Skip to main content

Machines vs. Free Weights: More Research is Needed

The machines versus free weights debate has literally been going on for decades. Certain key figures that spearheaded this controversy, such as Arthur Jones, didn’t do a good job of representing this debate as his knowledge of sports science was insufficient. He was biased as the inventor of Nautilus and his arguments were rife with biomechanical error. I still believe that Arthur was great for the progression of our field (click HERE to read about his methods and beliefs) in many ways. Nevertheless, this debate is a legitimate debate, and the field of sports science has NEVER conducted a proper study to examine this question.

And to me, this is one of the most important studies that we as an industry should be focused on right now as the ramifications are huge. For years, I’ve listen to my colleagues blast machines, stating that they’re far inferior to free weights for purposes of inducing hypertrophic, strength, functional, and sport performance adaptations. I personally call bullshit on this entire premise (as I discussed from 10:30 – 15:55 in our recent podcast).

leg press

As I discussed in my Leg Press vs. Squat: The Final Chapter article, squats appear superior to leg presses, but both could be utilized for optimal results. However, this is besides the point. Squats utilize more musculature, stress more joints, and represent a more functional movement pattern compared to leg presses. So if you compare squats to leg presses, leg extensions, or leg curls, of course squats come out ahead for most purposes. However, if you compare squats to a lever machine squat, such as Tuff Stuff’s, then that’s a different story. They’re very similar in muscle activation and joint moments, but the machine is a bit more stable than the free-weight version (which could be an advantage of a disadvantage depending on how you look at it).

lever squat

Here are the pros and cons of free weight and machine training:

Free Weight Advantages

  1. Less stable (less degrees of freedom) = more stability function (proprioception, balance, sensorimotor coordination, etc.)
  2. Way more affordable
  3. Portable and takes up less space
  4. Have natural bar paths
  5. Represent more natural movement patterns compared to many machines (ex: leg press, leg extension, leg curl) – they better replicate real life movement
  6. More specific to powerlifting and Olympic weightlifting
  7. Work well in concordance with bands and chains (accommodating resistance)
  8. More versatile, provide for plenty of variation
  9. Well suited for maximizing spinal strength and stability
  10. Better suited for lower body ballistics (ex: jump squats)
  11. Better suited for complex, highly integrated lifts
  12. Barbell exercises can be more metabolically demanding
  13. Seem to transfer better to machines compared to how machines transfer to free weight strength

Machine Advantages

  1. More stable = more prime mover activation
  2. Easier to learn (easier to stabilize) and more comfortable for certain lifters
  3. Can use to groove unique motor patterns (ex: smith machine for more upright squat)
  4. Fixed bar paths can prevent acute injury subsequent to lack of stabilization
  5. Certain machines maintain more constant tension on the muscles by utilizing variable resistance (ex: CAMs, plate-loaded, etc.)
  6. Can take spinal stability out of the equation to focus on the legs (ex: leg press, lying squat)
  7. Can be performed after heavy barbell lifts when stabilizers are fatigued to further tax the prime movers
  8. Better suited for targeted, more isolative lifts
  9. Well suited for initial stage rehabiliation
  10. Well suited for training the elderly
  11. Well suited for training beginners who lack confidence in free weights
  12. No spotters required
  13. Are self-contained (no additional equipment required)
  14. Isokinetic dynamometers are well suited for data collection and eccentric or isometric training
  15. The smith machine can be used for ballistics (ex: bench throws)
  16. Better suited for circuit training

Free Weight Disadvantages

  1. Certain lifts are awkward for certain body types
  2. Higher rates of acute injury
  3. Some lifters learn to rely on excessive momentum
  4. More correlated with sloppy form and contorting the body to accomplish a lift
  5. Many lifts have torque-angle curves and strength curves that stress a particular ROM but lighten up at the opposite ROM (ex: squats, good mornings)
  6. Certain lifts require spotters or rack supports
  7. Not always well suited for rotary and lateral vector movements
  8. Loading and unloading plates is cumbersome for strong lifters

Machine Disadvantages

  1. Certain machines don’t feel comfortable for certain body types
  2. Can have unnatural paths which can lead to pattern overload
  3. Higher rates of chronic injury
  4. Costlier to purchase and for maintenance
  5. Not always portable and takes up more space
  6. Less variety and versatility
  7. Aren’t always well-suited for particularly tall or short lifters
  8. Can lend themselves more to left/right imbalances
  9. Often weight stacks don’t accommodate advanced individuals

But it All Depends on the Machine…

As I mentioned previously, it all depends on the machine. A lever squat and hammer strength squat-lunge machine are very similar to the barbell counterparts. I’ve tested the muscle activation in both and the lever variations actually produced higher activation in certain primary muscles.

