Benefits of using barbells
Some benefits of using/training with a barbell is that it will help improve your overall functional strength, and your overall functional movement (the movement being more natural to what we are used to).
For example the squat; compared to resistance machines where the muscle group is being isolated on either a leg extension (quadriceps) or a leg curl (hamstrings) machine the barbell allows us to complete the compound movement by working our quadriceps and hamstrings together.
The body functions as a complete system and it likes to be trained as a complete system, not broken down and trained in separate muscle groups.
Barbells are a free weight exercise and to move them under load our body will move them the way we are supposed to whereas resistance machine can only move to what fixed way they are made to.
A natural movement of walking up the stairs we use both our quadriceps and hamstrings as they always work together to balance the forces on either side of the knee. "Since they always work together, why should they be exercised separately? Because someone invented a machine that let's us?"
