Functional trainers are all in one machines designed to strengthen and tone a variety of muscles at once using cables that take the user through a multi planer movement that would otherwise be more restrictive with traditional free weights.  Functional Trainers are great for pulling, pushing, twisting, lifting, bending, and reaching exercises that can mimic real life movements.  The benefit to the functional trainer is that they are safe and effective all in one machines for any age.  Since the weight stack is selectorized, the functional training machine works great for circuit training and supersets since changing of weight is accomplished so easily.  One machine can also replace the need for multiple other workout items which saves both space and cost.