Hammer strength deadlift

Power squat

Lever lunge

Pendulum quadruped hip extension

Reverse hyper

With These Five Lifts, I Could Produce Better Lower Body Results than 98% of Trainers

Using just these five machine exercises, I bet that I could produce superior lower body hypertrophic and explosive power results to those of the vast majority of trainers just by teaching solid form and relying on optimal program design skills. Kinda blows the whole machines are inferior mantra out of the water, right (assuming I’m correct about my statement)?

Calling All Sports Science Students

I get emails all the time from students in sports science who are seeking a topic of study for their thesis. Well, here you go! This would be a landmark study that would be referenced many times over for years to come. It would go a long way in helping to settle the debate between free weights and machines. But you need to do the study justice. Hopefully some student out there has a great laboratory for testing and a great gym facility for training, which offers free weights along with the hammer strength squat lunge and a power squat (and more).

Sample Study Design

This could actually be an entire PhD thesis that could involve cross-sectional studies involving analysis such as EMG, joint moment, or perhaps force plates if you got creative, with a longitudinal training study to culminate the project. However, it could also just be a standalone study. Here are my thoughts:


  • 2 groups of ten male lifters with at least 3 years of training experience. 
  • Group one performs barbell exercises
  • Group two performs machine exercises

Study Duration:

  • 12 weeks

Prestesting and Posttesting:

Could involve any of the following:

  • countermovement jump height,
  • countermovement jump peak power (would require force plate),
  • broad jump distance,
  • 20 meter sprint time,
  • body mass,
  • body composition,
  • muscle size (would need MRI),
  • strength (perhaps on exercises not involved in the study so neither group has an advantage, perhaps isometric measures using a force plate)

Training Intervention: 

  • Both groups train 3 days/week. 
  • Group one performs barbell back squats, barbell RDLs, barbell deadlifts, barbell reverse lunges, barbell hip thrusts, barbell bench press, barbell incline press, and barbell bent over rows
  • Group two performs lever squats, hammer strength RDLs, hammer strength deadlifts, lever reverse lunges, cable pull-throughs, hammer strength chest press, hammer strength incline press, hammer strength bent over rows
  • Daily undulating periodization is utilized so that 3 sets of 6-8 reps are performed on Monday, 3 sets of 8-10 reps are performed on Wednesday, and 3 sets of 4-6 reps are performed on Friday
  • Monday and Friday involves back squats (and lever squats), RDLs (and hammer strength RDLs), bench press (and hammer strength chest press), and bent over rows (and hammer strength bent over rows)
  • Wednesday involves reverse lunges (and lever reverse lunges), incline press (and hammer strength incline press), and hip thrusts (and cable-pull throughs)
  • Progressive overload is utilized

Be Sure to Measure Hypertrophic, Strength, and Performance Adaptations, along with Injuries

As you can see, I included a wide variety of data which will help answer a lot of questions. I suppose you could add in a power component if you wanted – power cleans versus the power trainer, jump squats versus the bear, etc. (see Powernetics as they have some cool looking power machines).

Power Trainer

I Will Help You!

I would love to be an author on the paper so I’d be happy to help out!


Yes, doing squats will produce better hypertrophic and vertical jump results compared to just doing leg extensions or leg presses. However, what if free weights were pitted against plate-loaded lever machines? Then what would happen? Machines represent an entire continuum, with more isolative movements on one end and more integrative movements on the other end. Which would be superior for hypertrophic gains? What about gains in jumping and sprinting? How big would the differences be – marginal or huge? Which is safer?

Regarding hypertrophy training, would adding leg extensions to a squat protocol add or detract from gains in quad mass, and would adding leg curls to a deadlift protocol add or detract from gains in hamstring mass? Are isolation movements not well-suited for inducing high levels of metabolic stress? Keep in mind that seated leg curls have been shown to increase hamstring flexibility to the same extent as static stretching of the hamstrings, but they likely did so via increasing muscle length rather than increasing stretch-tolerance, and leg extensions have been shown to occlude the distal quadriceps and produce significant hypoxia during sets taken to failure. Can these exercises then be utilized to impose specific adaptations depending on the goal?

Until proper studies are conducted, all we can do is speculate, and nobody really knows the answer. Please check out the research below to help you formulate your opinion.

