If you want to do your best to maintain great bone density and/or support your bones, then you need to start doing some resistance training. Basically, you need to stay active as soon as you can. That is why it is great to start when you are young, in order to develop great habits. If you are just getting around to this at a later stage in life, it is better to start now, then not start at all.

Thanks,
Oregon Personal Trainer