Health and fitness apps support health goals but have lower retention rates compared to other mHealth apps in China. Young people in China experience numerous physical activity issues: body dissatisfaction, insufficient physical activity, and disordered eating behaviours. Most Chinese fitness apps rely on motivational features such as exercise tracking, social communities, or live streaming influence to attract users [1, 2]. However, they do not promote a holistic healthy lifestyle to users. Our research reviewed current case studies to discuss the main features of the fitness apps: goal-setting, fitness influencers and gamification. We adopted co-design approaches involving twenty young Chinese adults and conducted research in four phases: user studies, ideating features, prototype tests, and evaluating implementations. Participants’ insights suggested one motivational strategy (Gamification, Relaxation, Mutual Growth, and Music) and provided a design model GEMM for improving User Experience (UX) in fitness app design.