i plan on joining the Marines in a few years(when i graduate high school), and right now i am trying to get the best possible score for the PFT(physical fitness test). i am great with the pullups and the running part but i have trouble with the situps. the situp requirements are to lay on your back with you knees bent and you ankles touching your ass, and then you have your arms crossed over your stomach and when you situp, the forearms have to touch the thighs. i can only get my forerms to about 4-5 inches away from there. i do many situps and i have very hard abs(although they arent very well defined)...do i need to do weighted situps or something to get them stronger? or do they expect us to use momentum to get our forearms to the thighs?