i started at 17,
im serious, all you have to do is be dedicated to 10mins a night and you'd be surprsied
only reason i stopped lifting weights was 1. my friends took his weights back, (werent mine to begin with) and 2. i moved out of the basement, i have no room for anything now.
but im serious, 3 months is all you need and 10 mins dedication before u goto sleep