Is it Real Strength or are you Slave to a Machine?

Promising I'd revisit this topic from an older post, I'm back to open this can of worms.

Occasionally, a new client will ask me to show him/her how to use the machines in the gym. It's a legitimate request coming from someone unfamiliar with the equipment having the desire to get a good workout when they come to the gym themselves. The presence of the machines do seem to offer a shortcut to a better workout. However, the only shortcut you'll be getting from a machine is a shortchange on real strength and quality muscle.

I overheard another trainer explaining to a new client that on most machines there were only two adjustments to be made: The seat height and the amount of weight to be used. Sit down, push or pull, that's it. And that is it. Your biceps, triceps, or lats will get a nice workout but you'll use few stabilizer muscles, if any. That's fine if you wanna look pretty, but don't complain when you hurt your back picking-up a bag of groceries. Or, in other words, that muscle is of little use off of that machine.

Muscles don't work in isolation and you shouldn't be thinking they can be trained that way (muscle isolation is not possible on garden-variety gym equipment). Most muscles work in pairs: agonists and antagonists. When you raise your arm towards your shoulder the biceps muscle (the agonist), contracts. When you lower your arm the triceps muscle (the antagonist) contracts. This action is also a stabilizing force for joints.

If you're content with the results of your machine-based workout, that's great. If not, then arm yourself with a great weight lifting or bodybuilding guide or hire a personal trainer who will show you how to use free weights and cables to grow quality muscle.