Submit a tip
Do you have info to share with HuffPost reporters? Here’s how.
Former elite marathoner and triathlete; Author, 'The Primal Blueprint'
Mark Sisson is a former elite marathoner and triathlete. He is the author of the best-selling health and fitness book, "The Primal Blueprint", and publisher of the health blog, MarksDailyApple.com.
Do you have info to share with HuffPost reporters? Here’s how.
By entering your email and clicking Sign Up, you're agreeing to let us send you customized marketing messages about us and our advertising partners. You are also agreeing to our Terms of Service and Privacy Policy.