You may have heard that the squat, bench, and deadlift are must-do exercises. And, for powerlifters, they may well be. Specificity is paramount, after all. However, what about for recreational lifters, whose goals don’t center around the powerlifts? Can we replace the powerlifts with alternative variations and see similar improvements in muscle size?
Study overview
A recent study by Enes and colleagues compared the effects of either back-squatting or front-squatting on lateral quad thickness (30, 50, 70% of muscle length) and 45° leg press 1RM. The researchers had 24 recreationally trained females train either the front squat or back squat for 12 weeks.
Participants trained twice a week. For the squat, to increase the odds of seeing a robust amount of muscle growth, participants took their previous quad training volume and increased their weekly set counts by 20%. Additionally, participants increased volume a further 20% every four weeks on the squat during the 12 week training intervention.
If you’re wondering why the researchers opted to do this, a few previous studies have found that individualizing volume results in better muscle growth than simply blanket-assigning the same amount of volume to every individual (1, 2). While the jury is still out, it was a precautionary measure taken to increase the magnitude of muscle growth seen.
Results
Though both groups gained strength, leg press 1RM increased significantly more in the back squat group compared to the front squat group. Increases in thickness of the lateral thigh (vastus lateralis and intermedius) were similar among the groups.
These findings are odd. On the one hand, increases in muscle size were similar between the two squat variations. On the other hand, strength gains did differ. Why?
In terms of muscle size, the front squat and back squat may be similarly effective. While there are biomechanical differences between the two movements, they may be similar enough that they result in similar hypertrophy of the quadriceps. Based on hip flexion versus knee flexion range of motion, it remains possible that the front squat emphasizes the quadriceps a bit more, whereas the back squat emphasizes the glutes/adductors a bit more.
In terms of strength, the authors surmise that the back squat could have led to greater strength gains for one of two reasons. The first explanation is that the back squat allows for greater loads to be used, improving neural adaptations. The second explanation is that the back squat strengthens the hip extensor musculature better than the front squat, since it allows for greater hip flexion.
Takeaways
Ultimately, for muscle growth, I still think the front squat and back squat are largely interchangeable. The front squat may emphasize the quadriceps and back extensor musculature a bit more, whereas the back squat may emphasize the glutes and adductors a bit more.
For strength, consider the principle of specificity carefully. Specificity appears to apply to joint angles/range of motion, repetition range, movement pattern, and more. So, for best strength gains, stay specific. If you’re a powerlifter, most of your training should be back squats to parallel depth, with fewer front squats. Likewise, if you’re an olympic weightlifter, front squats will probably be a bit more important to improve your clean.