Some Links to Existing Research

Here is some existing research on free weights versus machines:

Roundtable Discussion: Machines Versus Free Weights – linked to pdf – check out Carpinelli and Stone’s arguments – amazing discussion with lots of references to pull up

Training-specific muscle architecture adaptation after 5-wk training in athletes – this is the best training study IMO

A Comparison of Two Methods of raining on the Development of Muscular Strength and Endurance – this is the worst IMO – WTF is rhythmic isometric exercise haha?

The Effect of Variable Resistance and Free-Weight Training Programs on Strength and Vertical Jump

Hot Topics: Machine Versus Free Weights – pdf is linked

Comparison of muscle force production using the Smith machine and free weights for bench press and squat exercises

A kinetic and electromyographic comparison of the standing cable press and bench press

Specificity of training modalities on upper-body one repetition maximum performance: free weights vs. hammer strength equipment

A comparison of muscle activation between a Smith machine and free weight bench press

A comparison of muscle activity between a free weight and machine bench press – pdf linked

Kinetic comparison of free weight and machine power cleans

A comparison of free weight squat to Smith machine squat using electromyography

Strength outcomes in fixed versus free-form resistance equipment

Comparison of chain- and plate-loaded bench press training on strength, joint pain, and muscle soreness in Division II baseball players

A Comparison of the Effects of Three Strength Training Programs on Women

Strength Training Modes Free Weight-Part II: Considerations in Gaining A Strength-Power Training Effect (Machines vs. Free Weights)

A comparison of the kinematics, kinetics and muscle activity between pneumatic and free weight resistance

A biomechanical evaluation of resistance: fundamental concepts for training and sports performance

The Effects of Training with Free Weights or Machines on Muscle Mass, Strength,
and Testosterone and Cortisol Levels – master’s thesis

Comparison of muscle force production for the smith machine and free weight modes using similar exercises – master’s thesis

A Comparison of Muscle Activity during Free Motion versus Fixed Resistance Exercises – Case study by manufacturers but good researcher (Rhea)

Glutes to the Max – not published by good researcher (Porcari)

Muscle activation during lower body resistance training

Hamstring activation during lower body resistance training exercises

Do single joint exercises enhance physical fitness?


  • Wow! Great article Bret. Lots of research and thought put into it.

    It makes sense to me that using free weights primarily with machines as supplemental lifts would produce the best results.

  • Chris Hynes says:

    I’m in the Scottsdale area if you need some guinea pigs.

  • John says:

    I wonder if a crossover design might be possible in this type of study. It might permit both genders to be included (since each individual can act as a control) and it would increase the statistical power. The participants would be randomized as to which methodology they did first, and assessments would be performed before the study, at the crossover, and after the study. In this case, the outcome could be which method produced the greatest rate of change. You might need to look at “training age” as a confounder, and build it into the subject treatment assignment since newbie gains would be seen in the first arm, and if that wasn’t balanced in the experiment design it would complicate the analysis. I hope someone takes up your challenge (I’m out of school, myself.)

  • Marcus Beasley says:

    Hi Bret, says high bar and the lever squats stress the similar muscles including the core

  • Nate says:

    Bret, wow, what an article. You’ve really got me thinking about using machines again:-). Thanks for the work you’ve put into this article, obviously something that’s been brewing for a while. It seems that the main issue, with all the pros and cons of both machines and free weights is the end result: what are you trying to accomplish with your training? While “different strokes for different folks” might be applicable here, it’s more of the “whatever it takes” mentality that’s needed when evaluating what you need in your training. Thanks again!

  • Great topic Bret. I’m not sure why there is such a big deal over machines and free weights. Each have there purpose and relevant pluses and minuses in terms of usage.

    People should just get used to the idea that both have their place in the training world and should be just considered as tools to help reach an objective. Depending on ones goals and body type why is it necessary to say that anyone is any less important than the other.

    Free weights in my own personal opinion are superior, but some machines do have significant training effects, especially for the populations mentioned in your article.

    Great job Brett. When you get your doctorate I want to be the overtrained military lab rat.



  • Alex says:


    I’ve been thinking about this topic alot lately (but I am not in the industry). My intuition says that free weights blast the nervous system and increase strength, and that machines blast muscle hypertrophy. Can I publish my intuition?.

    To me, it would seem that a program designed around both would allow strength, and hypertrophy, while at the same time allowing the CNS to r&r. I don’t know what the program would look like- maybe 2 weeks free weights, 1 week machines; And maybe trainees can avoid the need of ‘deload’ periods.

    Like you point out, we have no research to back this up.

  • Fred W says:

    Solid post as always Bret. I think if Louie Simmons can say there is a role in training for machines, many can benefit from them provided the programming is done correctly.

    Don’t know if this will get answered since its outside the scope, but I’m curious.

