Most pieces of gym equipment have at 30x30 Total Transformation least one terrible flaw; they tend to isolate each muscle that is being worked on. This is a little bit like training a basketball team one person at a time and then expecting them to perform as a well oiled unit. Isolating a muscle does not teach it how to work in concert with the rest of the body. As isolated muscles get stronger, connective tissue and stabilizer muscles get weaker, opening the door for injuries and chronic problems. Many injuries occur because of a weak body part, like a weak link in a chain. Common problems are ankle, shoulder, hip, knee and back injuries, ALL of which can be significantly helped with proper training.
Gym equipment does NOT prepare the body to function as nature intended. There are no unbalanced items to carry or lift. If you want to train on an unbalanced surface, you are resigned to a balance disk, which few gyms actually have available. Machines such as the leg extension are terrible for the knee joints, placing stress on the knee from the wrong angles ,which can cause improper movement patterns and lead to injury. Working on machines that isolate the chest muscles allow for no balance or stabilization to be practiced because the move is in a single set plane of motion. (The next time you are laying on your back pressing up the rear end of a car, I guess bench press would be of some use). The body was designed to move over uneven ground with agility and power and to carry unbalanced items like wood, rocks, food, children, etc. and handle adverse conditions.
Although working with parts of the body like stabilizer muscles and connective tissue may seem like it will take more time to reach your goal, it actually provides you with faster gains than isolated movements. This is because when you are out of balance, or working multiple body parts at the same time, your body must work harder to stay in alignment, thus it becomes stronger and leaner at an accelerated rate. In short, you simply burn a lot more calories when you have to work harder. But, it has the added benefit of training the body to function properly in every day situations, helping to reduce the risk of injury.