Bodybuilding is more fractured on opinion than anything else I know of. Everyone has their own opinions, beliefs and methods… but if there is one single thing that I think the absolute majority of people agree on is… free weights are always advocated above machines… simply because they do a better job of building muscle.
A good workout program will always have at the core of it free weight routines. Machines are there for assistance exercises mainly, and for providing stability or alternative methods of working certain body parts that can’t otherwise be done.
For instance, some people have such a hard time squatting that they’ll use the leg press machine or hack machine or smith machine.
The problem with machines is they run along straight lines. They aren’t natural, and the body responds best to natural, free movements.
The human body receives far more nervous stimulation and responds best when it’s free to move, wobble, rattle and shake. Every single rep you perform with free weights – although it may not seem like it until the very end when you approach failure – you are constantly using muscle and nerve energy to stabilize the weight you are lifting. This element is completely missing when you use machines.
Another problem with machines is, you can only lift the way they want you to. Everyone is built differently. For some, the machines may be able to provide perfect range of motion, and a smooth, comfortable movement. For others, the machine may force them into an uncomfortable or unnatural position. Free weights allow you to adjust and lift just as nature intended for you to lift – the way in which you are most comfortable.
Yes, machines have their use, but I think anyone who makes up their programs core with machines is missing out on a lot of the benefits free weights can provide. If you need to use machines for certain exercises – such as leg work – then by all means, do so, but don’t become a machine junkie. The fact is, if machines worked as well at building muscle as free weights do, the humble barbell and dumbbell would be nothing but relics of yesteryear in a museum by now. But they’re not, and probably never will be.