I saw a woman on the Ab Coaster yesterday at the New York Sports Club by Union Square (cute club). I tried it. It is an easty-way-out machine. I don't have a burn today after doing five sets of 25 repetitions with 10 pounds on each side. But maybe I will have one tomrorow. You hold onto handles and just use your lower abdominal muscles to bring up your hips and legs. it's harder to do this on teh stand-up machine with handles or even to lay on the floor and bring up your hips in pulses with your lower abdomiaml muscles. But for a change I suppsoe doing the Ab Coaster may be good. It may work out different muscle fibers. i'll see if I have a burn tomorrow! The more fit you are, the more it takes to give you a burn. ;)
Disclaimer: None of the above information can be taken as a substitute for advice from a medical professional such as a physician.
My third book, Pocket Guide to Fitness, is available on www.louizapatsis.com, http://www.authorhouse.com, www.bn.com and http://www.amazon.com. If you look up my name on those Web sites, you will find my other books The Boy in a Wheelchair and Life, Work and Play: Poems and Short Stories.