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Inside This Issue
- How Does Lower-Body and Upper-Body Strength Relate to Maximum Split Jerk Performance?
- The Relationship of Lower-Body, Multijoint, Isometric and Dynamic Neuromuscular Assessment Variables with Snatch, and Clean and Jerk Performance in Competitive Weightlifters: A Meta-Analysis
Study: How Does Lower-Body and Upper-Body Strength Relate to Maximum Split Jerk Performance?
How does an athlete’s strength affect the split jerk? Are there any differences in strength abilities for male and female weightlifters?
Introduction
It is clear from previous research that strength is critically important for success in weightlifting. In the book “Managing the Training of Weightlifters” the authors use ratios of strength exercises such as front and back squat to predict what the performance in the snatch and clean and jerk should be (1). If an athlete is lacking in either lift and not in ratio with their strength numbers the training plan can be adjusted to fix technical issues or strengthen key muscle groups.
Later research has shown that greater strength is related directly to weightlifting performance. A study by Stone and colleagues demonstrated that a strong relationship (r=0.94-0.95) exists between the back squat 1 repetition maximum (1RM) and snatch and clean performance (2). A later study also linked the front squat to snatch and clean performance again with very strong correlations (r=0.92-0.94) (3). Less research has been conducted on the jerk exercise but a recent study by Soriano et al. linked the overhead press with the split jerk exercise showing very strong correlations between overhead press 1RM and the split jerk 1RM (r=0.90) (4). In addition, the authors examined differences between men and women which discovered males have a stronger correlation of upper body strength with jerk performance compared to women. This could provide some additional considerations for programming for athletes when attempting to maximize jerk performance.
While most previous work has looked at snatch and clean performance in relation to dynamic lower body strength, the current study examines the back squat, overhead press, and split jerk performance. This will allow for a better understanding of the underlying performance characteristics of the split jerk in order to maximize its development
Purpose
To examine the relationship of maximal upper and lower body strength on split jerk performance. The authors posed a hypothesis that greater split jerk performance (kg lifted) was related to greater upper and lower body strength. A secondary purpose was to examine differences between men and women and generate prediction equations.
Methods
Subjects
In total, 33 subjects (20 men and 13 women) participated in this study. They were regional to national level lifters and their strength and demographic characteristics can be found in table 1.
Table 1. Subject Characteristics
Methods
Subjects completed three total sessions which consisted of 1RM’s in the overhead press, split jerk, and back squat. Full details can be found in Figure 1. All sessions were conducted within two weeks of the first session and a minimum of three days was provided between sessions. Authors conducted Pearsons’s correlations to examine relationships, regressions to build prediction equations, and finally used principal component analysis to help explain interconnected variables of dynamic strength and split jerk performance.
Figure 1. Study Procedures
Results
Near perfect correlations were found between back squat, overhead press, and split jerk (r=0.97). When breaking down each component, the overhead press and back squat demonstrated nearly perfect correlations (r=0.92) and (r=0.97) with the split jerk respectively. In this study, men and women showed similar correlations between exercises and split jerk performance.
From this analysis the authors created prediction equations where if you know your back squat and overhead press 1RM you can calculate the estimated split jerk 1RM. The equations are as follows:
Men – Split Jerk 1RM= -0.4566+ 0.6558* back squat 1RM + 0.2100* overhead press 1RM
Women- Split Jerk 1RM= -3.617+ 0.5814* back squat 1RM + 0.4809* overhead press 1RM
Discussion
This paper agreed with its hypothesis that greater overhead press and back squat strength would be related to split jerk performance. The secondary purpose was to examine male and female differences while generating prediction equations. This was achieved and provides good information for coaches regarding male and females split jerk performances.
Previous investigations have shown strong correlations between squatting and the snatch and clean (2,3). This current study, along with the author’s previous work, shed light on the relationship between strength of both the upper and lower-body and split jerk performance (4). In agreement with earlier studies looking at strength and performance, the combination of pressing strength and squatting strength underpin split jerk performance. This study revealed that by knowing the 1RM for the press and back squat you can explain 94% of the variance in the split jerk exercise. This indicates that athletes with higher absolute strength in the upper and lower body lift heavier weights in the split jerk.
When considering sex differences, earlier work by this group demonstrated lower correlations between the overhead press and split jerk with females compared to males. However, when the lower body strength from squatting was factored into the equation this finding was diminished. The current study showed nearly perfect correlations for men and women with the press, squat, and jerk. This makes sense in that the jerk is mainly a dynamic lower body exercise and the upper body provides secondary support by pressing under and stabilizing the bar. Nonetheless, based on this and earlier work shoulder strength should be a consideration for both male and female athletes and if this component is a weakness that may be holding back the split jerk more time should be dedicated to these training means.
