kegals

Yes, you can do it at any age.
Your anus is attached to the PC muscle so it will contract also.
The PC muscle starts about the top of the pelvic bone ( just above the penis, or pubic hair line) and continues back just above the anus, spreading across the buttocks. You will feel a pull in all of those areas as you do your kegals.
A great way to tell if you are doing them right is to try to stop a stream of urine.
Stopping a stream of urine shows you how hard you have to ' squeeze' to successfully work your PC muscle.