I say live life the way that feels right to you!
If you find that you're worried about ageing and you're wrapped up in thinking of ways to postpone the enevitable, then you've not got much more quality of life than a heroin addict, who spends all of his life wrapped up in where his next fix is coming from. All of us are going to die at some point, so just accept it and enjoy whatever life throws at you.
I will welcome old age when it comes and count myself lucky, as no more than half the people alive today will probably get the chance to experience the joys of old age. Just think about it. After 50/60 years or so, you can start to think about retiring from work, reaping the benefits of well earned pensions! And you can borrow the grandchildren, spoil them, give them back. You can get people to do things for you that you can no longer be bothered to do, and you'll even be able to get away with moaning at them for not doing it right hehehehe
I say, life is what you make of it, if you're not happy, you aint doing it right!