"Purpose" isn't about what you can do for you as much as it is about what you contribute to society and the legacy you leave behind. Lifting weights, eating right, making lots of money, are more lifestyle goals. Purpose is the umbrella under which everything you do fits.
A man needs Long Term Perspective. Every decision you make: job, health, spending, friends, gf/LTR/wife should all be consistent with where you want to go long-term. That's why it'so vitally important to choose a LTR or wife who shares your long-term goals and vision.
I started a business back in 2001. It's my purpose. I'm a gifted public speaker and executive coach. So my purpose in life is to assist others in reaching their true and full potential, mainly in business and their career. I've authored a couple books and have a tv spot so even if I kick the bucket tomorrow, the words I wrote and my spoken word will carry on.