We almost all know and do the squat, after all, it is the exercise for muscle growth and strength increase in the lower body. You mainly train your quadriceps (legs) and glutes (buttocks) with it. But what if you mainly want to train your buttocks? There are two ways to make the squat a real buttocks exercise, at least according to the results of scientific research.
FULL VERSUS PARALLEL SQUAT
A study compared full squats to half squats based on the growth of the involved muscle groups. To do this, a group of male strength athletes were split in two: one group trained for 10 weeks with a full squat (140 degrees of knee flexion and almost all the way to the floor), the other with a parallel squat (90 degrees of knee flexion and not lower than parallel), with the same training volume. The researchers measured muscle mass using MRI at the beginning and at the end of the training period.
The result? Both training programs resulted in significant muscle growth of the gluteus maximus – however, significantly more in the full squat than in the half squat: 7% versus 2% muscle growth. The researchers also measured the distance the barbell had to travel in both conditions: 88 centimeters in the full squat versus 54 centimeters in the half squat. There was clearly a greater ROM in the full squat.
PREVIOUS STUDIES
In 2002, an electromyographic study (EMG) appeared that showed that the full squat activates the gluteus maximus more than the parallel squat. This is research based on muscle activation and therefore not on actual muscle growth.
Another EMG study, from 2016, found no differences in muscle activation between the different squat forms. However, EMG studies do not always appear to be reliable indicators of muscle growth and/or strength gains. For example, a biomechanical study from 2020 showed that deep squats are excellent glute builders: they were more than twice as effective for glute muscle growth as the hip thrust, which many coaches consider to be the glute exercise. So this was not an EMG study, but an actual measurement of muscle growth, after a twelve-week training program.
The researchers attribute the results to the large ROM in which the buttocks are stimulated during deep squats, while the ROM of hip thrust is relatively small. The fact that hip thrusts have the highest peak activation of the buttocks according to several EMG studies, does not appear to be of decisive importance in practice.
Luckily, you don’t have to choose: full squats and hip thrusts are both excellent glute builders regardless.
FULL SQUAT NOT FOR EVERYONE
Not everyone can squat full or Ass To Grass (ATG) . Do you struggle to keep your back straight during the squat, especially as you go deeper (parallel or lower)? Chances are that your flexibility and (ergo) your mobility are the limiting factors. Here are three tips to increase your ROM.
Do you ‘only’ squat parallel? No problem, a parallel squat is a full-fledged squat if you look at the most important target muscle, the quadriceps. Parallel is not a full ROM, but you can use more weight. In the end, you train your quads just as hard. If you also want a round butt, do other exercises, such as the hip thrust, cable pull-though and leg press.
INTENSITY OF THE SQUAT
How heavy you squat may also affect which muscles you stimulate most, according to a new study. Researchers had a group of powerlifters squat at 70-90% of their 1RM in 5% increments while estimating their muscle strength at each intensity.
Heavier squats, not surprisingly, led to greater muscle strength, but the magnitude of the increase varied considerably by muscle. The glutes experienced the greatest increase in force production with heavier squats, approximately twice as much as the quadriceps.
These findings suggest that if you want to emphasize the quads, you can do high-rep squats with some reps in reserve (RIR, that is, a few reps away from muscle failure). To fully engage the glutes, you need to go heavy, so for example, sets of six reps to near muscle failure.
Note that coach Menno Henselmans emphasizes that we need a long-term study to determine whether squat intensity (absolute and relative) actually influences which muscles grow the most from squatting.
SHOULD YOU SQUEEZE YOUR GLUTES?
Another common question is whether you need to squeeze your glutes at the top of the squat. According to glute expert Bret Contreras, you don’t need to. He has his clients squeeze their glutes during the hip thrust and the 45 degree hyper, but not during the squat.
In theory, squeezing your glutes during squats could increase the risk of injury, although Contreras thinks this risk is greatly exaggerated. As long as you don’t overdo it with squeezing, it’s doable, but the question remains whether it adds value, especially if you’re also doing the hip thrust.
CONCLUSION
If you want to optimize the growth stimulus for your gluteal muscles when squatting, squat low (below parallel) and heavy (below 10 repetitions and close to muscle failure).
The full squat, Ass To Grass, is one of the best exercises for your buttocks, next to the hip thrust. However, full squatting requires a lot of your flexibility and mobility; not everyone trains ATG without problems.
There is no need to squeeze your glutes when squatting.