What’s better for building muscle and increasing strength: weight machines or free weights? This battle has become one of the most persistent and misunderstood debates inside the gym.
There will never be a winner because most people speak past each other and give their opinions rather than facts; we’re going to do both.
By using research, along with anecdotal evidence, we think there’s a clear answer to this raging argument, and we’re going to name the winner in this article.
Key Points You Need To Know!
Free weights and weight machines are both effective pieces of gym equipment
What’s better for muscle growth and strength is a common debate
Research shows that direct comparisons show both are effective, and there’s no meaningful difference
Strength gains are specific to the training equipment
Nuance still exists when considering long-term training
Gym Equipment: Free Weights And Weight Machines
Free weights and weight machines are two primary pieces of gym equipment used to build muscle and increase strength.
The more basic of the two, free weights, have been around ever since people first engaged in weight training. Barbells and weight plates were the primary method of training for not just strength athletes, but were the preferred training method during the Golden Age of bodybuilding.
In the 1970s, weight machines came onto the scene. However, it was the rise of commercial gyms in the 1980s that really blew up their popularity.
What Are Free Weights?
Free weights are independent weights that can move “freely” through space. This includes;
Barbells
Dumbbells
Weight plates
For the sake of this article, we won’t be referring to kettlebells or other forms of unconventional training such as sleds and tire flips. We love these, but generally the debate is focused on barbells and dumbbells.
Benefits
Easier to modify and increase the load (ideal for progressive overload)
Allows greater variation of movements and replicates more movement patterns
Able to simulate movement patterns more naturally
No adjustments needed for different bodies, as the person can simply modify the movement
Can replicate real-world demand due to the stability demand
What Are Weight Machines?
Weight machines are pieces of gym equipment built to mimic specific movement patterns. As such, the weight will move on a fixed path, meaning a lifter just pushes or pulls the load.
Due to the fixed path, stabilizer muscles are not involved to the same extent as with free weights. Common examples are:
Hammer row
Chest press
Leg press
When we talk about weight machines, we’re not necessarily speaking about the cable machine.
We love using cable exercises and think they’re ideal for accessory and smaller hypertrophy exercises. However, they lie somewhere in the middle of free weights and weight machines.
It’s not a weight machine as there’s still considerable freedom in movement.
It’s not free weights, as it still must move in line with the cable.
We’re also not specifically referring to other equipment for the same reason:
T-Bar Row
Landmine Exercise
Belt Squat
Anything similar
However, we can’t necessarily say these aren’t used in the research we cite. They are large metas done, which use a ton of other studies.
In terms of the Smith Machine vs Free Weights for mass and strength, we have a specific article here as well as a Smith Machine Only Hypertrophy Program.
Benefits Of Weight Machines
Lower barrier to entry and easier to use
Safer to use (this can be important for training past failure)
Easier to isolate the intended muscle, even with compound movements
Weight Machines Vs Free Weights: Muscle Growth?
Key Points You Need To Know!
Weight machines and free weights generally result in similar gains in total mass when volume is equated for
Weight machines can possibly isolate the muscle more effectively and produce greater local or regional hypertrophy
Free weights involve stabilizer muscles, resulting in muscle hypertrophy spread over more mass
To fully settle this debate, we’re looking at muscle growth and strength gains separately. First up, muscle growth.
Each method has reasoning for why it might be better, and ironically, it pertains to the same mechanism.
Free Weights claim to be superior for muscle growth due to the use of stabilizer muscles. These muscles add to the total muscle mass worked, which theoretically results in more muscle growth.
Weight Machines suggest that because the stabilizer muscles are taken away, it allows greater isolation of the intended muscle. Further, because less muscle mass is involved, it mitigates the risk of accessory muscles being fatigued before the primary muscle is fully trained.
What The Research Says
Research suggests they might both be right.
