405... when you're doing leg raises and such... what are you doing them on? Are you doing them suspended? Not sure if your gym has them but if not; buy these:

http://www.thefitnessoutlet.com/body...hannelid=FROOG

My gym didn't have them so I bought some and bring my own. I just hang from whatever I can find and those things work best IMHO because you can focus on keeping your core tight and controlled instead of worrying about hanging.