Weight training “machines” are wonderful, especially if you own a gym, like I do. They are simple to use, relatively safe to use (More on this in a second), they isolate a single muscle group and they get people in and out of the gym fast. When properly used they are quite silent (certainly not as “noisy” as pure barbell training) and are very user friendly. An ideal scenario, or not…
Most machines work on a single plane, be that a push or a pull. They do not give way to the natural movement of the body, and therefore do not work on a three-dimensional plane like free weights do. In certain cases, take the Lying Leg Press for example, they can be outright dangerous if not handled correctly. Let me explain. Generally speaking your lower body is much stronger than your upper body. After all, you walk around all day carrying your body weight. So, if you lie down with your legs above your head for a Lying Leg Press, you need to load more than your body weight to achieve a resistance that will enable STRESS to occur. When you lower the weight it all goes onto your lower back, which flexes under pressure. The risk? A herniated disk. That is exactly what happened to me and the main reason, years ago now, that I completely moved away from any machine work and focused on heavy compound lifting. Not only to get stronger, but to actually recover from my injury, using TRAINING AS MEDICINE.
I could go on and on about the great superiority of using free weights (and specifically the Barbell) compared to a machine, and maybe I will add other articles later on. For now safe to say that the Barbell (and the dumbbell and the Kettle-bell) are by far superior to any machine you will ever come across.
Machines do have some great benefits, especially for recovering from an injury or if one has permanent Biomechanical problems that do not permit the use of free weights.
They are useful for accessory exercises which can support primary Compound movements. They can also be used if you want to give your arms a bit of extra work without putting excess stress on your Central Nervous System. Cable Machines can be quite useful if you feel the need for some extra work, like pec flyes or cable rows, as they do give you some freedom of movement and therefore work on multiple planes, but now we are slowly moving into the world of Body Building, and this is not a Body Building site.
When using proper form, there is nothing a machine can do that can equal to the use of a Barbell, a Dumbbell or a Kettle-bell.
Machines do not encompass a full human movement pattern and do not apply a stress on the axial skeleton, gait, balance or total strength. Machines strengthen muscles, not movement patterns.