If you're the sort of person who reads fitness blogs (and if you're not, what are you doing here?) you probably are not a big fan of exercise machines. To be honest, they don't rock my world either. They work muscles in isolation, in only a single plane of motion, which is not the way our bodies operate in real life. Exercises that require coordinated muscle action, and that are multiplanar, are my preference, and they're probably yours too.
But guess what? We're not typical.
Take a minute and try to imagine the mindset of, say, a 57-year-old woman who has never exercised in her life, who doesn't enjoy movement, who isn't comfortable in the gym environment, but knows she needs to begin an exercise program to improve her blood lipid profile and prevent bone loss. The worst thing I could do would be to set her up with a bunch of complex-seeming functional exercises. They might be totally appropriate from an exercise-physiology standpoint, but how much good are they going to do her if she's too intimidated to actually do them? If she's an affluent woman who can afford to work out with me every time she comes to the gym, there's a lot I can do to increase her comfort level with free weights and functional exercise in general ... but most of the wellness seekers I meet are not so fortunate. All too often they can't afford more than a session or two, or at least they think they can't. (More on that some other time. For now, assume they really can't afford more than a session or two with me.) For these people, the best I can do for them is to come up with something they will actually come to the gym and do on their own, with enough consistency to get results, at least until they can scrape together enough money to buy more sessions with me.
Enter The Exercise Machine!
Don't ask me why, but novice exercisers seem to be less intimidated by machines than by free weights. Honestly, I wish they were more intimidated by machines because there's every bit as much injury potential with machines as there is with free weights--maybe more, even--but most people seem not to realize it. To use machines safely and correctly you still need a certain amount of joint stability and core strength, and if these are lacking you will hurt yourself. The seated leg press machine is one of the worst offenders, to the point that I steer people away from it unless I know they've got sufficient core strength to maintain a neutral spine as they push with their legs. But if they can do that .... well, I'd really rather they do squats, lunges and deadlifts, but if that's not going to happen I'd rather they do leg press than nothing at all.
I will admit, there are a couple of machines that I believe were invented by the Devil expressly to try my patience. The seated spinal flexion machine, for instance--don't even get me started. I fantasize about sneaking into the gym at night and smashing it with a kettlebell. Someday I will do it, I swear. In all seriousness I do believe that for most people this machine is unsafe and sets them up for low back pain by encouraging an unnatural movement pattern. Hip flexion good, spinal flexion bad. I will sew those words on a sampler someday.
But most of the other machines are safe enough if used properly. Occasionally I will encounter someone who is simply too tiny or too tall for a given machine, but for the most part it's possible to find settings that are fairly biomechanically correct and won't doesn't stress the joint unduly. Of course the joints can still be destabilized via muscle imbalances that can arise when muscle groups are trained in isolation, but that's more of a potential problem that can be addressed by making sure the overall program is well balanced, with equal attention paid to opposing muscle groups. No leg extensions without leg curls, no chest presses without back rows--that sort of thing.
Okay, so (most) machines can be safe (enough). But are they effective? Hell, yes. If you don't believe me, google Wayne Westcott. He's one of my favorite exercise scientists, mostly because his name makes him sound like the mild-mannered alter ego of a cartoon superhero. But he's also done some very interesting studies demonstrating the benefits of a machine based exercise program across all age groups. In one such study over 1,100 participants ranging in age from 20 to 80 were set up with a very basic program of machine based resistance training and moderate intensity (70-80% MHR) cardio , about 1/2 hour of each, performed 3x per week. Over the course of 8 weeks all participants lost body fat and gained muscle, with the greatest muscle gains (2.4 lbs) manifested in the 61-80 age group. I don't know about you, but I find that to be fairly compelling evidence of the benefits of machine-based exercise.
Would they have made even greater gains if they'd been training with free weights? Probably ... if they'd stuck with it. But many of them wouldn't have, due to the intimidation factor I mentioned earlier. And as a trainer who works in the real world training real people, I tend to think an exercise program is only as good as the client's willingness to comply with it.
So next time you're at the gym and you see a personal trainer setting someone up with a circuit of machine-based exercises, don't assume the trainer is an idiot who doesn't know what the hell she's doing, because there's a reasonable chance the trainer is me. And I am a lot scarier than you are, and you really don't want to be on my bad side. Trust me.