Full vs. Half-Squats - Study Measures Actual Size Gains! A Tie for Quads, a Fail for Hams, and a Small Win for Glutes
|The result, the full-squat is slightly superior, is not as clear as you may have expected it to be. Furthermore, the study suggests that you won't get away without an additional hamstring exercise if you want tree-trunk legs and a fabulous behind.|
The subjects were matched to the two groups according to their average baseline physical characteristics and the one-repetition maximum (#1RM) of full and half squats between the two groups. The latter, i.e. the 1RMs were ~1.25x and ~1.5x the guys' body weight on the full and half-squat, respectively - an observation that tells you that all participants, who were in their early twenties, were not exactly powerlifters, but they were also no couch-potatoes. Still, theywere required not to have participated in any organized resistance training program involving regular exercise for at least 1 year before testing.
Why would one use untrained subjects?
The authors explain the decision to use 'untrained' subjects with the argument that "the obtained results would be affected by the effects of training experiences before the experiment".
Full-squat group (n = 8)
Half-squat group (n = 9)
Body mass (kg)
1RM of full squat (kg)
1RM of half squat (kg)
Figure 1: Muscles of the lower limbs | Lumen Learning
- knee extensor muscles: rectus femoris (RF), vastus lateralis (VL), vastus intermedius (VI), and vastus medialis (VM),
- hamstring muscles: biceps femoris short head (BFs), biceps femoris long head (BFl), semitendinosus (ST), and semimembranosus (SM), and
- adductor muscles: adductor magnus, adductor longus, and adductor brevis
|That's a half squat: Knee angle 90°|
#FST - The full squat was performed from complete knee extension to approximately 140° knee flexion and then immediately returned to the extended knee position.
#HST - The half-squat was performed at the half range of motion squat (from complete knee extension to approximately 90° knee flexion) and then immediately returned to the extended knee.
"In order to become accustomed to training and acquire a correct form, subjects performed 3 sets of 60% 1RM × 10 repetitions in the first week, 3 sets of 70% 1RM × 8 repetitions in the second week, and 3 sets of 80% 1RM × 8 repetitions in the third week. [...] If subjects were able to perform 3 sets of 8 repetitions per set, the training load was increased by 5 kg for the next training session."Another detail of the methodology section that's important is the way the scientists calculated the training volume as the arithmetic product of load × repetition × movement distance of the barbell - that's important, because it takes into account that, due to the greater range of motion (87.9 ± 2.1 cm in FST and 53.8 ± 1.8 cm in HST), the full-squat will require significantly higher workloads on a per rep basis. This assumption does yet require that both train with identical weights. In view of the fact that the half-squat allowed for greater weights, it is still not surprising that - within the intra-group standard-deviations, there was ...
- no significant difference in the total training volume between FST (186.4 ± 34.0 kg*rep*m) and HST (198.4 ± 19.9 kg*rep*m | p = 0.388, ES = 0.45)
|Figure 2: Relative changes in one repetition maximum in full (upper) and half (lower) squat exercises for full squat training (open) and half squat training (closed) groups. *Significantly different from before (**p < 0.01, ***p < 0.001). #Significantly different between the two groups (##p < 0.01) | Kubo 2019|
But who cares about 1RMs? Gainz is what ya want, right?
The question: What's best for your gains has likewise been addressed before. In many cases, such as the previously cited 2016 study, with slight advantages (in terms of hypertrophy, not strength) for the full squat, i.e. "ass to the grass". The study at hand confirms that, but it adds that the size of the difference (pun intended) depends on the muscle group we're looking at (see Table 2). So, ...
- the volumes of knee extensor muscles significantly increased by 4.9 ± 2.6% in FST (p < 0.001, ES = 0.34) and 4.6 ± 3.1% in HST (p = 0.003, ES = 0.43) - Note: This was not a significant effect-size difference (p = 0.812, ES = 0.11) favoring the full squat for a muscle group we often refer to as the "quads" as a whole or for the muscle volumes of VL, VI, and VM between the two groups (p = 0.497–0.892, ES = 0.02–0.34), individually;
Study leaves no doubt: For the biceps femoris, Romanian deadlifts rule.
- the volumes of the adductor muscles significantly increased by 6.2 ± 2.6% in FST (p < 0.001, ES = 0.55) and 2.7 ± 3.1% in HST (p = 0.030, ES = 0.33) - Note: This time, however, with measurable, statistically and (potentially) practically relevant advantages for the full squat: More specifically, the volume of the gluteus maximus muscle significantly increased by 6.7 ± 3.5% in FST (p < 0.001, ES = 0.35) and only 2.2 ± 2.6% in HST (p = 0.041, ES = 0.14); a difference that was also observed for the adductor and gluteus maximus muscle volumes which were significantly greater in FST than in HST (p = 0.026, ES = 1.23 for the adductor muscles, p = 0.008, ES = 1.50 for the gluteus maximus muscle).
So, there's some truth to the often-heard recommendation to squat deep to form a strong and muscular behind. What is more important to remember, IMHO, is the fact that scientists rightly point out that "[t]he main results of the present study were that 10 weeks of full and half squat training increased the volumes of the vasti muscles, but not rectus femoris or hamstring muscles". Essentially, this implies that you will have to train both separately - for example by doing stiff-legged deadlifts (learn more about the best exercises in this previous article).
|Table 2: Muscle volume of each constituent of knee extensor muscles before and after training mean (sd)|
- Kubo, Keitaro, Toshihiro Ikebukuro, and Hideaki Yata. "Effects of squat training with different depths on lower limb muscle volumes." European journal of applied physiology (2019): 1-10.
- McAllister, Matt J., et al. "Muscle activation during various hamstring exercises." The Journal of Strength & Conditioning Research 28.6 (2014): 1573-1580.
- Neto, Walter Krause, Thais Lima Vieira, and Eliane Florencio Gama. "Barbell Hip Thrust, Muscular Activation and Performance: A Systematic Review." Journal of sports science & medicine 18.2 (2019): 198.