Regular physical activity is essential for health promotion, yet participation patterns and the motivational determinants of exercise vary widely among recreational exercisers. This study examined exercise behavior and motivational profiles among members of two Hungarian fitness centers using the Physical Activity and Leisure Motivation Scale (PALMS). A cross-sectional survey was completed by 1087 adults, assessing demographics, BMI, exercise frequency, service use, and eight motivational dimensions. Health- and body-related motives were most strongly endorsed, while intrinsic motives (Mastery, Enjoyment) and social or external motives showed greater variability. Exercise frequency was positively associated with Mastery and Competition/Ego motivation, and regression analysis identified Mastery as a significant predictor of attendance, whereas age and female gender were negative predictors. Appearance motivation was positively related to BMI, Affiliation predicted participation in group fitness classes, and Others’ Expectations predicted the use of personal training services. Significant gender- and age-specific motivational differences were also observed. The findings demonstrate that although health and appearance motives dominate, intrinsic and social motives are more strongly linked to sustained engagement. These results highlight the need for motivation-sensitive approaches in fitness programming and public health strategies aimed at promoting long-term exercise adherence and disease prevention.