Relationships between barbell squat strength and weightlifting performance

Abstract

Weightlifters compete in the snatch, clean and jerk, and total (snatch + clean and jerk). Commonly used assistance exercises for training weightlifters are front barbell squats and back barbell squats. The purpose of this study was to determine relationships between the front barbell squats and back barbell squats one repetition maximum (1 RM) and the snatch, clean and jerk, and total 1 RM. Senior male competitive weightlifters (n = 72) served as subjects in the survey. Significant correlations were found between front barbell squats and snatch, clean and jerk, or total 1 RM (r²= 0.85, 0.88, and 0.87 respectively) and between back barbell squats and snatch, clean and jerk, or total 1 RM (r²= 0.83, 0.84, and 0.83 respectively). Regression analyses indicate that 1 RM in the snatch, clean and jerk, and total are linearly related to the 1 RM in the front barbell squats and back barbell squats. Superior lifters appeared to be more efficient in using their back barbell squats strength during weightlifting compared to lower level lifters.

Keywords

Assistance exercises clean and jerk power snatch

Introduction

In the sport of weightlifting, two of the most commonly used assistance exercises are the back squat and the front squat.^1–6 There has been discussion within the weightlifting community and among sport science researchers about the relative contribution of these two assistance exercises to the amount of weight lifted in the snatch, the clean and jerk, and the total; where the total is the sum of the two competitive lifts.^6–13 Expanding the understanding of how front and back squat performance relates to the competitive lifts of a weightlifter could provide a guide for monitoring adaptation to progressive resistance training programs aimed at increasing performance.^{2,5–7,9,14–16} Stone et al.⁷ have previously reported very strong relationships between maximum strength as measured by one repetition maximum (1 RM) back squats and competitive weightlifting performances. Strong correlations were reported for both men and women weightlifters, even when results were scaled for body weight and height. That successful weightlifting performance is highly dependent on maximal strength is well established.^3,8,15 It has previously been suggested that the relationships between squat strength and competitive weightlifting differs depending on weight class and on lifting classification level; however, no statistical analysis was performed on these data.^12,13 Thus, it is not clear if highly successful weightlifters are more efficiently able to utilize their squat strength for the weightlifting movements when compared to their less successful counterparts.

It has been reported that elite weightlifters can back squat approximately ( $\bar{\times}$ ± SD) 127 ± 5.2% of their best clean and jerk.¹⁰ Other reports have provided similar values.^7,11–13,17 It has also been reported that clean and jerk world record holders had slightly superior squat results than nonworld record holders.¹⁰ One way to judge the relative training contributions of the front and back squats to the snatch, clean and jerk, and total involves calculating what Zatsiorsky called the “transfer of training results”.⁶ This index requires longitudinal sampling and comparisons of changes for the weightlifters’ 1 RM in the squat lifts and competitive lifts over time. Studies aimed at collecting the data necessary to calculate the statistical correlation between exercises, on the other hand, require only one performance measure per subject per exercise. With sufficient sample size, statistical correlations and regressions could be used to help identify relationships between front and back barbell squats and the snatch, clean and jerk, and total.

Shetty² found high correlations between body weight, back strength, leg strength, snatch, and clean and jerk. The high correlations between these variables were evident despite the fact that the snatch and the clean and jerk were measured with free weights, and leg and back strength were measured with a hip-back dynamometer. The fact that significant correlations between leg strength, back strength, and the weightlifting movements as previously reported suggests there may be significant correlations between front and back barbell squat performance and the snatch, clean and jerk, and weightlifting total.

