An Ab Machine is a must have at every gym. Most abdominal machines offer a high degree of protection to the abduction and adduction muscles of the lower back which traditional ab exercises such as sit-ups and crunches do not. Someone experiencing less pain is more apt to persevere with their exercise program. Sore lower back muscles can be avoided by well-designed ab machines.
Another important benefit is that by concentrating effort on the primary core muscles, overall core strength is enhanced, providing stability for any and all standing resistance exercises, such as bent over rows, squats, lunges, straight leg deadlifts and even bicep curls.
As long as one uses abdominal machines properly and forgoes unrealistic expectations centered on the myth of spot reducing, they can with regular use contribute to both overall fitness and a toned, firm midsection.