A home-based, transtheoretical change model designed strength training intervention to increase exercise to prevent osteoporosis in Iranian women aged 40-65 years: a randomized controlled trial.

Physical activity (PA) helps to prevent osteoporosis, but older women are often sedentary. This study used a pre-post randomized controlled design to evaluate a 12-week exercise education intervention program based on the stages of change (SoC) and processes of change from the transtheoretical change model (TTM) to improve adherence with strength and balance training recommendations at levels sufficient to prevent osteoporosis in Iranian women aged 40-65 years. The home-based exercise prescription consisted of strength and balance training that was progressive, individually tailored and included a walking program. Individuals in the training group (n=61) had a positive, significant progression in psychological SoC (P<0.001), whereas no progression in stages occurred in the control group (n=55). After the intervention, the training group demonstrated significant improvements in PA, lower body muscle strength, static and dynamic balance, with no significant changes in the control group. These results support the applicability of the TTM for a PA intervention and indicate that this training program is very effective in improving balance and lower body strength in older women.