First of all, let's talk about the benefits of fixed instruments. Because the trajectory of the instrument is relatively fixed, the movement difficulty is not too high, and it is easy to complete the standard movement. Even if the action is not standard enough, the stimulation to the target muscle will not be too small.

Free equipment includes dumbbells, barbells, etc. When using free equipment for training, it is difficult to complete the training action with the participation of various auxiliary muscles to ensure balance and stability because of the uncertain motion trajectory of the equipment. But it is also an exercise for the trainer himself, which can make the muscles develop in a balanced and all-round way.