Study Pinpoints Critical Periods That Turn Occasional Gym Visits Into Steady Habits

Sustaining an exercise routine is one of the most persistent challenges in health behavior, and a new open-access study in EPJ Data Science examines why some gym members manage it while others drift away. Using data from Mars Athletic Club, Türkiye’s largest sports chain, researchers set out to identify the specific periods during which attendance matters most for building a lasting gym habit, and to test which interventions actually help members get there.

The team developed a survival metric based on gym attendance patterns, allowing them to pinpoint critical windows in a member’s journey and to segment members into distinct clusters according to their visit behavior. This segmentation meant the analysis could distinguish between members with different visit patterns, rather than treating the membership as a single homogeneous group.

With those segments in place, the researchers compared how different subgroups responded to interventions such as group classes, personal trainer sessions, and visiting different clubs. Their analysis revealed significant differences across clusters: what works for one type of member does not necessarily work for another, underscoring the value of matching interventions to attendance profiles instead of applying one-size-fits-all programs.

To move beyond simple correlations, the study employed causal inference analysis. This allowed the authors to argue not merely that certain factors accompany long-term engagement, but that they drive it. On this basis, they report that personalized guidance and social dynamics are key drivers of sustained, long-term engagement with the gym.

Combined with the effect of personalized guidance, the results suggest that the environment a gym creates, including classes and trainer interactions, can shape whether a newcomer’s early visits harden into a durable routine.

The practical implication the authors draw is a tailored, multi-dimensional approach to promoting exercise habits. Rather than relying on a single lever, they argue that effective strategies should integrate social dynamics, personalized guidance, and strategically timed interventions, with the timing informed by the critical periods their survival metric identifies.

The authors frame this as a way to address the well-recognized gap between the widespread health benefits of regular exercise and the difficulty many people face in sustaining it.

The article, published on 9 September 2026 and available open access, was authored by Ege Demirci, Efe Tüzün, Ahmet Furkan Ün, Taner Giray Sönmez and Onur Varol. As with any observational study of a single fitness chain, the findings are grounded in that specific membership population, and readers should interpret the causal claims within the scope of the data and methods the authors describe.

Subject of Research: Causal drivers of sustained gym attendance and exercise habit formation in fitness club members

Article Title: From occasional to steady: causal drivers of sustained gym attendance in a large-scale fitness study

Article References: Demirci, E., Tüzün, E., Ün, A. F., Sönmez, T. G., & Varol, O. (2026). From occasional to steady: causal drivers of sustained gym attendance in a large-scale fitness study. EPJ Data Science. https://doi.org/10.1140/epjds/s13688-026-00700-y

Image Credits: AI Generated

DOI: 10.1140/epjds/s13688-026-00700-y

Keywords: gym attendance, exercise habits, habit formation, causal inference, survival analysis, behavioral data, personal training, group classes, social dynamics, fitness clubs, physical activity, EPJ Data Science