Promotion of physical activity among the elderly: Does need-supportive coaching offer an added value to physical and psychological parameters?

Introduction The physical and psychological benefits of regular physical activity are well established in different population groups. Moreover, the positive effects of lifestyle programs compared with traditional exercise programs have been shown. Nevertheless there is no consensus concerning how to optimally assist people in pursuing and maintaining a physically active lifestyle. A theory-driven framework, which can explain the underlying processes and role of a well-skilled coach, is mostly lacking. This study tested the relative impact of an individualized and need-supportive physical activity coaching, based on the principles of the self-determination theory, compared with less intensive coaching procedures on several physical and psychological parameters. Methods The study took place in 4 different regions in Flanders. In total 557 people over the age of 60, recruited through different channels, were randomly allocated to one out of three physical activity intervention strategies: 1) a sport promotion group, in which the coach clarified and referred the seniors to the existing local opportunities; 2) a walking instruction group, in which the coach explained a prestructured walking program that seniors could accomplish on their own or in a social context; 3) and an individualized need-supportive coaching group, in which the coach set up an individualized physical activity program in consultation with the senior and contacted the participants regularly in order to direct the program if needed. The intervention lasted 10 weeks. Multiple physical and psychological parameters were measured at the beginning and after completion of the intervention. Results Physical Activity Analyses indicated a significant increase in self-reported physical activity level in all intervention groups (p=0.000). However, there were no significant differences between the three groups after 10 weeks of intervention (p=0.107). More objective measurements with a step counter, assessing the total amount of steps during 5 consecutive days, confirmed these results (time-effect: p=0.000; time by group-effect: p=0.365). Only the total amount of aerobic steps, which pointed to walking intervals of at least 10 minutes without interruption, resulted in a significant increase in the walking group compared with the promotion group (p=0.003). Physical Fitness Parameters Analogous to the results of physical activity and except for the heart rate at 30 Watt, all physical fitness parameters showed a significant improvement over time (all p<0.05). The only significant difference between the groups emerged on the walking distance in the 6-minutes walking test. More specifically, the increase in walking distance was higher in the coaching and walking groups compared with the promotion group (p<0.05). Psychological Parameters After 10 weeks, there was a significant improvement in all groups in perceived social support from family, self-determined regulation, physical and psychological well-being, anxiety and self-efficacy (all p=0.000). No significant differences between the intervention groups were found, except for perceived social support from medical staff, which increased in the promotion and walking groups while stagnation was indicated in the coaching group (p=0.015). An evaluation of the coach after the intervention demonstrated significant better results in reported autonomy, competence and relatedness, the three core principles of the self-determination theory, in the coaching group compared with the other intervention groups (p