Stone et al.¹⁵ reported high correlations (r = 0.77–0.94) between 1 RM squat performance and squat jump power executed with weights between 10% and 90% of squat 1 RM. The five strongest squatters produced peak power at 40% of squat 1 RM while the five weakest squatters produced peak power at 10% of squat 1 RM. These results suggest that increasing maximum squat strength may be an important means of increasing power performance in weightlifting, and that weightlifters with superior squat performances might produce more power while lifting a greater percentage of their squat 1 RMs than weightlifters with inferior squat performances. This relates to the explosive strength deficit (ESD), as described by Zatsiorsky and Kraemer.⁶ ESD refers to the ability to efficiently utilize strength in time limited (or sport specific) situations. Weightlifting is time limited, and Stone et al.’s¹⁵ findings that squat strength and explosive performance are correlated suggests that greater force production may supplement explosive performance. Similar findings were reported by Carlock et al.,¹⁷ who found high correlations between 1 RM squat and counter-movement jump (r = 0.91), snatch 1 RM (r = 0.93), and clean and jerk 1 RM (r = 0.95), suggesting that squatting ability is highly correlated with explosive performance. What is not known is whether the most successful weightlifters are able to more effectively use their strength during the weightlifting movements.

The purposes of this study were to determine the relationships between squatting ability (back and front) and the competition lifts (clean and jerk, snatch, and total) in trained, male weightlifters between the ages of 18 and 35. The first hypothesis (H₁) tested was that significant correlations and linear relationships exist between squatting ability and weightlifting performance. The second hypothesis (H₂) tested was that superior and inferior lifters do not differ in their ability to express squat strength through the weightlifting events.

Methods

Subjects

Seventy-two male subjects (ages 18–35 years, body mass = 89.2 ± 22.1 kg [̅ ± SD]), who were currently competing in the sport of weightlifting and were registered athletes with USA-Weightlifting, were recruited for the survey. They were interviewed by telephone, e-mail, or in-person. The subjects reported their bodyweight as well as their 1 RM in the back squat, front squat, snatch, clean and jerk, and weightlifting total. To be eligible for inclusion in this study, all subjects had been consistently training for at least the previous six months specifically to compete in weightlifting competitions. Additionally, 1 RMs for all training lifts (back and front squats) had to be performed within one weight class of the actual weightlifting performances (snatch, clean and jerk and total). All subjects were able to report current 1 RM performances for both front and back squats, except one who did not perform front squats. This study was approved by the University Institutional Review Board, and participation in the survey constituted informed consent. Descriptive training and competition data for the 72 subjects are listed in Table 1.

Table 1.

Subject performances (kg) for the test variables.

	N	Minimum	Maximum	̅ ± SD	% of back squat	% of front squat
Back squat	72	100	365	215.8 ± 47.7	–	–
Front squat	71	90	280	182.7 ± 39.9	85	–
Clean + Jerk	72	70	232.5	156.3 ± 33.5	72	86
Snatch	72	60	192.5	125.7 ± 27.7	58	69
Total	72	130	425	279.7 ± 60.5	–	–

Subject performances were determined from USA-Weightlifting’s year-end ranking list by weight class for total achieved in competition. The average rank of the top five weightlifters that participated as subjects in this study was approximately 1st in the nation for their weight class, while the average rank of the bottom five weightlifters was approximately 143rd in the nation for their weight class. Using Kauhanen’s Golden Standard bodyweight correction for total,¹⁸ the mean weightlifting total for the sample was ̅ ± SD = 76.5 ± 13.2% of the current normal world-class performance. This mean served at the dividing point for splitting the sample into top (high-level) and bottom (low-level) categories. These categories allowed for the comparison of high-level and low-level lifters, and how efficiently squat-strength was used.

Design

Data were collected via phone, email, and personal interviews. Results were used to determine if a significant correlation exists between the 1 RM of the snatch, clean and jerk, total, front squat, and back squat for competitive male weightlifters 18–35 years of age. When exercise performance measures were significantly correlated, simple linear regression was used to determine the theoretical relationship between the 1 RM’s of these exercises. The large range in lifting abilities permitted comparison of the total/squat 1 RM ratio of both high-level and low-level weightlifters, which might reflect the ability of high-level weightlifters to more effectively use squat strength during weightlifting competition. To avoid bias introduced by using weightlifters trained at the same club or by the same coaching system, lifters were selected from a variety of weightlifting clubs and training backgrounds. Weightlifters were sought who were of any level of ability—novice to elite. There was no minimum performance requirement.

