<p>Objectives　Approximately 40% of new fitness club (FC) members drop out within the first six months; however, the factors associated with FC membership resignation are largely unknown. This study aimed to identify the association between psychological attitudes toward exercise and FC membership resignation.</p><p>Methods　We conducted a cohort study enrolling participants from 17 FCs. All individuals who became members at FCs between April 1st, 2015 and March 31st, 2016 (n=5,421) were invited to participate in the study, and those who agreed to participate completed a self-administered baseline questionnaire (n=2,934). We excluded participants aged <20 years (n=167) and those with missing values (n=702). Psychological factors were evaluated using the short version of the perceived benefit and barriers to exercise scale. Participants were followed until September 30th, 2016, at which time we assessed the FC membership drop-out rate. Cox proportional-hazards models were used to evaluate the association between perceived benefits/barriers of exercise and FC membership resignation. Sub-analyses were then conducted, stratifying by gender and age group.</p><p>Results　A total of 2,065 participants were included in the analyses. The mean (standard deviation) age was 39.0 (15.0) years and 28.8% were male. Over 10.1 (4.4) months of newly-joined member follow-up, the FC membership drop-out rate was 24.6 instances per 1000 person-months. Multivariable analyses revealed no significant factors associated with FC membership drop-out. However, men aged 40-59 years who had a high physical benefit score and who perceived improving physical fitness as a benefit, were less likely to resign their memberships (hazard ratio [HR], 95% confidence interval [CI], 0.72 [0.52-1.00]). However, women aged <40 years with a high discomfort score and who saw discomfort as a barrier were more likely to resign membership (HR, 1.10 [1.01-1.19]). Women aged 40-59 years with high social benefit scores and who perceived social interaction as a benefit were less likely to resign their memberships, as were women with higher lack of motivation to exercise scores and who perceived lack of motivation as a barrier to exercise (HR for social benefit, 0.84 [0.74-0.97]; HR for lack of motivation, 0.85 [0.73-0.99]). Among both male and female participants aged ≥60 years, higher self-improvement scores, indicating that peer recognition was perceived as a benefit of exercise, was associated with higher HR for drop-out (men, 2.52 [1.10-5.81]; women, 1.31 [1.00-1.72]).</p><p>Conclusions　The results revealed gender and age differences in the association between the perceived benefits/barriers of exercise and FC membership dropout. Implementing programs based on enrollees’ characteristics and psychological factors may contribute to preventing FC dropout in the future.</p>