One has to admit that the classic back squats are tough to beat as an overall muscle and strength builder. It targets the quads, glutes, hamstrings, and lower back but also requires work from the core, upper back, and shoulders to stabilize the bar.
Because back squat is designed to let you lift heavy loads, it encourages bone growth and the release of muscle-supporting hormones such as testosterone and growth hormone. The problem is, most people simply can’t perform it correctly.
A well-performed back squat is rare. Everybody talks about it, but nobody sees it. Most deadlifts don’t have the hip mobility to squat without their tail-bone tucking under, which puts the lower back at risk for injury. They’ll also fall forward on the descent, or fail to push their hips back far enough, so their knees travel well in front of their toes, which may cause knee injury.
Despite these problems, most trainers still push back squats on their clients. A good trainer never pushes clients to perform back squats but instead opts to form the bulk of their lower- body training with front squats, trap-bar deadlifts, Romanian deadlifts, and different single-leg exercises.
Single-leg squatting: similar benefits but lower risk for injury
Working one leg at a time, as with the split squat, the lunge, or step-up workouts, is usually considered an adjunct to barbell-squat training, never the core of the leg exercise itself. It’s time to change that.
Single-leg workout routines offer similar benefits to classic squatting, but reduce the risk for injury. They let you get a training effect for your legs with much less load.
If you can back squat 225 pounds for five, but do Bulgarian split squats (take a staggered stance and lift your back foot on a bench) with 75-pound dumbbells, which is 150 pounds total, your legs will get a lot more load without subjecting your spine to 225 pounds.
You can put more than one hundred pounds directly on one leg (studies show the back leg takes up about 15% of the load)—which is more than the back squat can load on each leg, given how the weight is distributed (your back and shoulders take on a lot of the weight).
In other words, split squatting provides a more direct leg hit. It’s also easier to keep your shins vertical (so the knee doesn’t move past the toe) when performing a squat on one leg, and so you can avoid placing shear forces on the patella.
Knee pain is usually caused by weak glutes and single-leg workout routines force you to stabilize in three planes of movement, which works the glutes hard.
Finally, since single-leg exercising must be done lighter, it doesn’t cause the same nervous-system fatigue that heavy squats or deadlifts do, so it can be done three or four times a week without fear of overtraining.
For example, you could do Bulgarian split squats on Monday, lunges on Wednesday, and step-ups Friday. More frequent training means more stimulus for growth.
Interestingly, the same doesn’t go for training one arm at a time. There’s no less load on your joints when doing single-arm presses instead of double-arm.