Abstract
n the strength and conditioning field, a variety of training exercises are being applied to improve speed-related performance, but there is a lack of traditional strength training guides that can be used for training effectiveness. The aim of this study was to assess the impact of a six-week traditional strength training program on elite rugby players and explore the relationships between the one repetition maximum (1RM) of traditional strength exercises and athletic performance. Twenty elite rugby players (age = 30.5±1.5 years, mass = 96.7±16.6 kg, height = 179.3±6.0 cm) completed the strength training program, and 1RM values for bench press, squat, deadlift, and power clean, along with athletic performance metrics (20 m and 40 m sprints, vertical jump, broad jump, Bronco test, L-run), were measured before and after the training period. Medium effect sizes were observed in the deadlift (p= 0.04, d = 0.49) and bench press (p= 0.019, d = 0.57) 1RM, while the squat exhibited a very large effect size (p< 0.001,
clean, along with athletic performance metrics (20 m and 40 m sprints, vertical jump, broad jump, Bronco test, L-run), were measured before and after the training period. Medium effect sizes were observed in the deadlift (p= 0.04, d = 0.49) and bench press (p= 0.019, d = 0.57) 1RM, while the squat exhibited a very large effect size (p< 0.001, d = 2.08). Both before and after training, greater power clean 1RM demonstrated a strong correlation with each athletic performance test. However, bench press 1RM, both pre-and post-training, did not significantly associate with functional performances (p> 0.05). Notably, power clean 1RM showed the strongest correlation with athletic performance; despite being the most significant improvement in squat 1RM after the six-week training period, it was not associated with athletic performance outcomes in rugby players. This study underscores the varied impact of specific strength exercises on athletic performance, emphasizing the distinct role of power clean 1RM in predicting speed-related performance in male rugby players. Keywords:bench press; power clean; rugby conditioning; strengthening; athletic training; strength assessment 1. Introduction Rugby is a physically demanding sport that requires a combination of physical at- tributes such as proficiency in body contact, sprinting capability, and agility. These at- tributes are essential for high-intensity sports activities [1] and contribute significantly to optimal performance against competitors. In the past two decades, conventional strength training methods such as deep squat, deadlift, clean, and bench press have faced skepticism as outdated techniques. On the one hand, training methodologies increasingly incorporate exercises aimed at injury prevention, such as movement screening or rubber resistance exercises [2,3]. In recent years, with the development of sports technology, there has been a growing reliance on machine-measured data [4]. While these technological advances have their benefits, they tend to make conventional strength training less important. How- ever, research argues that high-intensity traditional strength training, widely viewed as antiquated, can still produce favorable outcomes in readying athletes for unpredictable Appl. Sci.2024,14, 31.
tend to make conventional strength training less important. How- ever, research argues that high-intensity traditional strength training, widely viewed as antiquated, can still produce favorable outcomes in readying athletes for unpredictable Appl. Sci.2024,14, 31.
Appl. Sci.2024,14, 31 2 of 10 sports scenarios [5]. Specifically, it enhances neural activity, increases the rate of force development, and effectively produces power [6,7]. In addition, these trainings elevate muscle firing rates and motor unit activities through calcium regulation in the sarcoplasmic reticulum [8]. Previous research suggests that traditional strength training has a positive impact on rugby performance [9,10]. Several studies have examined training methods for improving sports performance. Hartmann et al. [11] discovered that strength training, based on a periodization model, generated a potentiation effect on strength and speed-strength, which lasted for48–148 h. Participants who showed higher squat [12] and bench press [13] capacities achieved quicker sprint times, indicating a favorable association between conventional strength training and speed performance. Swinton (2014) discovered that athletes with exceptional deadlift records had better performance in the 505 agility test, which is critical in tactical sports such as rugby [14]. Variations in performance outcomes have been observed based on instructional differences or training execution, despite numerous studies emphasizing the beneficial effects of traditional strength training [15]. Identifying the most effective strength training tool for maximizing performance becomes crucial in achieving the specific goals of strength training for athletes, poten- tially outweighing the adoption of various training methods. Therefore, prioritizing the identification of the optimal strength training tool is imperative for athletes seeking to enhance their performance. However, there is a lack of information regarding which tradi- tional strength training methods coaches should select for their strengthening programs, as there is no consensus on the optimal strength assessment based on previous investi- gations [11–14]. Therefore, this investigation aimed to evaluate the effect of six weeks of traditional strength training and to identify the relationships between the improvement of speed related performance and each strengthening exercise. To accomplish this aim, we hypothesized that six weeks of traditional strength training would improve speed-related performance in male rugby players and that improvements in squat and power clean would correlate with improved speed-related performance. The study outcomes can be a significant indicator for evaluating the impact of strength testing on enhancing sports performance. Furthermore, a close connection
