Getting a flat tum - any advice?

[SageMother]

Originally Posted by baldmonkee

He probably said that because he doesn't want you to think that "spot reduction" is possible. You can't just do sit ups and crunches and expect to get a defined mid section. You should work your whole body, not just concentrate on problem areas

The brisk walking, or any cardio / aerobic exercise will burn fat. The crunches will build the abs. They can be accomplished simultaneously and there isn't really any reason to wait to ad abdominal exercises.