Full Squats vs Half Squats: Study Reveals Muscle Growth Differences

The findings from this research indicate that full squats hold only a marginal edge over their partial counterparts, contrary to what many might anticipate. Moreover, the investigation highlights the necessity of incorporating dedicated hamstring workouts if the goal is to develop robust, tree-trunk

The findings from this research indicate that full squats hold only a marginal edge over their partial counterparts, contrary to what many might anticipate. Moreover, the investigation highlights the necessity of incorporating dedicated hamstring workouts if the goal is to develop robust, tree-trunk thighs and a well-rounded posterior.

A recent publication in the European Journal of Applied Physiology delved into the impacts of squat variations on the muscle volumes of the lower body. This approach marks a significant advancement, as prior research predominantly focused on immediate electromyography responses rather than long-term structural changes. The experiment featured a practical training regimen spanning 10 weeks, during which twenty young adult males were randomly divided into two cohorts: one performing full squats (FST group, n=10) and the other executing half squats (HST group, n=10) at the outset of the study.

Participants were carefully paired across groups based on their initial physical attributes and one-repetition maximum (1RM) strengths for both full and half squats. Notably, the 1RM values equated to approximately 1.25 times body weight for full squats and 1.5 times for half squats, suggesting that while these early-twenties individuals were not elite powerlifters, they were far from sedentary. Importantly, none had engaged in structured resistance training programs with regular sessions for at least one year prior to the study commencement.

Rationale for Selecting Untrained Participants

The researchers justified employing untrained subjects by noting that prior training histories could skew the outcomes, potentially confounding the effects attributable solely to the experimental protocol.

Full-squat group (n=8)

Half-squat group (n=9)

Age (years)

20.7 (0.4)

20.9 (0.8)

Height (cm)

173.6 (4.1)

172.3 (5.8)

Body mass (kg)

63.2 (6.6)

64.1 (6.1)

1RM of full squat (kg)

78.8 (14.6)

82.8 (15.2)

1RM of half squat (kg)

95.0 (16.0)

96.7 (15.0)

Table 1: Baseline age, physical characteristics, and 1RM values for both groups (mean ± SD). 1RM denotes one-repetition maximum.

Consistent with standard protocols in training interventions, participants were directed to adhere to their usual dietary habits and refrain from any supplementation throughout the study duration. Muscle hypertrophy was meticulously evaluated not through dual-energy X-ray absorptiometry or mere girth measurements, but via precise cross-sectional magnetic resonance imaging scans of the lower limb musculature (utilizing FLEXART MRT-50GP from Toshiba Medical Systems, Tokyo, Japan). The specific muscles assessed included:

• 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).
• Adductor muscles: adductor magnus, adductor longus, and adductor brevis.

An identical number of axial slices were captured pre- and post-training for each participant: 39.5 ± 2.3 slices for knee extensors, 37.2 ± 2.4 for hamstrings, 29.4 ± 3.1 for adductors, and 28.5 ± 1.5 for the gluteus maximus. These MRI images were subsequently processed on computers using Osirix DICOM analysis software (Pixmeo, Geneva, Switzerland).

Defining Full and Half Squats in This Study

Although universal consensus on squat depth classifications remains elusive, the procedures in this study provide clear parameters. The full squat group (FST) executed movements from full knee extension to roughly 140 degrees of knee flexion, promptly returning to extension. Conversely, the half squat group (HST) limited the range to 90 degrees of flexion from extension before reversing.

Training occurred twice weekly over 10 weeks. Both groups maintained a stance width approximating shoulder breadth, with the barbell rested atop the trapezius muscles. Lifting belts were permitted, and every session was overseen by experienced personnel to enforce proper depth and technique. The progression protocol began with acclimation: week one featured 3 sets of 60% 1RM for 10 reps; week two advanced to 70% 1RM for 8 reps; and week three utilized 80% 1RM for 8 reps. Loads increased by 5 kg in subsequent sessions upon completing all prescribed reps.

Training volume was quantified as load multiplied by repetitions and barbell displacement distance, accounting for the extended range in full squats (87.9 ± 2.1 cm for FST versus 53.8 ± 1.8 cm for HST). Despite this, and heavier feasible loads in half squats, total volumes showed no meaningful disparity: 186.4 ± 34.0 kg·rep·m for FST and 198.4 ± 19.9 kg·rep·m for HST (p=0.388, ES=0.45).

Diverging from earlier works that hinted at partial squat superiority for strength and power, this study evaluated transferability by testing 1RM in both squat variants post-intervention.

Figure 2: Percentage changes in 1RM for full (top) and half (bottom) squats in full squat training (open bars) and half squat training (filled bars) groups. Asterisks denote significant pre-post differences (**p < 0.01, ***p < 0.001). Hash marks indicate inter-group differences (##p < 0.01).

These results reveal that half squat trainees advanced substantially in their signature lift, matching full squatters therein. Yet, on full squats, half squatters lagged markedly (~10% gain versus ~30% for full squatters over 10 weeks), underscoring training specificity.

Muscle Hypertrophy Outcomes: Where Differences Emerge

Beyond strength, hypertrophy insights build on prior evidence, like a 2016 analysis favoring full squats for growth over strength alone. This study refines that view by muscle-specific responses (detailed in Table 2):

• Knee extensors (quadriceps overall) grew comparably: 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), with no inter-group distinction (p=0.812, ES=0.11). Individual vasti (VL, VI, VM) showed similar parity (p=0.497–0.892, ES=0.02–0.34).
• Hamstrings exhibited negligible changes across all components (BFs, BFl, ST, SM) in both groups (p=0.129–0.911, ES=0.01–0.07), challenging assumptions of depth-driven superiority.
• Adductors expanded more robustly in FST (6.2 ± 2.6%, p < 0.001, ES=0.55) than HST (2.7 ± 3.1%, p=0.030, ES=0.33). Gluteus maximus followed suit: 6.7 ± 3.5% in FST (p < 0.001, ES=0.35) versus 2.2 ± 2.6% in HST (p=0.041, ES=0.14), with significant FST advantages (p=0.026, ES=1.23 for adductors; p=0.008, ES=1.50 for glutes).

Table 2: Pre- and post-training volumes for knee extensor muscle components (mean ± SD).

The hamstring stagnation surprises, given EMG-based expectations, while glute and adductor favoritism toward full range aligns with common coaching cues. Key takeaway: neither squat variant substantially hypertrophied rectus femoris or hamstrings, necessitating adjunct exercises like stiff-legged deadlifts for comprehensive leg development.

Even if full squats are inaccessible, alternatives exist for glute emphasis, such as the aforementioned deadlift variations.

Key Takeaways and Programming Implications

Full squats confer two primary benefits over half squats: superior full-range 1RM progression and enhanced adductor/glute hypertrophy. These edges, however, are modest compared to bro-science hype. Critically, hamstrings demand separate targeting via exercises like stiff-legged deadlifts, irrespective of squat depth.

This contrasts with EMG-centric prior works on deadlifts or hip thrusts, which inferred hypertrophy from activation without volumetric confirmation. Here, direct MRI evidence underscores the need for balanced programming to achieve proportional lower body gains.

In summary, while full squats offer targeted advantages for certain muscles and strength specificity, no single variation suffices for complete leg development. Integrate complementary movements for optimal results, ensuring progressive overload and form adherence across all exercises.