user: Question: What is the ab ripper x when exercise is X Stretch?
Columns: ['Program', 'Exercise', 'Week', 'Muscles Worked', 'Type', 'Ab Ripper X', 'Length', 'Equipment']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['P90X', 'Yoga X', '1-13', 'Full Body', 'Cardio, Stretch', 'No', '92:24', 'Mat, Yoga blocks, Water and towel']
SQL:

assistant: SELECT "Ab Ripper X" FROM "Table" WHERE "Exercise" = 'X Stretch';