Let’s get one thing out of the way right now: There’s not going to be any “one method is better 100 percent of the time” here. Both free weights and resistance machines can help you build strength, size, and generally get fit.
They do, however, each have a unique set of strengths and weaknesses. That’s because free weights move freely forward and backward, side to side, and up and down, explains exercise scientist, Ed Hulit, CSCS, project manager at Technogym, which designs and produces top-of-the-line free-weights and machines. That’s all three dimensions, my friends. Weight machines, however, are fixed to an axis, meaning their weights can only move in a specified way—generally in only two planes. Sometimes just one.
It’s important to make that clear, not only because it affects how the muscles train and grow, but because some machines are not fixed and, by and large, actually belong in the free-weight camp, he notes. For instance, cable systems look like machines, but grab ahold of one and you can move its weight wherever you want. There’s no track pre-determining your motion. Machines, however, are only going to let you move that bar up and down. There’s nowhere else to go.