Comparative Effectiveness of Customary Fit and Strong! vs. Fit and Strong! Plus


This project compares the effectiveness of customary Fit and Strong! — an evidence-based physical activity/behavior change program for older adults with osteoarthritis (OA) — to an enhanced version of the program that also addresses diet and weight. Fit and Strong! targets older adults with osteoarthritis in the lower extremeties, the primary cause of disability in this age group. In a recent randomized trial, the 8-week Fit and Strong! program demonstrated significant benefits on physical activity maintenance at 18 months, improvements in lower extremity stiffness, pain, function, strength, and gait speed, and reductions of anxiety and depression.

Until now, Fit and Strong! has not addressed diet or overweight among program participants. This new research addresses these important issues because obesity may cause or exacerbate arthritis symptoms in the lower extremeties. Data show that weight loss of 5.1 kg over a 10-year period decreases the odds of developing OA in the knee by more than 50%. In 2007, 37% of men and 48% of women 60 years of age and older were obese. Between 2003 and 2009 obesity prevalence, on average, was 54% higher among adults with arthritis compared to those without the condition. Obese persons with arthritis were also 44% more likely to be physically inactive. This rise in obesity prevalence may explain rapid increases in the use of hip and knee replacement surgery in the U.S., which totaled $9.1 billion in 2004. Importantly, a recent metaanalysis has documented a dearth of evidence supporting the efficacy of interventions to decrease weight in older adults.

We address this serious scientific gap by developing and testing Fit and Strong! Plus — an enhanced version of Fit and Strong! that addresses both physical activity and diet. We will incorporate common elements from the ADAPT and ORBIT trials that addressed physical activity, diet and weight loss. Both trials achieved weight loss of approximately 5% at 18 months. We will compare the effectiveness of customary Fit and Strong! to Fit and Strong! Plus over 24 months using an RCT with 400 participants at 3 community sites. Both groups will receive tapered telephone reinforcement to support maintenance of behavior change during months 3 through 24. We will also examine health care use before and after the interventions. We hypothesize that Fit and Strong! Plus participants will show differential, significant improvement in diet behaviors at 2, 6, 12, 18, and 24 months accompanied by significant weight loss (at least 5%) at 6 months that will be maintained at 24 months. Fit and Strong! Plus participants will also show differential statistically significant improvements in physical activity maintenance accompanied by improved lower extremity pain, stiffness, and function as well as depression and anxiety at all time points.

Funding Agency

National Institute on Aging of the National Institutes of Health (Grant No. R01AG039374)


Carol Braunschweig, PhD, RD
Denise M. Hynes, PhD, MPH, RN

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About this grant

This study builds on previous research on Fit and Strong! funded by the NIA and the CDC as well as the ORBIT study.

Related publications

Hughes S, Smith-Ray RL, Shah A, Huber G. Translating Fit and Strong!: lessons learned and next steps. Front Public Health. 2015 Apr 27;2:131. [See abstract.]

Smith-Ray RL, Fitzgibbon ML, Tussing-Humphreys L, Schiffer L, Shah A, Huber GM, Braunschweig C, Campbell RT, Hughes SL. Fit and Strong! Plus: design of a comparative effectiveness evaluation of a weight management program for older adults with osteoarthritis. Contemp Clin Trials. 2014 Mar;37(2):178-88. [See abstract.]