To get
rid of some old myths, free weights do not help to gain more muscle mass than machines, and machines do not provide any additional benefits in terms of “form and definition.”

Let us look at the pros and cons.

• Safety: no difference.
Some machines, such as “cable pulldowns” for the back muscles can be dangerous if they break, and such problems are unlikely to happen using free weights. Inadequate maintenance and wear and tear affect machines more than free weights.
Machines may also be poorly designed, resulting in inadequate execution of the exercise over long periods. On the other hand, the discs used for free weights may be inaccurately calibrated, bars may lack grip notching, or they may be to thick or too thin (ideally they should be about 1 to 11/4 inches).

A machine is usually safer than a free weight if you suddenly run out of strength, or injure yourself midway through
an exercise and you end up dropping the load (e.g., “multipower bench press”) because safety features are
normally in place to prevent these accidents.
Some machines also allow you to pick up and put down the load more safely than the equivalent free weight would.
This is particularly useful in the case of back problems.
• Ease of use: machines
Machines are usually easier to use because they have a fixed travel, making them particularly suitable for beginners.
Meanwhile, advanced users can concentrate on the muscle they wish to train without the risk of losing balance or
the need to train with a companion.
Good technique is essential when training with free weights, although many exercises are very simple.
• Ergonomics: free weights
Machines normally allow numerous adjustments, but even so the individual will always need to adapt in some way.
Free weights adapt to the individual.
The load on a machine is not usually the “actual” weight lifted by the athlete due to the effects of pulleys and levers. In the case of free weights, “what you see is what you get.”
Movements are usually much more natural using free weights than machines.
• Motivation: no difference
Free weights tend to be more motivating than machines, although there is no real reason for this.
Some people dislike having to load up bars, unload them and put the weights away.
• Versatility: free weights
Free weights, and especially dumbbells, are much more versatile than machines.
• Price: free weights
Free weights are much more economical to buy than machines. Because of this, you are more likely to find a gym that is more stocked with free weights than machines.
• Time: machines
It is usually quicker to change the weight selection on a machine, which is very useful if you are sharing an apparatus or want to change the load fast.
• Efficacy: no difference
Machines allow permanent effort, in contrast to some exercises using free weights, where only a part of the movement is made against the force of gravity. Free weights tend to involve the fixed muscles more, an important difference.

Bodybuilders often believe that free weights encourage more growth than machines, but this is a matter that should really be assessed on the basis of the exercise in question. For example, a “standing calf raise” using a bar across the trapezius or under a machine support is exactly the same measured in terms of the effect on the calf muscle.
In contrast, a “preacher bench biceps curl” may be less intense than the equivalent machine, where the strain is constant. It is because of this that “efficacy” is treated as equal in the above paragraphs.