Impact of two brief behavioral theory-driven professional training programs on fitness center attendance: protocol...

Fitness centers are privileged settings for promoting health; however, they are affected by high attrition rates and low attendance. At the same time, several motivational theories are considered relevant to improving behavior in exercise contexts, although they largely lack experimental evidence. Accordingly, the main objective of this study is to examine attendance trajectories following the implementation of two short training programs for exercise professionals, based on two theories of human behavior (self-determination theory and hedonic theory), with fitness center attendance patterns over time. As a secondary objective, the study will examine associations with attrition rates, motivational variables, and other behavioral outcomes. It is hypothesized that the theory-driven interventions will be associated with more favorable attendance trajectories and lower attrition than the control condition. This is a pre-registered, pragmatic, single-blind, controlled intervention study with three parallel arms, in which fitness clubs were randomly allocated across conditions. Professionals will receive brief training sessions according to their assigned condition throughout the intervention period. From September 2025 to August 2026, data on dropouts and training attendance among new clients will be collected. A subsample of exercisers will also be followed longitudinally to assess motivational outcomes. Primary outcomes will be attendance over one year; secondary outcomes will include attrition rate, motivation, intention to continue exercising, behavioral automaticity, subjective affective experience, and enjoyment. Improvements in attendance would reflect individual health gains, while reductions in attrition rates would enhance the financial sustainability of clubs. Moreover, the findings may provide preliminary evidence regarding the practical utility of translating these theoretical approaches into routine professional practice.

ClinicalTrials.gov, identifier NCT07156240.