Something you need to keep in mind is that when you exercise, you are training for life. You still may spend an hour a day in the gym, although that will still leave another 23 hours or so for your muscles to function without using any fancy equipment.
Whenever you do any type of exercise, the movement of your body during the exercise is known as the range of motion. The more difficult the range of motion is, the more effective the exercise will be, because your body has to work twice as hard to perform the movement.
Take for the instance the classic dumbbell bicep curl. If you aren't familiar with the exercise, it is performed by standing up straight with your palms facing forward, and a pair of dumbbells held down by your sides. You'll contract your biceps to bring the dumbbells up to your shoulder height, then repeat the exercise as many times as you wish. Using that same movement for exercise on a bicep curl machine, you should sit down, brace your upper arms on a pad, grasp 2 handles that are in front of you, then perform the same movement as above to move the handles in an upward motion.
Now, looking at the muscle contractions in this exercise, you are contracting essentially your biceps if you are using the curl machine, and that is pretty much all you are doing. When you use the machine you are sitting down, which will limit just how much your shoulders give. The machine has several muscles used in this exercise limited to the biceps, as well as the muscles in your forearms and fingers.
Most of the time, when using machine weights, you will always be limited as to what type of exercise you can perform. You must always follow a strict procedure, which is pretty much the same with free weights. Unlike free weights, machine weights offer a certain degree of resistance.
There is a lot of discussion about whether free weights are superior to machine weights. Body builders seem to prefer free weights. They feel the less-restricted range of motion allows them greater liberty in building their bulky muscles. There is also a limitation in the amount of weight on a machine; generally, most machines go up to 250 pounds and most body builders and competitive weight lifters lift far more than that. For building strength and general fitness, however, machine weights are perfectly adequate.
In a nutshell, free weights will use more of your muscles than the machines do, which makes them more effective overall. This doesn't mean that the machines are a waste of use, as they offer some great advantages. In some cases, it is best to stabilize the muscles that are being used in a movement, which is where machines are the best to use.
In the past several years, resistance systems (such as Bowflex) have become very popular. Instead of weights, these use resistance to build muscle and can produce excellent results while taking up very little space. Like the machine weight home gyms, these aren't practical for body builders or competitive weight lifters, but they are a very good alternative for someone who just wants to get into shape and look good.
The decision on which to use for you should be based on what you hope to achieve with lifting weights and where you plan to use the equipment, such as home or at a gym. Both systems are great for your body, although the free weights are best to use if you want the best possible workout, and always ensure that your muscles are getting the right workouts they need.
