My job has some upper body intensive work I use to simulate pushup. When I get my weight down to about 190, I plan to start doing real ones. My son asked me if I could do 20 before he went in the AIr Force. I did. He went to basic and did 74 pushups, 72 situps 15 pullups and ran ran the 1 1/2 mile in 8:36. The calesthenics were done in one minute each with a 2 minute rest between the different ones. The run was done after a two minute rest from the pullups. Now he can do 92 pushups in a two minute window where there is no stopping allowed. In his SPecial forces training, you must work to the two minute time or to muscle failure, so he paces them out to last two minutes. Then he found out the record is "only" 120...so now he plans to shoot for that. He said the two minute test is much more difficult then slamming them out for a minute. The pullups are still a one minute test and he can do 16 now. His situps are 86 I think...in the 80's somewhere. Anyway, this inspires me in my quest to get back into cycling. He graduated basic in June. I was 212 then. Now I am 205 and dropping steadily with the riding starting last week. For us, I have to agree crunches are better than situps. For young military pups, situps seem to work fine. They are done with knees up and a helper holding the legs. The biggest problem CHris has is a scar on his lower back from abrasion...did way more than the above during his pararescue phase one.