Exercise Machine Elliptical

Well, first of all I can say is that it is extremely difficult for me to use, I use it for about a minute at a time, so it's really hard on my body, just my legs. and I see people on these machines for 30 minutes plus, and go on no problem, but as soon as I get it, it hurts, really bad. I can Bearly move. and everyone says you can work your entire body with it, if someone told me one day they do all over the body, and the next thing they do less. but I do not understand how to do it. I go up and the only place I can feel it burning in my legs. So how is it? and I have allot of muscles in the legs, so I do not see how this is so painful for me, my sister and she said her heart, there is not much problem with their muscles until wards.so im wondering if I'm doing it wrong; or maybe it's something I can do to change the machine to do less.pain vol. oh and the whole body upper-body/lower out.h