How many crunches does it take to get great abs?

Experts recommend one or two sets of ten to 20 crunches every other day, but with a caveat. No magic number of crunches will get great abs, according to AZCentral.com, because crunches are only effective when combined with a healthy diet and other exercise.

While doing crunches can strengthen and tone the abdominal muscles, losing fat requires additional activity. The Centers for Disease Control and Prevention recommends a minimum of 150 minutes of moderate activity each week to stay in shape, for a total of 2.5 hours. For highest effectiveness, the CDC recommends a combination of muscle-strengthening exercises and moderate to vigorous cardio activity.