Statistical analysis

To test the first hypothesis, 1 RMs for back squat, front squat, snatch, clean and jerk, and total were analyzed by Pearson product-moment correlation coefficients for the entire subject population. Simple linear regressions were then calculated to predict snatch 1 RM, clean and jerk 1 RM, and total weightlifting performance from back squat 1 RM and front squat 1 RM, respectively. To test the second hypothesis, the top half of the sample was compared to the bottom half of the sample using a measure of efficiency. This measure of efficiency was calculated by ranking the subjects based on their bodyweight corrected weightlifting total using Kauhanen’s formula.¹⁸ This allowed the comparison of weightlifting totals to be based on weightlifting ability, not body mass. The subject pool was then divided at the mid-point to delineate the top (high-level weightlifters) and the bottom half (low-level weightlifters) of the sample. A two tailed t-test was used to determine if the top and bottom half of the sample differed significantly in weightlifting ability. All reported values are ̅ ± SD.

Results

On average, the weightlifters were able to clean and jerk 72% and 86% of their back and front squats, respectively. Additionally, they were able to snatch 58% and 69% of their back and front squats, respectively. Furthermore, front squat 1 RM was 85% of back squat 1 RM (see Table 1). All of the test variables (snatch, clean and jerk, total, front squat, back squat, and bodyweight) were significantly correlated with each other (r ≥ 0.91; p ≤ 0.01; see Table 2). Absolute back squat performance explained approximately 83%, 84%, and 83% of the variance (r²) in snatch, clean and jerk, and total performance, respectively. Absolute front squat performance explained approximately 85%, 88%, and 87% of the variance (r²) in snatch, clean and jerk, and total performance, respectively (see Figure 1). Additionally, the ratios between front and back squat strength compared to weightlifting performances reported in the present study were somewhat similar to previous reports in the literature (see Table 3).^7,10–13,17

Figure 1.

Scatter plots of back squat (n = 72) or front squat (n = 71) and snatch, clean and jerk, or total (snatch + clean and jerk) results in kilograms with simple linear regressions.

Table 2.

Correlation coefficients (r) for the test variables.

	Front squat	Clean and Jerk	Snatch	Total
Back squat	0.96*	0.91*	0.91*	0.91*
Front squat		0.94*	0.92*	0.93*
Clean and jerk			0.98*	0.99*
Snatch				0.99*

p < 0.01.

Table 3.

Ratios between weightlifting performances and front or back squat strength in the present study and as previously reported in the literature.

	C&J/FS	C&J/BS	Sn/FS	Sn/BS	Total/FS	Total/BS	FS/BS
Present study	0.86	0.72	0.69	0.58	1.53	1.30	0.85
Carlock et al.¹⁷	–	0.74	–	0.59	–	1.34	–
Stone et al.⁷	–	0.74	–	0.60	–	1.34	–
Charniga¹⁰	–	0.79	–	–	–	–	–
Baker¹¹	–	0.77–0.81	–	0.60–0.64	–	–	–
Roman¹²	–	0.73–0.80^a	–	–	–	–
Laputin and Oleshko¹³	–	0.71–0.79^a	–	–	–	–

C&J: clean & jerk; Sn: snatch; Total: C&J + Sn; FS: front squat; BS: back squat.

Values depend on weight class and lifting classification, derived from data reported.

The top and bottom half of the sample differed significantly in weightlifting ability. The top half performed at a mean of 87.1 ± 6.6% of the world-class performance, while the bottom half performed at a mean of 66.6 ± 9.6% of world-class performance. The mean of the bottom half differed significantly from the mean of the top half (p < 0.01). The top and bottom half of the sample also differed significantly in their efficiency ratios for weightlifting total divided by back squat, but did not differ significantly in their efficiency ratios for weightlifting total divided by front squat. Table 4 shows the efficiency ratios for the top and bottom half of the sample. Figure 2 displays the scatter plot of the top and bottom halves’ weightlifting efficiency in relation to their back squat abilities. The vertical line indicates the point where the top and the bottom half of the sample were separated, while the dotted lines indicate the mean ratio for each half.