strengthening exercise. To accomplish this aim, we hypothesized that six weeks of traditional strength training would improve speed-related performance in male rugby players and that improvements in squat and power clean would correlate with improved speed-related performance. The study outcomes can be a significant indicator for evaluating the impact of strength testing on enhancing sports performance. Furthermore, a close connection between specific strength training exercises and performance enhancement can offer valuable insights for strength conditioning coaches seeking to design effective strength programs. 2. Materials and Methods 2.1. Participants Twenty elite-level rugby players participated in the current study, voluntarily. The participants had an average age of 30.5±1.5 years, a body mass of 96.7±16.6 kg, and a height of 179.3±6.0 cm. An a priori power analysis using G*power was conducted to determine the minimum number of participants required. Effect size calculations were based on a comprehensive review of various studies demonstrating improvements in athletic performance after strength training, indicating medium to large effect sizes [16]. Nineteen participants, at minimum, were deemed necessary to observe a medium-large effect size (Cohen’s d = 0.8) at an alpha level of 0.05, with a power (1 –β) of 0.8. Participants were elite rugby players currently playing for the professional team, and all data were collected from players who agreed to participate in the study. Players were eligible to participate in the study if they were a member of the team but were excluded if they were unable to participate in the strength testing and training due to an injury within the last three months. In addition, those who used drugs, medications, or dietary supplements for performance-enhancement purposes were omitted as part of the exclusion criteria. The Institutional Review Board of the University approved the study protocol, and all participants provided written informed consent.
Appl. Sci.2024,14, 31 3 of 10 2.2. Procedure This study utilized a cross-sectional design, as depicted in Figure. Participants underwent diverse tests during pre-testing sessions that spanned three days. Uniformly scheduled testing sessions were implemented to minimize the potential impact of circadian rhythms, with all participants receiving standardized meals on the day of testing. Pre- and post-testing procedures were administered consistently throughout the study.Appl. Sci. 2024, 14, x FOR PEER REVIEW 3 of 10 2.2. Procedure This study utilized a cross-sectional design, as depicted in Figure 1. Participants un- derwent diverse tests during pre-testing sessions that spanned three days. Uniformly scheduled testing sessions were implemented to minimize the potential impact of circa- dian rhythms, with all participants receiving standardized meals on the day of testing. Pre- and post-testing procedures were administered consistently throughout the study. Figure 1. Study procedure: RM, repetition maximum. 2.3. 1RM Test The 1RM testing procedures adhered to guidelines set by the National Strength and Conditioning Association (NSCA) [17] and were overseen by a strength & conditioning (S&C) coach accredited by the World Rugby S&C. On the day of the 1RM test, participants completed the bench press, squat, deadlift, and power clean in a random order following explicit instructions outlined in the testing protocol. Prior to the 1RM testing, a standard- ized 15-min dynamic warm-up was conducted. Subsequently, participants performed a submaximal warm-up lifting session for all exercises, which consisted of five sets (repeti- tions: 8, 3, 1, 1, and 1; intensity: 50, 70, 80, 90, and 100% of estimated 1RM), as referenced in [18]. Between trials, a rest period of 3 mins was granted, with a 5-min break given be- tween exercises following the 1RM test [19]. All 1RM information collected was normal- ized based on body weight to conduct subsequent analysis [20]. 2.3.1. Bench Press Participants conducted the bench press on a strong bench located within the power rack (Respect Athlete, Mokpo, Republic of Korea). They were permitted to choose their own grip and width, before lifting the barbell and lowering it to approximately 3 cm above the xiphoid process. After lightly touching the barbell
