title: Resistance training improves metabolic economy during functional tasks in older adults.
abstract: The purpose of this study was to determine the effect resistance training has on metabolic economy during typical activities of daily living in a geriatric population. Twenty-nine men and women (age: 66.7 +/- 4.4 years, body mass: 72.3 +/- 11.9 kg) participated in a 26-week heavy-resistance training program. Before and after training, heart rate and expiratory gases were measured for subjects performing 3 tasks that would mimic common everyday activities encountered by this population: (a) walking (WLK) at 3 miles per hour (4.8 km x h(-1)), (b) carrying a box (CAR) to simulate holding a bag of groceries with 1 hand (30% of maximal isometric strength) while walking at 2 miles per hour (3.2 km x h(-1)), and (c) climbing stairs (STR). No time by gender interaction was observed for the WLK, CAR, and STR activities; consequently, the values for men and women were pooled. Both strength and fat-free mass increased significantly (p < or = 0.001) after the training protocol, whereas body mass remained constant. Oxygen cost decreased significantly by 6% (p < or = 0.05) only for CAR, whereas the respiratory exchange ratio decreased significantly (p < or = 0.05) for both WLK (0.84-0.81) and STR (0.87-0.83), and heart rate decreased significantly (p < or = 0.05) only for CAR. After the resistance training program, subjects also reported a significant decrease (p < or = 0.05) in perceived exertion during performance of all functional task test conditions. These results suggest that a heavy-resistance training program might affect exercise economy during daily tasks and improve ease of physical activity, thereby providing a possible mechanism for increasing quality of life in an older and geriatric population.
authors.affiliation: Department of Health and Exercise Science, University of Oklahoma, Norman 73109, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hartman
authors.forename: David A
authors.initials: DA
authors.lastname: Fields
authors.forename: Nuala M
authors.initials: NM
authors.lastname: Byrne
authors.forename: Gary R
authors.initials: GR
authors.lastname: Hunter
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001823:Body Composition; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010806:Physical Education and Training / Q000379:methods*; D011659:Pulmonary Gas Exchange / Q000502:physiology*