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Full squat produces greater neuromuscular and functional adaptations and lower pain than partial squats after prolonged resistance training

DOI:10.1080/17461391.2019.1612952
Authors:
Jesús G. Pallarés at University of Murcia
Jesús G. Pallarés
Alejandro Martínez Cava at University of Murcia
Alejandro Martínez Cava
Javier Courel Ibáñez at University of Granada
Javier Courel Ibáñez
Juan José González-Badillo at Universidad Pablo de Olavide
Juan José González-Badillo
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Abstract

The choice of the optimal squatting depth for resistance training (RT) has been a matter of debate for decades and is still controversial. In this study, fifty-three resistance-trained men were randomly assigned to one of four training groups: full squat (F-SQ), parallel squat (P-SQ), half squat (H-SQ), and Control (training cessation). Experimental groups completed a 10-week velocity-based RT programme using the same relative load (linear periodization from 60% to 80% 1RM), only differing in the depth of the squat trained. The individual range of motion and spinal curvatures for each squat variation were determined in the familiarization and subsequently replicated in every lift during the training and testing sessions. Neuromuscular adaptations were evaluated by one-repetition maximum strength (1RM) and mean propulsive velocity (MPV) at each squatting depth. Functional performance was assessed by countermovement jump, 20-m sprint and Wingate tests. Physical functional disability included pain and stiffness records. F-SQ was the only group that increased 1RM and MPV in the three squat variations (ES = 0.77–2.36), and achieved the highest functional performance (ES = 0.35–0.85). P-SQ group obtained the second best results (ES = 0.15–0.56). H-SQ produced no increments in neuromuscular and functional performance (ES = −0.11–0.28) and was the only group reporting significant increases in pain, stiffness and physical functional disability (ES = 1.21–0.87). Controls declined on all tests (ES = 0.02–1.32). We recommend using F-SQ or P-SQ exercises to improve strength and functional performance in well-trained athletes. In turn, the use of H-SQ is inadvisable due to the limited performance improvements and the increments in pain and discomfort after continued training.
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ORIGINAL ARTICLE
Full squat produces greater neuromuscular and functional adaptations
and lower pain than partial squats after prolonged resistance training
JESÚS G. PALLARÉS
1
, ALEJANDRO M. CAVA
1
, JAVIER COUREL-IBÁÑEZ
1
,
JUAN JOSÉ GONZÁLEZ-BADILLO
2
, & RICARDO MORÁN-NAVARRO
1
1
Faculty of Sport Sciences, Human Performance and Sports Science Laboratory, University of Murcia, Murcia, Spain &
2
Faculty of Sport, Pablo de Olavide University, Seville, Spain
Abstract
The choice of the optimal squatting depth for resistance training (RT) has been a matter of debate for decades and is still
controversial. In this study, fifty-three resistance-trained men were randomly assigned to one of four training groups: full
squat (F-SQ), parallel squat (P-SQ), half squat (H-SQ), and Control (training cessation). Experimental groups completed
a 10-week velocity-based RT programme using the same relative load (linear periodization from 60% to 80% 1RM), only
differing in the depth of the squat trained. The individual range of motion and spinal curvatures for each squat variation
were determined in the familiarization and subsequently replicated in every lift during the training and testing sessions.
Neuromuscular adaptations were evaluated by one-repetition maximum strength (1RM) and mean propulsive velocity
(MPV) at each squatting depth. Functional performance was assessed by countermovement jump, 20-m sprint and
Wingate tests. Physical functional disability included pain and stiffness records. F-SQ was the only group that increased
1RM and MPV in the three squat variations (ES = 0.77–2.36), and achieved the highest functional performance (ES =
0.35–0.85). P-SQ group obtained the second best results (ES = 0.15–0.56). H-SQ produced no increments in
neuromuscular and functional performance (ES = −0.11–0.28) and was the only group reporting significant increases in
pain, stiffness and physical functional disability (ES = 1.21–0.87). Controls declined on all tests (ES = 0.02–1.32). We
recommend using F-SQ or P-SQ exercises to improve strength and functional performance in well-trained athletes. In
turn, the use of H-SQ is inadvisable due to the limited performance improvements and the increments in pain and
discomfort after continued training.
