Jean Chatzky is the financial editor for NBC’s Today and is AARP’s personal finance ambassador. She’s also a best-selling author, and in her new book Age Proof: Living Longer Without Running Out of Money or Breaking a Hip, she offers a tip on the No. 1 investment you can make. It’s an investment that won’t cost you a cent — and could save you hundreds of thousands of dollars.

Find out why she says strengthening your health-wealth connection is the most important thing you can do to take care of money for the long-run.

Click here to visit Jean’s website to learn more of her tips and to listen to her podcast Her Money.