Pros and Cons of Machines and Free Weights

• Free weights allow for truer biomechanical tracking and range of motion of joints, whereas the consideration of these factors while using a machine are sometimes limited to the one-size-fits-all setup allowed by some machines.
• The safety factor is often higher when using machines. For example, being unable to move a machine bench press off your chest is usually not unsafe. However, being unable to move a barbell off your chest without a spotter can endanger your life.
• Speed of movement between weight increases or decreases is usually faster on machines than on barbells or dumbbells. Changing weights on machines often consists of only moving a pin. Changing weights on barbells can entail collar removal, plate exchange, and collar replacement.
• Weight changes with free weights is often smoother, however, than with machines. Barbell plates go down to sizes as small as one-and-a-quarter pounds apiece, which means increments can be as small as two-and-a-half pounds. Increments on some machines are no smaller than five or even ten pounds. A ten pound increment on a small muscle like the biceps can be a very big jump in intensity.
• Machines are easier to learn to use correctly because the body is stabilized by the machine, and all the muscle is forced to do is move the resistance through the range of motion imposed by the mechanism.
• Free weights are more difficult to learn because there are more than just the target muscles being used in free weight exercises. Aside from the muscles moving the weights through their range of motion, there are also other muscles being used to stabilize and control the balance of the body. The benefit of this additional work and awareness is that the use of free weights creates a more "real world" type of feeling from the movement than would a similar exercise on a machine. For example, doing a standing barbell curl mimics the actual experience of lifting a box from your thighs to your shoulders unlike the performance of a curl done on a seated biceps machine.

Tips on getting the most from both free weights and machines:

Many machines have a number of mechanical settings besides the weight load. Often there are:

seat heights

starting or ending range of motion

limb length adjustment, and

incline or decline bench settings.

Check all of these before using the equipment, and adjust them to match your body size and frame as closely as possible. If you are in any doubt about the settings, ask for instructions from one of the trainers in your gym.