Practical Applications
By testing your back squat and overhead press you can predict your split jerk performance. In addition, to elevate split jerk performance you can program exercises that may improve weaknesses in squatting and pressing. By knowing these relationships and ratios of strength to weightlifting performance coaches can better program training sessions to maximize performance.
References
1. Laputin, N. (2020). Managing the training of weightlifters. Sportivnypress.com
2. Stone, M. H., Sands, W. A., Pierce, K. C., Carlock, J. O. N., Cardinale, M., & Newton, R. U. (2005). Relationship of maximum strength to weightlifting performance. Medicine & science in sports & exercise, 37(6), 1037-1043.
3. Lucero, R. A., Fry, A. C., LeRoux, C. D., & Hermes, M. J. (2019). Relationships between barbell squat strength and weightlifting performance. International journal of sports science & coaching, 14(4), 562-568.
4. Soriano, M. A., Haff, G. G., Comfort, P., Amaro-Gahete, F. J., Torres-González, A., García-Cifo, A., ... & de Baranda, P. S. (2022). Is there a relationship between the overhead press and split jerk maximum performance? Influence of sex. International Journal of Sports Science & Coaching, 17(1), 143-150.
Study: The Relationship of Lower-Body, Multijoint, Isometric and Dynamic Neuromuscular Assessment Variables with Snatch, and Clean and Jerk Performance in Competitive Weightlifters: A Meta-Analysis
What assessments can reveal indicators of performance in competitive weightlifters? What can these measurements reveal about how we should prepare weightlifters for competition?
Introduction
Athlete testing and monitoring is a process of collecting data at various time points to evaluate how an athlete is adapting to a training process and to provide a snapshot of current physical capabilities. The sport of weightlifting has built in testing of current levels which is the one repetition maximum of the snatch and clean and jerk. However, frequent testing of these lifts or variations has some drawbacks, mainly the resulting fatigue from lifting maximal or near maximal loads. Therefore, coaches and scientists have developed proxy measures for performance which can reveal how an athlete is developing and what they may need in their training regime to maximize their total.
Some standard tests that are performed for weightlifters are dynamic assessments. These include strength measurements of 1 repetition maximum (1RM) front and back squats as well as lower body power assessments like the countermovement jump and static jump (1,2). These tests provide information related to maximal strength and muscular power output of the lower body. While vertical jumps are minimally fatiguing, 1RM squats suffer from similar drawbacks due to fatigue. For this reason, scientists often use isometric neuromuscular assessments such as the isometric mid-thigh pull to assess current capabilities. This test can provide information on maximal force generation capabilities, rate of force development abilities while being easily replicable and minimally fatiguing (3).
By understanding each of these assessments, coaches can learn where to place them into the training plan, how often to complete them, and what information each test provides. Each test provides slightly different information about the athlete’s physiology and can be embedded in the training plan to help better guide and direct the athletes development. The current article explores these various tests and how they relate to weightlifting performance.
Purpose
Meta-analyses are a statistical process that combines results from multiple similar studies to help answer questions about the current body of literature. In this specific study they attempt to review all studies related to lower body isometric and dynamic assessments and how they relate to competitive weightlifting performance.
Methods
These studies are slightly different than other experimental studies as they rely on the current literature to answer questions and synthesize data. First the authors outline their search criteria which include all the words below in table 1.
Table 1. Search Criteria
From here, the authors will screen, read, and clean up studies based on inclusion and exclusion criteria. They provided five inclusion criteria and two exclusion criteria which help to limit the studies to competitive weightlifters using original research and needed to provide correlations of data. Studies were excluded if they were not original research articles or if they scaled performance and did not provide raw maximal strength data.
Next the authors would grade the studies, examine their quality, and determine if any bias is present before beginning the statistical analysis. Following this, the authors conduct the meta-analysis based on relevant studies and broke certain groupings down into subcategories for further analysis.
Results
In the final analysis, 12 studies matched the criteria and resulted in 252 males and 143 females being included.
They broke down the analysis into the following sections:
Relationship between Countermovement Jump and Weightlifting Performance
Peak power had large to nearly perfect correlations with snatch and clean and jerk performance.
Relationship between Squat Jump and Weightlifting Performance
Peak power had large to nearly perfect correlations with snatch and clean and jerk performance.
