Lorado / Getty
Lorado / Getty
FACTS OF THE CASE
Barbell Squat: Stand on your shoulders with a barbell and drop your feet about shoulder-width apart. Keep the natural arch in your lower back and keep your head facing forward. Bend your knees and hips and let your buttocks muscles run backwards to lower you. When your thighs are parallel to the ground, reverse the direction and drive powerfully through your heels into a standing position. Repeat for repetitions.
Smith Machine Squat: Imagine a Smith machine with shoulder-width stand and rod over your shoulders and traps. Hold your head with a high chest forward and hold the bow in your back. Bend your knees and hips as if you were leaning back until your thighs are parallel to the floor. Repeat the movement by riding through your heels and pressing your hips forward to return to the starting position. Repeat for repetitions.
One major difference between the Barbell Squat and the Smith Machine Squat is how far you can bring your feet forward. With the barbell there is only one position ̵
In 2002, the Journal of Strength and Conditioning Research reported that the farther the feet are positioned in front of the Smith machine bar, the lower the quad participation and the greater the involvement in thighs and buttocks. When the feet were directly under the bar, the hamstrings and gluteal muscles were barely emphasized, while the quads received almost the entire focus. When the feet were about 30 cm in front, the quads and ham / buttocks were stressed fairly evenly. When the feet were set to about 18 inches, the ham and gluteal muscles received the greatest emphasis, the quads were given only a slight emphasis.
Another difference between the barbell squat and the Smith machine squat is its strength. Researchers from Drake University reported that 32 trained lifters tested their maximum repetition rate for the Smith machine squat, which was about five percent stronger than the free-weight squat. Researchers suggested that Smith Smith's ability to increase strength could be due to the decreased balance, allowing for a targeted straightening effort.
THE VERDICT: BOTH
Both exercises should be included in leg training. Although the Smith machine squat has been shown to allow for greater training and forward adjustment of foot positioning, the solid nature of the Smith machine does not require many stabilizer muscles. Over time, this can reduce strength and even increase the risk of injury. In addition to barbell squats, the Smith version of the knee bump allows you to train more intensively and, in addition to barbell squats, first squat in your leg workout and follow them with the Smith machine version after barbell squats have tired your stabilizers.
References: KG Abelbeck, "Biomechanical Model and Assessment of an Exercise with Linear Motion in Squat", Journal of Strength and Conditioning Research, 16 (4): 516-24, 2002; M.L. Cotterman et al., "Comparison of muscle power production using the Smith machine and free weights for bench presses and squat exercises", Journal of Strength and Conditioning Research, 19 (1): 169-76, 2005.