Adherence to physical activity in an unsupervised setting : the case of lapse and return to practice in a Brazilian fitness center

This study aims to evaluate adherence, dropout, lapse and return rates of members of a fitness center in the city of Rio de Janeiro, Brazil, and the potential explanatory variables for these phenomena. The study was exploratory and observational, using a retrospective longitudinal frame of reference. The records of 5242 individuals, members of the fitness center between Jan-2005 and Jun-2014, were monitored for 12 months after cancellation of membership or until re-enrolment, whichever occurred first. A Cox proportional hazard regression model was adjusted to identify variables associated with higher probability of returning to activities. The general survival curve shows that 38% of members who drop out will return to activities within 12 months. Of those who return, more than half return within the first month. The regression model showed that age, previous level of physical activity and length of membership before dropout are related to the probability of returning earlier to activities after an interruption. Combined, those variables represent an important difference between individuals with the best and worse combination of significant variables. Our results can assist in the identification of high risk individuals and therefore help in the development of strategies to prevent abandonment of physical activity and to increase return after interruption