There have been several metas now, and when volume is equated for, there is no meaningful difference between muscle growth (Haugen et al., 2023; Schwanbeck et al., 2020).
In other words, free weights and weight machines can both effectively build muscle. However, the muscle growth isn’t necessarily equal across the same muscles.
Remember, above, we discussed the stabilizer muscles; this is where they may both be right.
Free Weights can potentially result in hypertrophy occurring across a greater area of muscle mass.
Weight Machines can potentially result in more hypertrophy occurring in a specific muscle; this is referred to as “localized hypertrophy”.
Imagine 2 lifters train bench press and chest press for one month using the same volume. At the end, both lifters add 1lb of muscle mass.
The Free Weight Lifter has 1lb spread evenly across his shoulders, triceps, and chest.
The Weight Machine (Chest Press) Lifter has .9 pound spread access to his triceps and chest, and just .1lb across his shoulders.
To be clear, these proportions are made up for illustration purposes. However, you can see how they both gained the same amount of total mass, but it’s distributed differently.
Free Weights Vs. Weight Machines For Muscle: Other Considerations
So when volume is accounted for, muscle growth is essentially the same. With that said, there are some other considerations.
Free Weights Allow More Exercises, Variations, and Angles. Above, we saw that using machines can possibly result in greater localized hypertrophy. Keeping that in mind, using free weights tends to allow greater variation in the long term.
Using different angles for bench press
Changing grip width is easier
Performing moves like drag curls and spider curls is easier
This is important because research shows that muscle growth does not occur in a uniform manner; this means the part of the muscle that experiences greater load sees greater growth.
As a result, research suggests exercise variation in a systematic manner is ideal for muscle hypertrophy (Antonio, 2000).
Weight Machines May Be Better For Solo Lifters. A bit nuanced, but solo lifting can be intimidating or challenging when training with intensity.
Training to failure is risky
Harder to use assisted reps
Changing weights for drop sets
Weight machines solve all these issues.
Weight Machines Vs Free Weights: Strength Gains
Key Points You Need To Know!
Free weights and weight machines result in similar increases in dynamic strength
All strength training is effective, but the modality you use increases strength more specifically to that modality
Free weights are likely ideal for “real-world” strength
Choosing free weights or weight machines for strength gains is a bit more nuanced.
Unlike muscle hypertrophy, the general consensus has always been that free weights are superior for muscle growth.
Muscle strength is an expression of performance, and free weights require greater stabilization. Therefore, coaches and lifters theorize that true strength in the real world requires greater stabilization, making them the better choice.
What The Research Says
This actually surprised us somewhat.
The latest research shows that essentially there is no difference in maximal strength gains with free weights and weight machines. However, the choice of equipment can make a difference.
When testing gains in dynamic strength: Free weights and weight machines are equal
When testing strength gains on free weight exercise: Training with free weights is superior
When testing strength gains on weight machines: Weight machines are superior
This simply means that free weights and weight machines have similar effects on overall strength. However, when comparing the effect they have on each other, strength improvements are specific to the equipment you use.
For most people, the nuance isn’t really important, and you can use what you feel comfortable with.
However, lifters who are training for a specific sport or purpose should choose the gym equipment that replicates their needs.
It’s not completely surprising, as it follows the SAID principle: Specific Adaptation to Imposed Demands. This simply means your body will adapt to the demands placed on it (Kraemer & Ratamess, 2004).
Free Weights Vs. Weight Machines For Strength: Other Considerations
Similar to hypertrophy, there are some unique considerations.
1. Free Weights Allow Power Movements. This includes your obvious power movements like the clean and snatch. In addition, it includes movements like the push press and power rows.
2. Free Weights Can Use Greater Loads. While not absolute, free weights generally allow heavier loads than their weight machine counterpart; this is especially true for upper body exercises.
For some people, this may not be an issue. However, advanced athletes will likely need to use free weights for movements like the bench press and rows.
Keep in mind that this problem is mitigated if you have access to plate-loaded weight machines.
