Exercise intervention and use of city premises
The women randomized to exercise intervention were allocated to 27 groups, each including 15–18 attendees. Same groups were maintained in both Tai Chi (‘Taiji’) and gym sessions. No additional support (such as motivational reminders, etc.) was given to women during the trial. The control group received education on fall prevention at the baseline visit and was free to pursue their personal activities as before. The intervention groups were provided with a personal electronic access card for free access to all the city exercise premises including swimming halls, gyms and other sports premises administered by the municipality for the first 12 months. At baseline visit, participants were verbally informed about the possibility to use any of the municipal exercise premises for free, in addition to the scheduled sessions, without any obligation to do so. The card was also obtainable from municipal offices by anyone with a pensioner status for an annual fee of 65 euros.In addition to free use of premises, supervised exercise intervention was carried out during the first 6 months, aiming to improve muscle strength focusing on lower limbs, postural balance, active range of motion and joint mobility. The protocol included a 1-hour circuit type gym session and a 1-hour Tai Chi session each week, with a warm-up and 50 minutes of training. The adherence was measured by women’s participation to supervised sessions, based on logging data of the access cards. Group exercises were discontinued after the initial 6 months. However, women who wanted to continue gym training or Tai Chi at their own expense were not restricted from doing so. No individual modifications were done to training protocol during the intervention. However, in case of health restrictions, women were free to adapt the training with the instructors in a way they felt reasonable and pain-free.