Purpose: The purpose of this study was to understand the process of exercise adherence in middle aged women. Methods: The qualitative theme analysis method was used. The participants were 11 middle-aged women who had exercised over 6 months. Data were collected through in-depth interviews and recorded by and transcribed immediately. The data were coded with similar meaning and analysis themes with the constant comparative method. Results: The core theme was Stepping Stones Across the Stream (SSAS). The Stone means the adherence factors in exercise. The stream means the interrupting factors in exercise adherence. The subcategories were 1) feeling of developmental crisis, 2) searching for exit (from the developmental crisis), 3) finding a surprising new world (full of fun), 4) confronting the situation of dropout, and 5) adherence to exercise by SSAS. Conclusion: The predisposition of fun in middle aged women for the adherence of exercise should be explored along with more adherent factors.