Keywords: Muscle strength,velocity-based resistance training,propulsive phase,lumbar spine
Highlights
.Training at F-SQ produced the greatest improvements in all neuromuscular performance parameters for the three
squatting depths. In contrast, intervention with H-SQ produced the worst results.
.Whereas individuals improved more at the specific depth at which they trained, results from the F-SQ group were still the
best.
.The three groups reported a moderate rise in pain perception scores following the 10-week RT program, but the H-SQ
experienced an acute increase in pain, stiffness and physical functional disability indexes.
.According to these findings, we conclude that F-SQ and P-SQ are the safest and most effective squat exercises to improve
strength and functional performance, while H-SQ is unadvisable given the limited benefits and high discomfort.
Introduction
The back squat (SQ) is one of the most widely used
and effective resistance training (RT) exercises for
strengthening the lower-limb, protecting against inju-
ries and improving athletic performance (Hartmann,
Wirth, & Klusemann, 2013). In the last three
decades, numerous publications have found that
increases in lower-body strength following SQ train-
ing transfer positively to functional athletic perform-
ance in short-duration actions that demand
maximal voluntary contractions, such as sprinting
and vertical jumping (Hartmann et al., 2012; Seitz,
Reyes, Tran, de Villarreal, & Haff, 2014; Suchomel,
Nimphius, & Stone, 2016; Wirth et al., 2016).
© 2019 European College of Sport Science
∗Correspondence: Jesús García Pallarés, Faculty of Sport Sciences, Human Performance and Sports Science Laboratory, University of
Murcia, C/ Argentina s/n. Santiago de la Ribera, Murcia, Spain. E-mail: jgpallares@um.es
European Journal of Sport Science, 2019
https://doi.org/10.1080/17461391.2019.1612952
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Full-text available
  • Apr 2016
Strength training-induced increases in speed-strength seem indisputable. For trainers and athletes the most efficient exercise selection in the phase of preparation is of interest. Therefore, this study determined how the selection of training exercise influences the development of speed-strength and maximal strength during an 8-week training intervention. 78 students participated in this study (39 in the training group and 39 as controls). Both groups were divided into two subgroups. The first training group (squat training group [SQ]) completed an 8-week strength training protocol using the parallel squat. The 2nd training group (leg-press training group [LP]) used the same training protocol using the leg-press (45[degrees]-leg-press). The control group was divided in two subgroups as controls for the SQ or the LP. A two-factorial analyses of variance was performed using a repeated measures model for all group comparisons and comparisons between pre- and post-test results. The SQ exhibited a statistically significant (p<0.05) increase in jump performance in Squat jump (SJ, 12.4%) and Countermovement jump (CMJ, 12.0%). Whereas, the changes in the LP did not reach statistical significance and amounted to improvements in SJ of 3.5% and CMJ 0.5%. The differences between groups were statistically significant (p<0.05). There are also indications that the squat exercise is more effective to increase Drop Jump performance. Therefore, the squat exercise increased the performance in SJ, CMJ and RSI more effectively compared to the leg-press in a short-term intervention. Consequently, if the strength training aims at improving jump performance the squat should be preferred because of the better transfer effects.