3. Free Weights Are Likely Ideal For Functional Strength. As previously mentioned, strength training is specific to the modality used. While the studies didn’t look at this specifically, we think it’s safe to assume this means “free weight strength” would translate better to the real world.
4. Free Weights Allow Dynamic Movements. While a bit out of context, free weights allow dynamic movements such as farmer carries and sled pushes. This is impossible with weight machines.
So while this is not part of the specific argument, it does shed light on overall differences.
Weight Machines Vs Free Weights: What Should You Use?
With all this in mind, what should you use for training, which is better?
If you’re a general lifter and have no specific goals, use whatever you feel comfortable with.
If you’re trying to optimize your training, here is what we would suggest:
Strength Training: Free weights will ultimately be the superior option long-term
Hypertrophy Training: Use a mixture of free weights, machines, and the cable machine
The most important lesson from all this is that the debate on the best exercise equipment is overblown and generally highly contextual. Both work and both have niche benefits.
We know that some people prefer using weight machines for a variety of reasons; safety concerns, previous injury, or it’s just their preference.
That’s why we’ve created a Smith Machine and Cable Exercise Hypertrophy program. If you want something new or a break from free weights, check it out!
We do believe the best option is to use all the tools available to you. Free weights, weight machines, calisthenics, cable machines, sleds; they all have specific benefits, so it makes sense to include elements of them all.
Let’s keep in mind that we aim to train over our lifetime; that’s a lot of time to use new equipment.
FAQ: Free Weights Vs. Weight Machines: What’s Best For Building Muscle And Strength Gains?
1. Are free weights better than machines for building muscle?
No. When training volume is the same, both free weights and machines can build muscle effectively. The main difference is in how the muscle is distributed. Free weights usually work more total muscle, including stabilizers, while machines can help target specific muscles for growth.
2. Do free weights build more strength than machines?
Not necessarily. Research shows that overall strength gains are similar for both. However, strength depends on how you train. If you use free weights, you’ll get stronger at those movements, and the same goes for machines. This is known as the Specific Adaptation to Imposed Demands (SAID) principle.
3. Why do free weights feel harder than machines?
Free weights require more stabilization and coordination. You’re not just moving the weight; you’re also controlling it through space, which uses more muscles and increases the overall challenge.
4. Are machines safer than free weights?
Generally, yes. Machines guide your movement and reduce the need for stabilization, which lowers the risk of technical mistakes, especially when training to failure or for beginners. Still, free weights are safe if you use proper technique.
5. Should you use machines or free weights in your workout?
The best approach is to use both. Try free weights for compound lifts and building overall strength, and use machines for isolation exercises, training to failure, or focusing on specific muscles.
References
American College of Sports Medicine (2009). American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Medicine and science in sports and exercise, 41(3), 687–708. https://doi.org/10.1249/MSS.0b013e3181915670
Kraemer, W. J., & Ratamess, N. A. (2004). Fundamentals of resistance training: progression and exercise prescription. Medicine and science in sports and exercise, 36(4), 674–688. https://doi.org/10.1249/01.mss.0000121945.36635.61
Haugen, M. E., Vårvik, F. T., Larsen, S., Haugen, A. S., van den Tillaar, R., & Bjørnsen, T. (2023). Effect of free-weight vs. machine-based strength training on maximal strength, hypertrophy and jump performance – a systematic review and meta-analysis. BMC sports science, medicine & rehabilitation, 15(1), 103. https://doi.org/10.1186/s13102-023-00713-4
Schwanbeck, S. R., Cornish, S. M., Barss, T., & Chilibeck, P. D. (2020). Effects of Training With Free Weights Versus Machines on Muscle Mass, Strength, Free Testosterone, and Free Cortisol Levels. Journal of strength and conditioning research, 34(7), 1851–1859. https://doi.org/10.1519/JSC.0000000000003349