Figure 2.

Comparison of top and bottom half of sample’s efficiency ratios for weightlifting total 1 RM divided by back squat 1 RM.

Table 4.

Efficiency ratios (quotient of both total/front squat and total/back squat) for the top (high-level) and bottom (low-level) half of the sample.

	Minimum	Maximum	Mean	Standard deviation	N
Total divided by front squat
Top half	1.32	1.83	1.56	0.12	35
Bottom half	1.28	1.82	1.51	0.14	35
Total divided by back squat
Top half	1.11	1.49	1.33	0.09	36
Bottom half	1.00	1.55	1.27^a	0.13	36

Different from top half (p < 0.01)

Discussion

The results of this study support H₁ and partially support H₂. The r² values for the correlations of determination for absolute front and back squat to the snatch, clean and jerk, and weightlifting total were equal to or greater than 83% (p < 0.01) supporting the hypothesis that barbell squats and weightlifting performance are highly correlated. This was anticipated by Shetty² who reported relatively high correlations between snatch, clean and jerk, back strength, leg strength, and bodyweight. The current study and Shetty’s study support the contention that general strength measures of the hip and knee extensors, such as during the barbell squat, are highly correlated with weightlifting performance. The results of the regression analyses indicate a high degree of linearity between barbell squats and weightlifting performance.

The high-level lifters in the top half of the sample displayed a statistically greater (p < 0.01) level of efficiency in their weightlifting performance relative to their back squat performance (WL total/back squat 1 RM = 133 ± 9%) than the low-level lifters in the bottom half of the sample (WL total/back squat 1 RM = 127 ± 13%). This study also found that weightlifters, in general, total 153 ± 13% of their front squat 1 RM, but there was no difference between the top and bottom halves of the sample. This result supports suggestions by Stone et al.¹⁶ that the back squat’s primary contribution to weightlifting may be to provide the overload or conditioning impetus necessary to increase the percentage of back squat 1 RM at which highest power outputs occur.

Although it is beyond the scope of this study, the results of the efficiency analysis may be indicative of a higher degree of specificity between front squat and weightlifting performance than between back squat and weightlifting performance. This could be the result of the similarity between the technical requirements of the front squat and the clean and jerk, which are both highly correlated with total weightlifting performance. However, the higher degree of specificity between front squat performance and weightlifting performance could also be a function of the high degree of similarity between the loads used during front barbell squats, the snatch, and the clean and jerk. If the similarity of the loads used during front barbell squats and the weightlifting events explains the seemingly higher degree of specificity between these exercises, then the difference between superior and inferior weightlifters in their ability to express back squat strength through weightlifting performance may be indicative of differences in their ESD. As such, the ratio between back squat performance and weightlifting performance may represent a modified measure of ESD that is readily accessible through field-testing (i.e. back squats for maximal strength and weightlifting performances for high power or explosiveness). Future studies are necessary to examine the efficacy of this modified ESD measure for monitoring training progress and performance.

This study presents several important points about the relationship between barbell squat and weightlifting performances. First, this and other studies have shown that the absolute force capabilities of the primary muscles used in weightlifting are highly correlated to the amount of weight lifted in the snatch, clean and jerk, and total for trained, male weightlifters.^2,18–20 This study also indicates that the efficiency with which a weightlifter demonstrates back squat strength through the snatch, clean and jerk, and total is reflective of the competitive level of the weightlifter, with superior weightlifters attaining a higher degree of efficiency (and possibly lower ESD) than inferior weightlifters. In addition, the efficiency with which a weightlifter demonstrates front squat strength through the snatch, clean and jerk, and total was not found to differ significantly between superior and inferior weightlifters. In other words, differences in weightlifting results are related to the front squat without regard to training or competitive level. In addition, a cursory examination of Table 4 illustrates that the back squat ratios in comparison to weightlifting performance as seen in the present study are at the low end of values reported by others.^7,10–13,17 Although this slight difference may be inconsequential, it is also possible that the previous reports examined only highly accomplished weightlifters, whereas the present study included athletes with a larger range of weightlifting ability. These small differences in the back squat to weightlifting ratios may be indicative of greater lifting efficiency with more accomplished lifters, as suggested in the present study.

