Try many ways, see what works best for you. Sorry if thats a lame answer, but its really how you figure out how it works. I would break the fast and finish the eating at least 1 hour prior to your workout. Nothing worse than getting close to puking with undigested food in your stomach.
I would not use Zone measurements if using IF, but I would track your intake for awhile with something like www.fitday.com
and make sure you are getting enough of what you need. You can't go wrong with plenty of good meats and veggies thats for sure.