Among free-weight exercises, the barbell squat is second in popularity only to the barbell bench press. Power lifters, athletes, and fitness enthusiasts have performed barbell squats for decades. Indeed, many fitness professionals contest that the barbell squat is the single most result producing strength-training exercise for those looking to increase the strength, endurance, and power in the muscles of the hips, buttocks, and thighs. However, a closer examination indicates that the barbell squat has some important limitations. In fact, it is one of the exercises we choose to avoid at Discover Strength.
This movement involves the large muscles of the lower body and is valuable not only for improving strength, but also for providing a cardio-respiratory stimulus and a powerful improvement in resting metabolic rate (the number of calories we burn while we are at rest). One of the primary problems with the barbell squat is this: The barbell squat involves placing a barbell on your back, which vertically compresses the spinal column. In all circumstances, this is dangerous and contributes to the long-term degradation of the spine. Many proponents of the squat contest, “the squat is safe as long as you maintain good form.” However, it is impossible to avoid this dangerous spinal compression; and form has nothing to do with it. The barbell squat is inherently dangerous, even with perfect form.
A properly designed leg press machine eliminates this spinal compression.
This makes it virtually impossible to apply the intense strength-training stimulus that the glutes and quadriceps require. A properly designed leg press limits the involvement of the lower back and thus insures muscle fatigue of the glutes and quadriceps as the true cause of muscle failure (rather than the musculature of the lower back).
In summary, we prefer intelligently designed leg presses to barbell squats as a leg press insures safer and more intense training for the targeted musculature. And if a leg press isn’t available, a variety of squats or lunges that don’t involve vertically compressing the spine is always preferred.