In conclusion, the results of the present study indicate that both the front and back barbell squats are highly correlated with weightlifting performances. This is apparent across a wide range of weightlifting abilities. Additionally, these relationships are linear in nature, indicating the critical role of maximal lower body strength for successful weightlifting performance. It is also evident that the most successful competitive weightlifters are slightly more efficient using their maximal strength as shown by their significantly greater weightlifting total/back squat ratios.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

References

Takano

. Coaching optimal technique in the snatch and the clean and jerk. Natl Strength Condit Assoc J 1987; 9: 50–59.

Shetty

. Quantification of selected segmental strengths in weightlifting. J Appl Sports Sci Res 1990; 4: 37–41.

Garhammer

. A review of power output studies of Olympic and Powerlifting: methodology, performance prediction, and evaluation tests. J Strength Cond Res 1993; 7: 76–89.

Harris

Stone

O’Bryant

, et al. Short-term performance effects of high speed, high force, or combined weight training methods. J Strength Cond Res 2000; 14: 14–20.

Kraemer

Adams

Cafarelli

, et al. American College of Sports Medicine position stand on progression models in resistance training for healthy adults. Med Sci Sports Exerc 2002; 34: 364–380.

Zatsiorsky

Kraemer

. Science and practice of strength training, 2nd ed. Champaign, IL: Human Kinetics, 1982.

Stone

Sands

Pierce

, et al. Relationship of maximum strength to weightlifting performance. Med Sci Sports Exerc 2005; 37: 1037–1043.

Aján

Baroga

. Weightlifting: fitness for all sports, Budapest: Medicina Publishing House, 1988.

Piper

Erdmann

. A combined weightlifting/powerlifting program. Strength Cond 1998; 20: 15–19.

10.

Charniga A. The relative value of the back squat in the training of weightlifters, http://www.sportivnypress.com/2018/the-relative-value-of-the-back-squat-in-the-training-of-weightlifters/ (2001, accessed 9 January 2019).

11.

Baker

. Weightlifting coaching manual volume III - Training program design, Colorado Springs, CO: USA-Weightlifting, 1987.

12.

Roman RA. The training of the weightlifter. Moscow: Fizcultura I Spovt, 1986 (Translated by A. Charniga, Livonia, MI: Sportivny Press, 1988).

13.

Laputin NP and Oleshko VG. Managing the training of weightlifters. Kiev: Zdorov’ya Publishers, 1982 (Translated by A. Charniga, Livonia, MI: Sportivny Press, 1988).

14.

Charniga A. Concerning the “Russian squat routine”, http://www.sportivnypress.com/2018/concerning-the-russian-squat-routine/ (2001, accessed 9 January 2019).

15.

Garhammer

. Performance evaluation of Olympic weightlifters. Med Sci Sports 1979; 11: 284–287.

16.

Stone

O’Bryant

McCoy

, et al. Power and maximum strength performance of dynamic and static weighted jumps. J Strength Cond Res 2003; 17: 140–147.

17.

Carlock

Smith

Hartman

, et al. The relationship between vertical jump power estimates and weightlifting ability: a field-test approach. J Strength Cond Res 2004; 18: 534–539.

18.

Kauhanen

Komi

Häkkinen

. Standardization and validation of the body weight adjustment regression equations in Olympic weightlifting. J Strength Cond Res 2002; 16: 58–74.

19.

Hester

Hunter

Shuleva

, et al. Review and evaluation of relative strength handicapping models. Natl Strength Condit Assoc J 1990; 12: 54–57.

20.

Hunter

Hester

Snatchyder

, et al. Rationale and methods for evaluating relative strength handicapping models. Natl Strength Condit Assoc J 1990; 12: 54–57.