    For an independent small gym owner who only has a free motion machine at the moment which machine of those mentioned above would you add next to the floor space?

    My thought is the Rev Hyp as it can be used in a few different ways.

    All the same thanks for all the articles encouraging people to think. Need more out there like this.

  • Matt says:

    Solid info, but the problem is you can still refute the majority of “Machine Advantages” and call BS on why they could actually be disadvantages, which essentially means machines only have a couple benefits.

    Machines isolating a muscle, not having spinal stabilization in the equation, further taxing the prime movers when the stabilizers are fatigued, fixed bar path, etc. All of these have little transfer of skill, will develop muscle imbalance, contribute to poor posture, build poor unrealistic motor patterns, and in the long run can trash your body’s movement patterns because its such an unrealistic movement. Smith machine for ballistics isn’t an advantage when there are countless better variations that you can do with balls, external loads, and your own body weight.
    No spotter required? have you seen anyone exercise using machines? Tons of people still use terrible form and mechanics, have poor posture and don’t know what they are doing.
    Easier for circuits? I call BS on that one for sure. Your own body is the easiest “machine” to do a circuit workout with, a suspension trainer like the TRX, or a squat rack/jungle gym rack with attachments, even a range of dumbbells are far more easier for a circuit. Whereas machines youre setting pins, adjustments, weight plates, etc and wasting your time generally getting less effective of a workout, especially for those who are using seated machines, and then resting while sitting. Prolonged sitting ruins a persons mobility and athletic potential, and you have most people doing their entire workout that way. Machines are such a waste of money for a gym as well.

    Your hypothesis is fairly interesting and the machines you suggest are better machines than the traditional ones we see, but there is still no research to back it, even if successful it needs to be completed without bias and duplicated multiple times whereas they are countless research studies, and just the eye test that natural movement and free weight movements are superior thus far.

    I’ll still support someone who can actually move their body and an external weight in space efficiently, over someone who can move a heavy load in a fixed controlled unnatural environment anyday.

  • Alex says:

    My glutes have never gotten very strong even in High School squatting/DL 300+ lbs or doing 950 lbs on the leg press my first two years of college, i switched due to issues from squat/dl affecting previous knee injuries. Is it because machines work the glutes less? Is there any exercises(other than squat/dl) I can do that will work my glutes? When I do legs, they seem very disproportionate. My quads get very large very quick, hamstrings show decent growth but glutes always seem to stay the same.

    I’ve just had back surgery(herniation caused by squatting – good form, light, warmup weight) so I will never do squat or deadlift again but need to improve my glutes(both in their flexibility and strength as this was a large factor in what caused the injury)

  • Jeff says:

    I would sub glute bridges for Pendulum quadruped hip extension. I’m not so sure about that one, but I don’t suppose glute bridges would really be a machine based exercise.

  • Charles Nankin says:

    from the videos here i came across videos for Reverse Hack Squats – glory be!

    re machines, i am sure if you get the angles right you can generate a helluva activation, principally because you are stabilised.

  • Franklin says:

    I know this is out of topic, but on a fixed plate loader machine like a leg press or a shrug/lunge hammer strength, on one side i put one 45lbs and othe zero, what efferct would that have on the body?. Is there a rule that states that a machine shouldn’t be used this way?

  • Eddie G says:

    Hi. Nice post and very useful as usual. Please allow me to suggest a small correction. Degrees of freedom is a well defined physics concept, and you can think at it as the number of variables you need to define the position of an object. For instance the bar of a Smith machine has 1 degree of freedom, because you can describe perfectly well where the bar is with only one quantity, the high of the bar (provided that you know where the machine is) and consequently you can only move the bar up and down along a vertical path. However if you hold a dumbbell in your arm (like, e.g. in a dumbbell shoulder press) it is not enough with the high of the dumbbell above the ground, because you can also move the dumbbell forward/backward or left/right, so you need 3 quantities, hence 3 degrees of freedom.

    So, free weights have more degrees of freedom, whereas machines have less. Just the opposite as your first sentence under “Free Weight Advantages”, “Less stable (less degrees of freedom)” – No, it is just the opposite: Less stable (MORE degrees of freedom). The more stable a weight is (i.e. using Nautilus-alike machines) the less degrees of freedom the machine allows, and that is why less stabilization muscles are needed.


  • Eddie G says:

    (feel free to do the correction suggested but not post my comment if you feel embarrassed or something, as well as this one – also if you want to be sure, you may want to check Good luck.

Leave a Reply


and receive my FREE Lower Body Progressions eBook!

You have Successfully Subscribed!