Many bodybuilding coaches swear by free weight training. But are all those wonderful devices in the gym then less effective for muscle growth?

RESEARCH

Based on two recent studies, the answer to that question is no. Both studies – Aerenhouts et al (10 weeks/36 participants, untrained) and Schwanbeck et al (8 weeks/46 participants) – showed equivalent results of training with free weights and with machines – both in terms of muscle growth and strength gain.

How effective an exercise is at developing a particular muscle group depends on the movement pattern and the amount of mechanical tension you can exert with it. Whether you use machines, free weights, cables or your own body weight, it doesn’t matter in that regard.

Coach Menno Henselmans says about this:

Some machines are great. Some suck. We should look at which stimulus a muscle receives. Muscle is just contractile tissue. It doesn’t register how we name the object you have in your hand.

Update 10/14/2021: A new meta-analysis, based on 12 studies, shows that there is no difference between training with machines and with free weights when it comes to muscle growth. Menno Henselmans does, however, place some critical comments on the authors’ conclusion.

Update 7/1/2023: a new study shows that it doesn’t matter if you train with weights or just your body weight. So it’s about the mechanical tension.

TESTOSTERONE

Schwanbeck’s study does show that people who train with free weights have a greater increase in free testosterone. However, this does not appear to make any difference to the final result, the muscle growth.

We actually already knew that: several studies have now shown that the so-called hormonal response during training has no significant influence on muscle growth.

ADVANTAGE FREE WEIGHTS

But why do many coaches advocate training with free weights?

The main advantage of free weight training is that you can create a completely natural movement, targeting multiple muscle groups to not only move the weight, but also stabilize it. Training with machines usually does not provide this advantage, because then you train a muscle group in isolation and you do not use the coordination muscles. Many coaches therefore think that free weight training is indispensable in the long term for developing a complete musculature.

In addition, practice has shown that large compound exercises with free weights – such as the barbell bench press and barbell squat – are extremely effective for muscle growth and strength gain. That’s probably because these exercises disrupt homeostasis (your body’s internal balance) more than other exercises do. And more disruption = more muscle growth.

ADVANTAGE DEVICES

However, there are also devices that can cause this disruption are not or hardly inferior to compounds with free weights. The leg press, for example, as an alternative to the barbell squat. Or some chest press machines, which achieve a greater range of motion (and therefore more stimulus) than bench presses with dumbbells or barbells. And the barbell row has the disadvantage that your lower back has to do a lot of work, while with a machine you can fully focus on your upper back.

Especially the latter seems to be the big advantage of devices: you can isolate muscle groups better, even with some compound exercises.

THE VERDICT

It is evident that for muscle growth you primarily do compound exercises (squat, leg press, deadlift, bench press, barbell row, …) and supplement them with isolating exercises (biceps curl, side raise, …). That way you know for sure that all your muscle groups get enough stimulus.

In principle, it doesn’t seem to matter whether you train (predominantly) with free weights or with machines. But because both training methods each have their own specific benefits, choose a combination of free weights and machines for optimal long-term results.

Researcher and hypertrophy expert Brad Schoenfeld puts it this way:

Both have their place in hypertrophy training. The advantage of free weights (the involvement of stabilizing muscles) is the disadvantage of machines, while the advantage of machines (the focus on individual muscles) is the disadvantage of free weights. But you don’t have to choose at all. Muscle growth actually benefits from a combination of free weights and equipment.

According to bodybuilding coach Mike Israetel, equipment or weights is not a legitimate question. It’s about choosing the exercise that meets your goals. More on that in this video.

In short, choose a ‘smart’ combination of different types of resistance in your training program: free weights (barbells/dumbbells), body weight, cables and equipment. In compound exercises you will generally reach for the free weights more, while you can do isolation exercises with both free weights and machines.

Last updated June 1, 2023