The discussion as to whether free weights are more or less effective than resistance machines has raged on for years now, with the accepted wisdom being that whilst free weights are better for muscle growth, machines are safer and more accessible.
Probably the most famous recent study to look into this is the one by Shaner et al (2014) that compared barbell squats to the leg press.
The study found that barbell squats produced greater results in total work, strength, and produced a greater hormonal response .
This article will take a look at the benefits and negatives of each to discover which is best. [toc]
The Difference Between Free Weights And Machines
You will find that most gyms will have a good selection of machines, along with a dedicated free weights area.
There will also be plenty of treadmills and other cardio equipment, but we are not here to discuss these here.
Free weights include dumbbells and barbells. They also include kettlebells and anything else that you have to pick up and hold.
They work by increasing the resistance against gravity. With the heavier weight being harder to pick up and manoeuvre.
When using free weights you may need to use additional equipment, for example, a bench for bench pressing, or a cage for squatting.
Machines on the other hand only work through a specific range of motion.
When using a machine you will typically be sitting in or on it. The leg extension and chest press machine are two common machines you would find in your local gym.
There are also cable machines, which may be machines, but work in a similar fashion to free weights as you are not stuck using a specific range of motion.
Are Free Weights Or Machines Safer?
Whilst this may seem to be the most important aspect of the debate, it is important to discuss this in the proper context. Because both free weight and resistance machine exercises are significantly safer than most exercises, particularly running and competitive sports .
In Bret Contreras’ article on the subject, he states that free weight exercises have higher rates of acute injury whilst machine exercises have higher rates of chronic injury . But as mentioned before, the injury rates for both are so low that it hardly bears mentioning.
Perform either with excellent form, and patience and you will remain injury-free.
Are Free Weights Or Machines Easier?
If you don’t know what you are doing in the gym then machines are probably a safer bet for you.
You don’t want to arrive at the gym for your first session, grab a barbell and immediately hurt your back, do you?
Good form while lifting free weights is incredibly important to avoid injury. So until you learn the proper technique it is best to stick to the machines.
Do Free Weights Or Machines Work The Nervous System More?
Not often talked about, but the nervous system has a crucial role in strength training.
In his article on machines versus free weights, McBride states that free weight exercises stimulate the nervous system more, which would lead to lifters being able to lift heavier weights .
Will Free Weights Or Machines Promote More Hormonal Response?
In the previously mentioned study by Shaner et al (2014) they not only looked at the strength response of free weights compared to machine weights, they also looked at the hormonal response.
They found that free weights increased Human Growth Hormone (HGH) and Testosterone (T) significantly more than machine weights.
Another study by Budnar et al (2014) found that kettlebell swings also increased testosterone and HGH .
So why is the hormonal response to exercise important? Basically, because testosterone and HGH can improve strength  increase muscle protein synthesis  and help increase muscle hypertrophy.
Which Of The Two Is More Convenient?
If you go to the gym at certain times of the day you may struggle to even get into the free weights section, never mind use the equipment you want to use.
Chances are though the machines are a little less busy.
Do Free Weights Or Machines Cause More Muscle Activity?
Another thing to look at is how many muscle fibres are recruited during an exercise, more muscle activity per exercise leads to more strength and hypertrophy increases.
Schick et al (2010) found that there was improved muscle activation during the bench press when compared to the Smith Machine .
Another study by McCaw & Friday (1994) produced similar results  whilst a study looking into the difference in muscle activation in free weights squats compared to Smith machine squats also found in favour of the free weight version .
Will Free Weights Or Machines Build More Strength And Power?
Finally, we will be comparing the effects of free weights and machines on strength and power.
Jones et al (2008) found that maximum strength and average power were significantly higher during free weight power cleans when compared to machine power cleans .
In a study comparing fixed resistance machines (FR) and free-form (FF) resistance equipment, it was found that FF improved strength 58% more than FR and improved balance 196%. FF participants also reported lower overall pain levels compared to FR .
In Conclusion: Are Free Weights Or Machines Better?
So when looking at the evidence it becomes clear that there is only one winner when comparing the two, free weights have an improved effect on the nervous system, produce a greater hormonal response, produce increased muscle activity, and significantly improve strength and power compared to machines.
But why must your program have an either/or mentality? Yes, there are more advantages to training with free weights but that doesn’t mean that combining the two won’t produce superior results.
If there is one takeaway from this article it should be that you mustn’t prioritise machines over free weights. But look for ways to incorporate some machine exercises into your free-weight strength program.
0 thoughts on “Free Weights Vs Machines For Muscle Growth”
I prefer free weights to machines, but I sometimes use the leg press since my squat isnt the best.
Personally prefer free weights to machines, but imo who cares? As long as you are seeing results then use what you are comfortable with.