I hunted Iowa this last weekend and saw 36 deer in 3 days. Many ended up in bow range downwind of me. I am a fanatic about scent control except my breathe. Some of the hunts were with scent lock some not. But 30-40 yards out, most of the deer would look up at me as if they knew something wasn't just right when they were downwind. They didn't run off or anything but they were very wary. I think from now on I will take that added measure to help cover my breath by eating apples or doing some of the other things mentioned here.