I use to go 4-5 days a week. With my work schedule I only get about 6.5 hrs of sleep to be there at 8:30. I'm now going to try and go 3 days a week to see if getting more rest helps out. When I was going 4-5 days a week, I think I was putting too much stress on myself without enough rest. So I'll see how it goes.
By the way, weight lifting burns more fat than cardio. If you end up joining a crossit gym, they will instruct you on proper lifting technique and form.