Defense The free-weight barbell shoulder press is a tried-and-true mass builder with decades of anecdotal reports supporting its effectiveness.
Prosecution The Smith machine allows for a controlled path of motion, as well as safety latches if you get stuck.
■ Free-weight presses require the most help from shoulder stabilizer muscle groups. This helps strengthen hard-to-target muscles, such as the rotator cuff, which can make you stronger and less susceptible to injuries.
■ Free-weight presses also allow for a more natural arc of movement as you press the weight overhead.
■ The Smith machine uses fewer stabilizer muscles; however, the advantage is that the smaller, weaker muscles will not hold back your strength, thus allowing you to lift heavier weight.
■ One unpublished study from the Weider Research Group discovered that when trained bodybuilders did the Smith machine shoulder press, they were, on average, about 15 pounds stronger than when they did the free-weight press.
VERDICT: FREE-WEIGHT BARBELL SHOULDER PRESS
Although you may be able to press more weight on the Smith machine, free-weight exercises allow for the most natural movement patterns and use more stabilizing muscle groups.
Even though the free-weight barbell shoulder press is your go-to mass builder, switch between the two exercises often to get the best of both worlds. After all, using more weight allows you to place greater overload on the deltoids, and that can lead to improved growth. Don’t exclusively use the Smith machine, or your stabilizer muscle groups will suffer, leaving you weaker in the long run and at greater risk for a shoulder injury.