body composition. Conclusion: Resistance training consisting of only single-set exercises is sufﬁcient to significantly enhance muscle function and physical performance, although muscle strength and endurance gains are greater with highervolume work. These ﬁndings have application in designing time-efﬁcient exercise regimens to enhance neuromuscular function in older adults. J Am Geriatr Soc 53:2090–2097, 2005.