Every couple of weeks I end my squat session with 225 to failure, which for me is about 45-50 reps after 3 previous heavy sets. The first 25 reps I do in 5 rep bursts, then take a few deep breaths after each 5 second burst. The last 20-25 reps I do one at a time and breath deep after every rep. Talk about falling on the floor after your done...lol