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Increases in Lower-Body Strength Transfer Positively to Sprint Performance: A Systematic Review with Meta-Analysis
Article
Full-text available
  • Jul 2014
Background: Although lower-body strength is correlated with sprint performance, whether increases in lower-body strength transfer positively to sprint performance remain unclear. Objectives: This meta-analysis determined whether increases in lower-body strength (measured with the free-weight back squat exercise) transfer positively to sprint performance, and identified the effects of various subject characteristics and resistance-training variables on the magnitude of sprint improvement. Methods: A computerized search was conducted in ADONIS, ERIC, SPORTDiscus, EBSCOhost, Google Scholar, MEDLINE and PubMed databases, and references of original studies and reviews were searched for further relevant studies. The analysis comprised 510 subjects and 85 effect sizes (ESs), nested with 26 experimental and 11 control groups and 15 studies. Results: There is a transfer between increases in lower-body strength and sprint performance as indicated by a very large significant correlation (r = -0.77; p = 0.0001) between squat strength ES and sprint ES. Additionally, the magnitude of sprint improvement is affected by the level of practice (p = 0.03) and body mass (r = 0.35; p = 0.011) of the subject, the frequency of resistance-training sessions per week (r = 0.50; p = 0.001) and the rest interval between sets of resistance-training exercises (r = -0.47; p ≤ 0.001). Conversely, the magnitude of sprint improvement is not affected by the athlete's age (p = 0.86) and height (p = 0.08), the resistance-training methods used through the training intervention, (p = 0.06), average load intensity [% of 1 repetition maximum (RM)] used during the resistance-training sessions (p = 0.34), training program duration (p = 0.16), number of exercises per session (p = 0.16), number of sets per exercise (p = 0.06) and number of repetitions per set (p = 0.48). Conclusions: Increases in lower-body strength transfer positively to sprint performance. The magnitude of sprint improvement is affected by numerous subject characteristics and resistance-training variables, but the large difference in number of ESs available should be taken into consideration. Overall, the reported improvement in sprint performance (sprint ES = -0.87, mean sprint improvement = 3.11 %) resulting from resistance training is of practical relevance for coaches and athletes in sport activities requiring high levels of speed.
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Velocity- and power-load relationships in the half, parallel and full back squat
Article
  • Nov 2018
This study aimed to compare the load-velocity and load-power relationships of three common variations of the squat exercise. 52 strength-trained males performed a progressive loading test up to the one-repetition maximum (1RM) in the full (F-SQ), parallel (P-SQ) and half (H-SQ) squat, conducted in random order on separate days. Bar velocity and vertical force were measured by means of a linear velocity transducer time-synchronized with a force platform. The relative load that maximized power output (Pmax) was analyzed using three outcome measures: mean concentric (MP), mean propulsive (MPP) and peak power (PP), while also including or excluding body mass in force calculations. 1RM was significantly different between exercises. Load-velocity and load-power relationships were significantly different between the F-SQ, P-SQ and H-SQ variations. Close relationships (R² = 0.92–0.96) between load (%1RM) and bar velocity were found and they were specific for each squat variation, with faster velocities the greater the squat depth. Unlike the F-SQ and P-SQ, no sticking region was observed for the H-SQ when lifting high loads. The Pmax corresponded to a broad load range and was greatly influenced by how force output is calculated (including or excluding body mass) as well as the exact outcome variable used (MP, MPP, PP).
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Effects of velocity loss during resistance training on athletic performance, strength gains and muscle adaptations
Article
  • Mar 2016
We compared the effects of two resistance training (RT) programs only differing in the repetition velocity loss allowed in each set: 20% (VL20) vs 40% (VL40) on muscle structural and functional adaptations. Twenty-two young males were randomly assigned to a VL20 (n = 12) or VL40 (n = 10) group. Subjects followed an 8-week velocity-based RT program using the squat exercise while monitoring repetition velocity. Pre- and post-training assessments included: magnetic resonance imaging, vastus lateralis biopsies for muscle cross-sectional area (CSA) and fiber type analyses, one-repetition maximum strength and full load-velocity squat profile, countermovement jump (CMJ), and 20-m sprint running. VL20 resulted in similar squat strength gains than VL40 and greater improvements in CMJ (9.5% vs 3.5%, P < 0.05), despite VL20 performing 40% fewer repetitions. Although both groups increased mean fiber CSA and whole quadriceps muscle volume, VL40 training elicited a greater hypertrophy of vastus lateralis and intermedius than VL20. Training resulted in a reduction of myosin heavy chain IIX percentage in VL40, whereas it was preserved in VL20. In conclusion, the progressive accumulation of muscle fatigue as indicated by a more pronounced repetition velocity loss appears as an important variable in the configuration of the resistance exercise stimulus as it influences functional and structural neuromuscular adaptations.
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