1) Working out in the heat of the day is seriously poor time management. Our century old, 2nd-floor apartment gets waaaay too hot at noon in mid-May! We figured this out after Day 2, when we were changing from workout clothes into fly-fishing gear in order to be properly dressed for the rivers of sweat. Day 3, actually completed post-midnight (being married to an officer = no more 'normal' days), went so much better.
2) EAT MORE FOOD. We were both super tired and not real hungry after recovery drinks, showers, etc. last night, so instead of eating that 5th meal we went to bed. Justin ate a good breakfast, but I skimped on portions at breakfast and then again at lunch because my work schedule picked up... before you knew it, 6 o'clock rolled around and I felt super light headed and exhausted. Definitely follow a meal plan, because no matter how much your head says "I can wait, I'm not that hungry" your body is screaming "FEEEED MEEE!" when doing Insanity.