Relationship between Isometric Mid-thigh pull and Weightlifting Performance
Peak force had very large correlations with snatch and clean and jerk performance
Force at 100ms and 200ms had large correlations to snatch and clean and jerk performance
Force at 250ms had very large correlations to snatch and clean and jerk performance
Early RFD correlated with snatch whereas later RFD was related to both snatch and clean and jerk
Relationship between Squats and Weightlifting Performance
Back squat and front squat show near perfect correlations between snatch and clean and jerk
Discussion
The main outcomes from this study were that jumps, squats, and isometric testing show strong to nearly perfect correlations with weightlifting performance in competitive lifters. Coaches can use this information when selecting a testing battery to measure and quantify an athlete’s current physiological state and to evaluate if a program worked as intended to improve their capabilities. Each test identified in this meta-analysis provides snapshots of various physical qualities needed for success in weightlifting.
Jumps
Various jumping tests are common in athletic testing and have been linked with multiple performance outcomes such as sprinting, change of direction, and general athletic abilities. In the case of weightlifting, better weightlifters tend to jump higher and more efficiently than lesser qualified athletes. While jump height is the outcome measure of the vertical jump test, the items underpinning this jump height may be more important for understanding training outcomes. As highlighted in the study, peak power from the squat and countermovement jump was strongly correlated to performance. This is due to the similar joint actions involved in jumping and the weightlifting movements. Peak power is the intersection of both force and velocity which is also critical for weightlifting performance. Outside of this, the impulse-momentum relationship is critical to jumping in that the final velocity before the athlete leaves the ground determines the jump height. Impulse- being force times time- is important for weightlifting as there is limited time to impart force into the barbell to overcome inertia and achieve the necessary speeds for a successful lift. For these reasons vertical jumping and its underlying constructs serve as a low fatigue measure of physiological abilities.
Squats
There has been good evidence from the Soviet Union that squatting movements provide strong correlations to the weightlifting movements. In their early work the provide ratios that show when an athlete is efficient the relationship between squatting and the snatch and clean and jerk. Later evidence has demonstrated very strong correlations between squatting strength and snatch, clean and jerk, and the total weight lifted. Squatting is an expression of force production and the greater the force you can produce sets a limit or ceiling on the maximal force you can generate with the lower body. Barring any technical limitations, the lifter who can produce the most force in the correct amount of time associated with the lifts (~1 second) that athlete will lift the most amount of weight. Assuming most athletes at the elite level have elite technique, this leaves force production and bar velocity as the trainable qualities that will discriminate lifters at the highest levels. Much effort in training is dedicated to building the squat for good reason and this helps to improve the force production capabilities of the lower extremities which combined with proper velocity execution leads to greater peak power production which underpins weightlifting performance.
Isometric Testing
While common in laboratory studies, isometric mid-thigh pulls are less commonly found in field-based assessments. This test involves pulling against an immovable bar above force plates to examine the maximal force capabilities during an isometric movement and several force-time characteristics associated with that maximal effort. When this test is done correctly it mimics similar joint angles that are found in the second pull of the weightlifting movements. With isometric strength being slightly greater than concentric force production this serves as the upper limit of achievable force production by an athlete. The first aspect is the peak force value which is the highest achieved force regardless of time in this test. In general, the better the weightlifter the better the force production in this test. Next, would be the time dependent measures of force production in various time windows (100, 200, 250ms) and the rate of force development in those windows. These additional measures show how rapidly and how much force an athlete can produce at different time points which may be related to various phases of the lift. From the current analysis early force characteristics had lower correlations than later time windows and peak force. This is likely due to the nature of the test and the lower trainability of early phase characteristics. The benefit of this testing is that it is highly reliable, valid, and minimally fatiguing when used by trained athletes. For this reason it is well placed to measure force-time characteristics in this population.
Practical Applications
This investigation provided data on four major categories of testing and monitoring for weightlifting. This information demonstrates the relationship between these tests and weightlifting performance. This provides coaches with evidence-based correlation values for various tests that underpin physiological variables related to the sport of weightlifting. With this knowledge coaches can use these testing batteries to measure various physical qualities to help develop better programs to maximize an athlete’s strengths while mitigating their weaknesses and removing bottlenecks in physical development.
References
1. Carlock, J. M., Smith, S. L., Hartman, M. J., Morris, R. T., Ciroslan, D. A., Pierce, K. C., ... & Stone, M. H. (2004). The relationship between vertical jump power estimates and weightlifting ability: a field-test approach. The Journal of Strength & Conditioning Research, 18(3), 534-539.
2. Stone, M. H., Sands, W. A., Pierce, K. C., Carlock, J. O. N., Cardinale, M., & Newton, R. U. (2005). Relationship of maximum strength to weightlifting performance. Medicine & science in sports & exercise, 37(6), 1037-1043.
3. Beckham, G., Mizuguchi, S., Carter, C., Sato, K., Ramsey, M., Lamont, H., ... & Stone, M. (2013). Relationships of isometric mid-thigh pull variables to weightlifting performance. J Sports Med Phys Fitness, 53(5), 573-581.
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