I find that doing actual pushups and situps are quite useless, and I find I do better when I am lifting. We do PT 3x a week, I am enver strained after pushups and situps, but the runnign kills me. Anyways, I was usually around a 50pu/2 min person before I lifted (yea, I stopped lifting for a bit when I came to college), anyways, I have maxed (or been like 3 off, grading differences) since I lifted. I never maxed my situps until I started doing weighted crunches HST style. Doing pushups, situps and running on off days will help with the technique.