How do you build the body of a top level athlete? There are many benefits to using free weights instead of weight machines. When using free weights, your muscles are completely engaged as you both lift and balance the weight. Weight machines keep the weights steady and moving in the proper motion. With free weights, it is up to you to maintain proper form and engage your muscles to their fullest extent. From beginner to world class athlete, the results are the same. Free weight training has always been considered the best form of full range intensity exercise.