Think of your body / Yourself as an investment
Everything you do during the day is an investment in yourself, and everything you don't do in a day decreases the value of your life. Raw and true. The things you do during the day can either have a positive or negative impact on your life in the future. Let's take a look at this theory from an exercise point of view. Say you do 50 push ups one day, that alone is a good investment, but say you do 50 push ups 6 days a week for 3 weeks. That is an investment that will get you to your eventual goal whatever that may be.
I am not a fan of stocks because you can not determine whether they go up or down, you have little to no control over your money. Adversely, you do have control over your own life and you can determine what steps you will take to achieve a more profitable life.
"The best investment is in yourself."