Why You're Wrong About Machine Training

Current scientific thinking suggests that muscles get bigger and stronger when they're exposed to unaccustomed levels of tension. The magnitude of that tension is most important for strength goals, and the volume of that tension – the number of times your muscles experience tension per unit of time – matters most for hypertrophy (size) development.

Both machine and free weight exercises expose your muscles to tension, but with slightly different pros and cons. So abandon your ideological thinking and think of both options simply as tools that have varying degrees of utility, depending on context and circumstances. And remember, you're not restricted to one or the other.

By definition, a machine-based exercise is a movement where you're required to exert force against a resistance without needing to do much in the way of controlling that force, at least compared to similar free-weight exercises.

Let's examine two very similar exercises – the Smith machine squat and the barbell squat. They both stimulate the same muscles, but in slightly different ways. Let's examine the pros and cons...

• More technique options. Because the bar slides up and down a fixed rail, you can do a number of things you can't do with a barbell, like placing your feet in front of (instead of directly under) the bar. This strategy allows you to assume a more upright position than you could achieve with a barbell squat, which means greater quadriceps recruitment.
• You can use more weight because you don't need to balance or stabilize. This results in more muscular tension, which in turn equates to more pronounced strength and hypertrophy adaptations.
• The Smith machine is much more forgiving of relatively minor errors such as positioning yourself slightly off-center under the bar.

1. It doesn't require you to control bar path. While this is the most often-cited criticism of machine training, I've never once – in my many years of studying motor unit recruitment – come across the notion that control was a necessary or even a desirable precondition for strength or muscle development. Again, muscle fibers adapt and grow when they're forced to generate high levels of tension. Not only do Smith and barbell squats both afford the ability to provide this tension, in many cases, the Smith squat is a better way to provide this tension.
2. If you only squat on a Smith machine, you'll never learn how to do a proper barbell squat. While undeniably true, I wonder how consequential this really is, assuming that you don't plan to compete in powerlifting. It's much like pointing out that if you only play the piano, you'll never learn to properly play the organ. If the goal is organ mastery, this is a problem. But if the goal is to cultivate more generalized musical skills, it's not.
3. The strength acquired by using free weight exercises has greater positive transfer to many "real world" skills. While we're now at least getting into a more plausible defense of free weights, the concept of transfer is often poorly understood and applied, largely because movement structure is only one component of transfer.

Now, don't get me wrong, movement structure certainly matters. For example, it's intuitively obvious that the strength gained from squatting will positively transfer better to a vertical jump than the strength you'd acquire doing leg extensions, mostly because the structure of a squat is much more similar to a jump than the structure of a leg extension.

However, if you're comparing the positive transfer potentials of Smith and barbell squats, there's really not a whole lot of difference between the two, unless you place your feet considerably in front of the bar when Smith squatting. But even here, the differences are relatively minor.

But does needing to control your muscular efforts during a barbell squat transfer over? While there might be something to this, unless you find the vertical jump to be a complex maneuver (in terms of balance and/or overall body control), I'm far from convinced that barbell squatting would offer a significant advantage over Smith squats.

Of course, if you were serious about improving your jumping skills, simply doing vertical jumps would offer the best opportunity to work on those skills.

If strength or hypertrophy is your training goal, the "best" exercises are those that allow you to safely expose the target muscles to external tensions sufficient enough to trigger adaptation. Sometimes machine exercises are the best option and other times free-weight drills are better.

Thankfully, few of us are limited to only one of these two training options. The intelligent use of both offers greater benefits than restricting yourself to one or the other. A few examples:

1 Leg presses after barbell squats

Sometimes your ability to do more squats will be limited by lower back fatigue, not quadriceps fatigue. Oftentimes, a lifter will need to stop squatting before his quads are optimally stimulated. One simple solution is to move on to leg presses (or hack squats, Smith squats, or even leg extensions) after your low back is too tired to safely permit additional barbell squatting.

2 Triceps pushdowns after bench pressing

For many lifters, benching stimulates the triceps to some degree, but triceps fatigue is rarely what stops you from doing more benching. So it makes sense to follow your bench presses with direct triceps work.

This could be done with free weight exercises of course, but given the relatively high "psychic stress" of heavy benching, it's often more practical and palatable to instead opt for a machine variant such as pushdowns.

3 Leg curls after Romanian deadlifts

Overall, RDLs are arguably a better hamstring exercise than leg curls, but much like with squats, RDL sessions are often terminated by low back fatigue rather than hamstring fatigue.

Also, RDLs train the hammies only as hip extensors, ignoring their other important role as knee flexors. By following RDLs with leg curls (prone or supine), you can do additional hamstring training with no additional lumbar fatigue while also addressing the knee flexion role of the hams.

4 Pull-ups followed by pull-downs

Many lifters and coaches will tell you that pulldowns are inferior to pull-ups, but this is ideological meathead thinking. Sure, striving to improve your pull-up ability is well worth the effort, but assuming you equate loads, the two movements are nearly indistinguishable.

One downside of pull-ups, however, is that you might not be able to do a lot of them (yet). Perhaps a difficult pull-up session for you is bodyweight for 3 sets of 3. While this is an adequate strength stimulus, it only adds up to 9 total reps, which probably isn't enough volume for muscle growth.

This problem is easily solved – move to the lat pulldown machine for a few higher-rep sets.

5 Pec dec after bench presses

Some machine exercises have the unique value of allowing a movement pattern that can't be duplicated through free weights. Leg curls are an obvious example and the pec dec is another.

Sure, presses are a superior pec exercise than the pec dec, but why not take advantage of both? The pec dec allows you to perform isolated horizontal shoulder abduction, something that no free weight exercise can provide.

And since horizontal shoulder abduction is a key function of the pecs, why not follow up your bench presses with some pec decs?

This particular application is beyond dispute: There are many situations where injuries permit machine-training but not free-weight training.

Wrist and hand injuries permit leg pressing or Smith squats when barbell squatting wouldn't be possible. Elbow issues often permit cable crossovers or pec dec when barbell and dumbbell pressing aren't an option.

Low back issues often still permit chest-supported rows, leg extensions, and leg curls when bent rows, squats, and RDLs aren't an option. And, even if you view the machine options as inferior to their free-weight counterparts, I think we'd all agree that machine training is certainly superior to no training.

Many machine exercises require much less time to warm up, set up, and change weights between sets. Personally, I can get through a taxing leg press session much faster (and with considerably less psychic stress) than I could a similarly difficult barbell squat session.

When considering exercise selection, take not only the benefits, but also the costs, into account. If a machine allows you to train a muscle faster or more safely, and/or with less psychic stress, the machine exercise may be the better overall choice, even if it's otherwise slightly less effective.

Free weights and machines have very similar potential when it comes to generalized strength and muscle building. I certainly value the time and effort required to perform well-executed barbell squats, presses, deadlifts, and the Olympic lifts, but these free-weight skills are by no means necessary (or even optimal) to get strong and jacked.

Yes, there's a certain visceral satisfaction inherent with many classic free-weight exercises that machine-based movements simply can't offer. And if you value this unique experience, I'm right there with you. Nonetheless, it's a healthy practice to check our tendency to criticize things we don't enjoy, especially when these critiques aren't based on credible evidence.

Consider that a few years ago, T Nation contributor Mark Rippetoe started promoting the idea of weightlifters doing low-bar squats. He was almost universally mocked by traditional weightlifting coaches. As if putting the bar a few inches lower on your back is going to totally ruin your training.

Is a little perspective too much to ask? And maybe some evidence-based discussion too?