I have not yet applied but I have tried to train myself to be slightly ready. I have done pushups and sit-ups and I know how to swim. But I am concerned that I am not using the right technique. I cannot bring my chest too close to the floor without touching it or it is physically impossible for me to push back up, I have to lower my chest all the way. And it is much easier for me and less painful for my back to have my hands behind my neck when I situp. Do I have to adhere to a certain technique?