Challenge: Don't eat fruit today. Make sure to eat lots of veggies to make up for the vitamins and minerals. Re-introduce fruits back in your diet in a day or two and see how you feel. The best time to eat sugary fruits is post-wod. Try it!
(surprised? don't be)
Table of Sugar Content in Fruits
Sugar = Sugar = Sugar...Read me
Perhaps there are some paleo people that have not yet seen Dr. Lustig's 1.5 hour lecture Sugar: The Bitter Truth