body weight to conduct subsequent analysis [20]. 2.3.1. Bench Press Participants conducted the bench press on a strong bench located within the power rack (Respect Athlete, Mokpo, Republic of Korea). They were permitted to choose their own grip and width, before lifting the barbell and lowering it to approximately 3 cm above the xiphoid process. After lightly touching the barbell to their chest, they fully extended their elbows and pushed the barbell upward. Participants were directed to coordinate their hip movement with the extension of their elbow, and any attempt where the barbell bounced off the chest was excluded. 2.3.2. Squat Participants performed squats using an Olympic barbell (XPodium, Cheonan, Re- public of Korea) in a high-bar position within a power rack. The squat descent ended when the thigh was parallel to the ground, with subsequent return to the starting position. A strength and conditioning coach monitored squat depth laterally to the power rack, while safety bars were positioned 5–10 cm below the lowest point of the movement to prevent injury. Figure 1.Study procedure: RM, repetition maximum. 2.3. 1RM Test The 1RM testing procedures adhered to guidelines set by the National Strength and Conditioning Association (NSCA) [17] and were overseen by a strength & conditioning (S&C) coach accredited by the World Rugby S&C. On the day of the 1RM test, participants completed the bench press, squat, deadlift, and power clean in a random order following ex- plicit instructions outlined in the testing protocol. Prior to the 1RM testing, a standardized 15-min dynamic warm-up was conducted. Subsequently, participants performed a submax- imal warm-up lifting session for all exercises, which consisted of five sets (repetitions: 8, 3, 1, 1, and 1; intensity: 50, 70, 80, 90, and 100% of estimated 1RM), as referenced in [18]. Between trials, a rest period of 3 mins was granted, with a 5-min break given between exercises following the 1RM test [19]. All 1RM information collected was normalized based on body weight to conduct subsequent analysis [20]. 2.3.1. Bench Press Participants conducted the bench press on a strong bench located within the power rack (Respect Athlete, Mokpo,
referenced in [18]. Between trials, a rest period of 3 mins was granted, with a 5-min break given between exercises following the 1RM test [19]. All 1RM information collected was normalized based on body weight to conduct subsequent analysis [20]. 2.3.1. Bench Press Participants conducted the bench press on a strong bench located within the power rack (Respect Athlete, Mokpo, Republic of Korea). They were permitted to choose their own grip and width, before lifting the barbell and lowering it to approximately 3 cm above the xiphoid process. After lightly touching the barbell to their chest, they fully extended their elbows and pushed the barbell upward. Participants were directed to coordinate their hip movement with the extension of their elbow, and any attempt where the barbell bounced off the chest was excluded. 2.3.2. Squat Participants performed squats using an Olympic barbell (XPodium, Cheonan, Republic of Korea) in a high-bar position within a power rack. The squat descent ended when the thigh was parallel to the ground, with subsequent return to the starting position. A strength and conditioning coach monitored squat depth laterally to the power rack, while safety bars were positioned 5–10 cm below the lowest point of the movement to prevent injury. 2.3.3. Deadlift Participants utilized the customary technique for performing the deadlift exercise, using a grip they personally chose (excluding the reverse grip). Once the grip was chosen, it remained constant throughout the post-testing session. Starting from a position where
Appl. Sci.2024,14, 31 4 of 10 the feet were separated by approximately shoulder-width and the hips were between the shoulder and knee height, the participants were directed to extend their knee and hip, raising the barbell off the ground until it was in an upright position [21]. 2.3.4. Power Clean During the power clean evaluation, participants assumed a self-selected grip and situated themselves in front of the Olympic barbell. In the initial pull, the hips and knees were forcefully extended to raise the barbell from the floor. After that, the subjects propelled their hips forward in preparation for the second pull. By employing a dynamic extension of their hips, knees, and ankles, participants seamlessly moved into the catching phase with a partial squat position. This detailed process aims to enhance the production of explosive power necessary for the effective implementation of the power clean. 2.4. Performance Test 2.4.1. 20 m/40 m Sprint Test Performance tests were conducted 48 h after the 1RM tests, preceded by a 10-min standardized warm-up. In the 20 m and 40 m sprint tests, subjects assumed a 2-point starting position without the use of starting blocks. Positioned on the starting line, subjects initiated the sprint explosively upon the strength and conditioning (S&C) coach’s whistle. Each participant underwent two sprint trials, and the best recorded time was selected for analysis. An automatic timing gate (Daewoo Sports Industry, Seoul, Republic of Korea) was employed to record the times, with a 90 s resting interval between trials. The 20 m sprint and 40 m sprint were completed as separate components of the testing protocol (Figure).Appl. Sci. 2024, 14, x FOR PEER REVIEW 4 of 10 2.3.3. Deadlift Participants utilized the customary technique for performing the deadlift exercise, using a grip they personally chose (excluding the reverse grip). Once the grip was chosen, it remained constant throughout the post-testing session. Starting from a position where the feet were separated by approximately shoulder-width and the hips were between the shoulder and knee height, the participants were directed to extend their knee and hip, raising the barbell off the ground until it
