title: Predictors of Change in Physical Function in Older Adults in Response to Long-Term, Structured Physical Activity: The LIFE Study.
abstract: To evaluate the extent of variability in functional responses in participants in the Lifestyle Interventions and Independence for Elders (LIFE) study and to identify the relative contributions of intervention adherence, physical activity, and demographic and health characteristics to this variability.
  
  
  
  Secondary analysis.
  
  
  
  Multicenter institutions.
  
  
  
  A volunteer sample (N=1635) of sedentary men and women aged 70 to 89 years who were able to walk 400m but had physical limitations, defined as a Short Physical Performance Battery (SPPB) score of ≤9.
  
  
  
  Moderate-intensity physical activity (n=818) consisting of aerobic, resistance, and flexibility exercises performed both center-based (2times/wk) and home-based (3-4times/wk) sessions or health education program (n=817) consisting of weekly to monthly workshops covering relevant health information.
  
  
  
  Physical function (gait speed over 400m) and lower extremity function (SPPB score) assessed at baseline and 6, 12, and 24 months.
  
  
  
  Greater baseline physical function (gait speed, SPPB score) was negatively associated with change in gait speed (regression coefficient β=-.185; P<.001) and change in SPPB score (β=-.365; P<.001), whereas higher number of steps per day measured by accelerometry was positively associated with change in gait speed (β=.035; P<.001) and change in SPPB score (β=.525; P<.001). Other baseline factors associated with positive change in gait speed and/or SPPB score include younger age (P<.001), lower body mass index (P<.001), and higher self-reported physical activity (P=.002).
  
  
  
  Several demographic and physical activity-related factors were associated with the extent of change in functional outcomes in participants in the LIFE study. These factors should be considered when designing interventions for improving physical function in older adults with limited mobility.
authors: Department of Applied Physiology & Kinesiology, University of Florida, Gainesville, FL.
authors: Andrew S
authors: AS
authors: Layne
authors: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC.
authors: Fang-Chi
authors: FC
authors: Hsu
authors: Department of Exercise Science, Department of Epidemiology/Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC.
authors: Steven N
authors: SN
authors: Blair
authors: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, NC.
authors: Shyh-Huei
authors: SH
authors: Chen
authors: School of Nursing, Duke University, Durham, NC.
authors: Jennifer
authors: J
authors: Dungan
authors: Nutrition, Exercise, Physiology, and Sarcopenia Laboratory, U.S. Department of Agriculture Jean Mayer Human Nutrition Research Center on Aging, Tufts University, Boston, MA.
authors: Roger A
authors: RA
authors: Fielding
authors: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA.
authors: Nancy W
authors: NW
authors: Glynn
authors: Department of Internal Medicine, Section of Geriatrics, Yale School of Medicine, Yale University, New Haven, CT.
authors: Alexandra M
authors: AM
authors: Hajduk
authors: Department of Health Research and Policy, School of Medicine, Stanford University, Palo Alto, CA.
authors: Abby C
authors: AC
authors: King
authors: Department of Aging & Geriatric Research, University of Florida, Gainesville, FL.
authors: Todd M
authors: TM
authors: Manini
authors: Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC.
authors: Anthony P
authors: AP
authors: Marsh
authors: Department of Aging & Geriatric Research, University of Florida, Gainesville, FL.
authors: Marco
authors: M
authors: Pahor
authors: Department of Preventive Medicine, Northwestern University, Chicago, IL.
authors: Christine A
authors: CA
authors: Pellegrini
authors: Department of Aging & Geriatric Research, University of Florida, Gainesville, FL. Electronic address: tbuford@ufl.edu.
authors: Thomas W
authors: TW
authors: Buford
mesh_terms: D061725:Accelerometry; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D015992:Body Mass Index; D015444:Exercise / Q000502:physiology*; D005260:Female; D006266:Health Education; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D051346:Mobility Limitation; D010349:Patient Compliance; D064797:Physical Conditioning, Human / Q000379:methods; D055070:Resistance Training; D057185:Sedentary Behavior; D013997:Time Factors; D000072797:Walking Speed / Q000502:physiology
keywords: Aging; Exercise; Individuality; Rehabilitation; Resistance training; Walking