Several old-school lifters at my gym shun all but the most basic machines in favor of free-weight exercises. What’s your take on machines versus barbells and dumbbells?
ANSWER
Building maximal muscle mass requires a program that emphasizes free weights, particularly multi-joint exercises like squats, bench presses, shoulder presses and rows. These exercises allow you to use more weight. The more weight you can impose on a muscle, the more stress is applied, resulting in greater growth potential. A free-weight movement requires intense resistance by the target muscle as well as myriad stabilizer muscles, thereby building muscle mass in both.
However, I will admit that anyone serious about adding significant muscle must use both free weights and more modern machine equipment for the unique benefits they offer. Taking advantage of both of these tools is the best way to reach your bodybuilding goals.
Machines allow constant tension to be placed on a muscle throughout the range of motion. When you do biceps curls with a barbell, for example, the resistance at the top decreases, due to the fact that free weights rely on gravity. When you do curls in a machine, the resistance is maximal throughout, which means more muscle fibers are overloaded for a longer time.
Another benefit of modern machines has to do with the strength curve of muscles. For example, during a biceps curl, the muscle is weakest at the start, when the arm is fully extended, and gets stronger as the elbow bends to 90 degrees, and then gradually gets weaker from there to full arm flexion. With a free weight, you are limited by how much you can curl at the start of the movement, despite the fact that your muscle is stronger in the halfway position.
Many machines use a cam that changes the tension on the muscle as the range of motion changes. In a biceps machine, the weight on the stack is easiest at the start of the curl, gradually increasing to the halfway point, and then gradually decreasing as the arm moves to full flexion. This puts maximal tension on the muscle fibers all the way through the exercise.
Finally, machines require very little use from stabilizer muscles. This is a drawback if you only use machines. However, bodybuilders can use this to their advantage. When stabilizers are fatigued from free-weight exercises toward the end of a workout, they will limit strength on further free-weight movements, and the target muscle does not get optimal stimulation. By switching to machines at the end of your workout, when the stabilizers are fatigued, you can continue to apply maximal force to the target muscle because the machine takes the stabilizers out of the equation.
Thus, the best way to maximize muscle mass is not by shunning machines like those guys in your gym, but by using all the tools at your disposal.
