Anyone at any age can do aerobics. Ofcourse, you need to consult with your physician first, incase you have some chronic problem. But otherwise, it is a great cardiovascular workout.
Aerobics helps in so many ways! It helps in keeping your heart rate up, burning calories, keeping your muscles active, keeping your body in a balanced & fit shape, and so on.
Aerobics classes are a fun way to lose weight - often because its a group activity, and the chances of getting bored are reduced. Moreover, once you make friends at such classes, you have a source of motivation to continue with the exercise.
Apart from that, Aerobics is great to lose weight, aid in good organ function, and it is BRILLIANT for the heart.