Many people are eager to lift weight once starting a fitness program. Care more of what machines for tone up particular muscles group than asking what the body needs or seldom question what impact the exercises impose on the whole body. When we walk or jump, more than one muscle group is working together and move in multi-plane. Movement-based exercise is more beneficial to allow the muscles working with other parts of the body. In other words, we are not training the muscles, but let the body be more efficient to coordinate the movements.
All systems of the body are designed to work together. Muscles function as part of an integrated network to produce and control force through connective tissue which forms the tensional network known as the fascia system. Muscles and joints function in a synergistic relationship with other adjacent muscles. What happens at your ankle will have an effect on your shoulder when the tension passing through all the joints. Different parts of muscle communicate with each other by means of tension. The better the communication throughout the body, the better the function of the body. 
The approach of training body part in isolation does not take advantage of the mechanical forces produced when numerous muscles and fascial structures work together in synergy. Those machines particularly designed to move in a fixed path do not allow us to use our body as we do in the three dimensional world. Like other body pumping exercises, it is designed to focus force into specific muscles for the purpose of developing muscle hypertrophy. The automated lifestyle free us from intensive labor work. However, our joints become more immobile as a result of less active on daily basis, even barely able to stand in extension through our hips after long hours of sitting. The training over focus on isolated muscles will further lead to movement dysfunction.
The primary movements such as lunge, squat, push, pull, rotate, and bend are essential in the first stage of a training to allow the body to move more efficiently in tri-plane movement, to increase communication of the major complexes and to increase the stabilization and mobility of the joints.
As a foundation for integrated movement patterns, ability in performing basic function will carry-over to everyday movements, activities and performance. The results will be extremely effective in achieving variety of goals such as decreased pain, injury or body fat or improvements in fitness and sports performance. (Further reading: Train for movement efficiency)
