You bet it does. Biking is a great "soft" sport. Soft meaning it's not hard on your joints like say running. Just make sure you have the seat propperly adjusted to your height and leg length (there should only be a slight bend when your leg is fully extended) and you wear your helmet

Any activity that gets your heart going is good for you. If you're going for longer than 20 minutes bring some water with you and sip from it every 15 minutes or so; its important to keep hydrated. And if you havent been riding since you were 18 take a couple of test drives in a quiet neigbourhood first.

Happy biking!
Nat