grip they personally chose (excluding the reverse grip). Once the grip was chosen, it remained constant throughout the post-testing session. Starting from a position where the feet were separated by approximately shoulder-width and the hips were between the shoulder and knee height, the participants were directed to extend their knee and hip, raising the barbell off the ground until it was in an upright position [21]. 2.3.4. Power Clean During the power clean evaluation, participants assumed a self-selected grip and sit- uated themselves in front of the Olympic barbell. In the initial pull, the hips and knees were forcefully extended to raise the barbell from the floor. After that, the subjects pro- pelled their hips forward in preparation for the second pull. By employing a dynamic extension of their hips, knees, and ankles, participants seamlessly moved into the catching phase with a partial squat position. This detailed process aims to enhance the production of explosive power necessary for the effective implementation of the power clean. 2.4. Performance Test 2.4.1. 20 m/40 m Sprint Test Performance tests were conducted 48 h after the 1RM tests, preceded by a 10-min standardized warm-up. In the 20 m and 40 m sprint tests, subjects assumed a 2-point start- ing position without the use of starting blocks. Positioned on the starting line, subjects initiated the sprint explosively upon the strength and conditioning (S&C) coach’s whistle. Each participant underwent two sprint trials, and the best recorded time was selected for analysis. An automatic timing gate (Daewoo Sports Industry, Seoul, Republic of Korea) was employed to record the times, with a 90 s resting interval between trials. The 20 m sprint and 40 m sprint were completed as separate components of the testing protocol (Figure 2). Figure 2. Illustration of 20 m/40 m sprint test. 2.4.2. Vertical Jump The vertical jump test utilized the Vertec. The starting point for each jump was deter- mined by extending the hands to the highest reachable distance. Subsequently, partici- pants were instructed to execute a maximal jump, and the highest point achieved was recorded [22]. Two trials of the vertical jump
2. Illustration of 20 m/40 m sprint test. 2.4.2. Vertical Jump The vertical jump test utilized the Vertec. The starting point for each jump was deter- mined by extending the hands to the highest reachable distance. Subsequently, partici- pants were instructed to execute a maximal jump, and the highest point achieved was recorded [22]. Two trials of the vertical jump were conducted with a 30 s interval between attempts, and the best score was utilized for analysis. 2.4.3. Broad Jump The broad jump was conducted on the floor using a tape measure. Participants posi- tioned themselves on the starting line with both feet and initiated a forward jump with bent knees, utilizing arm swing for support [23]. Two trials of the broad jump were com- pleted, separated by a 30 s interval. The best score obtained was selected for analysis. Figure 2.Illustration of 20 m/40 m sprint test. 2.4.2. Vertical Jump The vertical jump test utilized the Vertec. The starting point for each jump was determined by extending the hands to the highest reachable distance. Subsequently, par- ticipants were instructed to execute a maximal jump, and the highest point achieved was recorded [22]. Two trials of the vertical jump were conducted with a 30 s interval between attempts, and the best score was utilized for analysis. 2.4.3. Broad Jump The broad jump was conducted on the floor using a tape measure. Participants positioned themselves on the starting line with both feet and initiated a forward jump with bent knees, utilizing arm swing for support [23]. Two trials of the broad jump were completed, separated by a 30 s interval. The best score obtained was selected for analysis. 2.4.4. L-Run The L-run involved placing three cones in an L-shaped configuration, each 5 m apart. Participants commenced the run explosively upon the starting whistle, progressing for- ward and executing a left turn at the second cone. At the third cone, a right-sided turn was performed before returning to the second cone and finally back to the starting line. Participants were directed to complete the course as swiftly as possible [24]. Running times
5 m apart. Participants commenced the run explosively upon the starting whistle, progressing for- ward and executing a left turn at the second cone. At the third cone, a right-sided turn was performed before returning to the second cone and finally back to the starting line. Participants were directed to complete the course as swiftly as possible [24]. Running times were recorded using an automatic timing gate (Figure). Two L-run trials were completed with a 2 min interval between attempts, and the best score was chosen for analysis.
Description
The study evaluates strength training effects on rugby performance.