I've been able to leg press over 1000lbs. since I was 16. That was on an actual plate loaded leg press. Not a hip sled. I couldnt go over 1000lbs. on a hip sled until I was 18. The basic difference is range of motion. A leg press is more "natural" when movements are compared. Anyway, I sometimes get sore ankles. I think if you can control the weight, you'll be fine. I have heard of people breaking bones on heavy squats, not leg press though. It could happen though. If you are that concerned ypou should go to your doctor and get your bone density checked out. Not sure what else to tell ya, except lift hard and "break a leg"!