The first thing to point out is that any given athlete is capable of lifting more weight in a back squat than in a front squat. That is a universal truth. Go ahead and test it. Typically people who are good at both squats will be able to front squat 75-80% of their max back squat. It is possible that with strictly front squat experience, someone could have a higher front squat. But even then, some practice of back squat will result in that movement being stronger. Of course lifting for athletes should often focus on speed rather than heavy weight. Along with being stronger, the back squat is also faster than a front squat at a given weight. This is the case for two reasons. First, for most athletes front squat strength is limited by the upper body. I just want to make clear that does not indicate a problem with the athlete. A front squat places the bar on the shoulder girdle (shoulder blades and clavicles) in a position where the supporting upper body muscles are at a severe mechanical disadvantage compared to the bar placement of a back squat. It is extremely challenging to support a lot of weight in front of the neck and simply not possible to transfer the same force into the bar as in a back squat. A front squat should be limited by upper body strength. If it is not, it is more likely a testament to a lack of leg strength than anything else. Second, even if supporting the weight with the arms is not an issue, the position of a front squat is not as strong as a back squat biomechanically. The front squat requires a more upright torso and more forward knee movement, and thus further knee flexion to get down to parallel when compared to the back squat. The result is a greater demand on the quadriceps muscles and knees and some of the stress being taken off the glute muscles and hips. Since the hips are easily the stronger and more powerful joint, taking load off them and putting it on the knees results in a weaker movement.
Given that the back squat is stronger and faster, centering training around the front squat instead would require some other very convincing reasons. The primary argument looks at the posture of the two movements. The
|Bad Back Squat|
|Bad Front Squat|
Another proposed reason to use front squats is to target the quads more. The first issue with this is whether or not targeting the quads is a good thing. Quad dominance (as opposed to glute dominance) is a common problem, particularly among inflexible athletes and inexperienced lifters. For a quad-dominant athlete, choosing a more quad-dominant squat is the wrong decision. But let's say quad development is the goal. A
|Olympic Back Squat|
There is one more argument to be addressed. There are claims that back squats cause tight hip flexors and a butt-out, belly-out posture (see picture). The theory is that back squats involve an over-arching of the lower back to deal with the torque on the spine when the torso is leaning forward. Along with the arch in the back comes anterior pelvic tilt and shortened hip flexors. This posture is really only used in powerlifting squats. It does not apply to squats on the olympic end of the spectrum. However, it is used in deadlift and clean and snatch from the hang position, so the argument should be addressed. First consider the lower back
|Anterior Pelvic Tilt|
It may seem like I have completely trashed front squats. I want to make clear that there is absolutely nothing bad about the exercise. For people who just want to be fit or just want to have good mobility and functionality or even athletes who do not need to be stronger, it is perfectly fine to use front squats instead of back squats. In fact, those people can take it a step further and just use overhead squats exclusively. They use an upright torso and a focus on the quads just like front squats. And they also demand even more in terms of hip mobility and correct posture. All the same arguments and then some can be made for using overhead squats instead of back squats. So why not do it? Because they don't allow you to lift a lot of weight. That's the key point. For athletes and lifters who need to be as strong as possible, lifting should be centered around the back squat. That does not mean front squats cannot be used, but they should be considered an assistance exercise to the back squat.
Another thing to address is the fact that there are a lot of elite lifters who use front squats. Most of them are olympic lifters. They have to front squat to finish the clean, so they have to be good at it. The fact that they can front squat extremely heavy weight does not mean that is what made them strong. They still use back squats because back squats develop a higher level of strength. It's very easy to see a video of an elite olympic lifter front squatting 250 kg and think that front squats are the key to getting strong. I believe this is where front squats get a lot of their credibility. It's important to realize that the same lifter who front squats 250 kg probably back squats over 300 kg. So which is going to make that lifter stronger? The answer is obvious. Are there lifters who have reached a high level of strength just using front squats? Yes. But consider the thousands of squats done to gain that strength. What if each rep was done with 20% more weight? How strong would the person be then? It's not that front squats can't make you strong. It's just that back squats will make you stronger. And that is why athletes should choose back squats.