A question that not only arises to you, but to most of the people who start in the world of training.
To get a little out of this great doubt I will explain something ..
The natural thing when we start training, is to start with the machines, very logical, why?
The first days of training we must dedicate them to know the technique of the movements that we want to train. Once the correct technique has been learned, we can continue with the progression and move on to freer and multiarticular movements, usually made in free weight, which will make us work in a global way.
Guided machines should be our priority at the beginning of our training, as they help us isolate the muscles and perform a controlled movement. The “disadvantage” of working on machines is that it does not provide us with freedom of movement: the exercise always has the same route and is performed in the same plane, which is usually horizontal or vertical.
Concentration is important in working on machines, since we must be aware of the muscles we are working to activate the correct neuromuscular connections. These will help us recognize the muscles to activate when we perform the same exercise with other means such as pulleys.
The next step will be the training on pulleys, where the movement is still guided, although to a lesser extent. The work on the pulleys requires a good stabilization and allows us to perform exercises in different planes: the most important is the transverse plane, where the rotation movements are performed, which are the most common in our daily life.
Once mastered the technique completely we can move to work in free weight, which is characterized by allowing us to make completely free movements. Training in free weight the stabilization of our body depends solely on us: to perform exercises correctly and safely we must have a strong middle section, since it is responsible for our balance. In addition, working with dumbbells and bars allows us to perform functional and multi-articular exercises in which not isolated muscles, but long muscle chains, much more complex to control participate.
A step further in the progression of difficulty would be to perform the exercise with an element that creates instability, or by removing supports. The use of TRX, bosu, fitball or other similar means implies a total activation of our core to keep us stable while doing the exercises.