Ellipticals are the fastest growing type of cardiovascular exercise equipment. Elliptical cross trainers offer a low impact workout that exercises muscle groups in both the upper and lower body with minimum strain on joints. A smooth elliptical cross trainer is generally designed with a 3-1 ratio of lower body to upper body resistance, matching the body's normal ratio of upper to lower body muscle mass. What makes this piece of fitness equipment unique is that Ellipticals enable you to work out equally with all four limbs, valuable for longer fat burning workout programmes. The elliptical leg motion, coupled with arm resistance exercise, provides a fitness workout that many find especially pleasing. Forward and reverse action maximises the benefits of using an elliptical cross trainer.