Because powerlifting continues to use novel methods to improve strength, many powerlifters have adopted specialty bars into their training regimens (38). The potential benefits of these new techniques have come under scrutiny of scientific study (4,6,31). In particular, some specialty bars, such as the Tsunami Bar (Tsunami Bar LLC, West Columbia, SC, USA) or Earthquake Bar (Bandbell, Inc., Columbus OH, USA), are more flexible than traditional bars, which adds an element of unstable load (UL) during resistance exercise. Bars that use UL technology add variety into a training regimen but may also directly benefit lifters by increasing the activation of stabilizing muscles (31), improving exercise technique (27), and increasing neuromuscular control (29). There are a variety of methods to integrate UL into training, including altering the barbell itself (4,31), changing the distribution of the load on the barbell (11), or simply using dumbbells (23) instead of traditional straightbars. To date, findings on the effectiveness of these UL modifications are mixed (4,6,11,31).
One study found that use of UL increased muscle activation for the prime movers in the bench press exercise at 40% one repetition maximum (1RM) intensity in a sample of collegiate athletes when compared with traditional barbell (TB) exercise (20). In a sample of football players, the Tsunami Bar increased lower-body power after a 5-week training intervention with a 125-lb intensity when performing squats, clean and press, bench press, and barbell jammers compared with a TB loaded at 45–60% 1RM intensity (6).
Although some studies have showed a benefit to UL training, other studies have shown that there is a decrease in activation (31) or no change (11) in the prime mover musculature. Similar to the findings from unstable surface training (3), this lack of positive change in the target muscle may not produce enough stimuli to induce strength adaptations. In a sample of recreationally trained men, the UL training that used the Tsunami Bar was not more effective than a TB for force production in the bench press at loads across 40–80% 1RM (4).
Some have suggested that flexible barbells can be used to improve technique (27). Lawrence et al. (27) suggest that the Earthquake Bar may facilitate better execution of specific coaching cues, such as “stay tight,” which ultimately will improve force production and eliminate unwanted barbell movement. The perturbations of the barbell during the repetitions of the bench press require the lifter to maintain tightness throughout the lift, thus preventing muscles from becoming lax, which enhances the lifter's stability throughout performance of the task (27).
Recently, the Freak Bar (FB; Westside Barbell, Columbus, OH, USA) has been developed as a novel specialty bar for UL. The FB is a metal barbell with components of instability that can be loaded in a manner comparable with a TB. The FB is a patent-pending loaded exercise barbell (20 kg) that allows for pushing and pulling the barbell on the horizontal axis, with external resistance provided from springs (Figure 1). The straight-coiled helix compression springs provide additional resistance through horizontal adduction and abduction of the shoulder during resisted movements. The lateral-medial resistance provided by the spring for the FB may facilitate the common bench press coaching cue to “rip the bar apart” while pressing during the concentric phase. Duffey et al. (10) reported that, in the bench press, approximately 25% of force applied to the barbell is in the lateral direction. Thus, teaching the lifter to produce force laterally along the barbell during the bench press may have benefit for the barbell's overall vertical force by increasing muscle engagement, including the triceps brachii, which also serve to execute the bench press task (10).
Because of the multiple forms and variations of UL, the applications of this training method remain unclear. The few studies on the effects of specialty bars are limited by a short duration of training, generally only 3 to 4 testing sessions, in which muscle activation (11,20,31) or force production (4) have been measured. Only 1 study has examined a training intervention longer than 5 weeks (6), which is a more common training period to induce activation and force changes. Thus, the purpose of this study was to evaluate the effects of a 6-week training program using the FB for the bench press exercise in a sample of collegiate powerlifters. We hypothesized that the FB and TB groups would increase maximum upper-body strength at the end of the 6-week training intervention. We also hypothesized that both groups would increase isometric peak force production at 3 bench press positions: (a) presticking, (b) sticking, and (c) poststicking points at the conclusion of the 6-week intervention. Two potential benefits of UL training are an increase in activation of the stabilizer muscles (29,31) and the teaching of the lifter to maintain stability (27). The instability components of the FB may provide a training adaptation that allows the lifter to maintain peak tension for a given time interval. Therefore, we hypothesized that the FB group would produce a greater isometric peak impulse compared with the TB group at each bench position after training intervention.
Experimental Approach to the Problem
A repeated-measures experimental design was performed to compare the pretraining and posttraining mean values for maximum strength, peak force, and peak impulse production in a sample of competitive powerlifters. Peak force and peak impulse were measured at 3 bench positions, defined by the distance of the barbell from the chest during the concentric phase of the bench press. Subjects were matched by closest value for 1RM bench to control for pre-existing differences in bench press strength, and then matched pairs were randomly assigned to either group using a coin flip. Subjects included 10 collegiate club powerlifters who were randomly assigned to 2 groups of 5: FB (n = 5) and TB (n = 5). Both groups engaged in the same 6-week strength training program, except for the bench press exercise on the second upper-body day of the week (Thursday). One group used the FB (FB group), whereas the other used a TB (TB group) for the bench press regimen. The dependent variables were 1RM bench press, isometric peak force, and isometric peak impulse at 3 bench positions. The independent variable was the barbell (FB or TB).
Ten competitive powerlifters were recruited from the university's powerlifting club team to participate in the study, and were randomly assigned to either the FB group (1 woman and 4 men; mean ± SD 21.0 ± 2.7 years; 173.7 ± 12.5 cm) or the TB group (2 women and men; 21.8 ± 1.3 years; 170.6 ± 10.2 cm). All subjects were raw powerlifters and had competed in at least one powerlifting competition. Inclusion criteria were (a) being between the ages of 18 and 35; (b) being an active member of the team (having weekly training sessions for at least 1 year); (c) being free of any physical limitations, defined as having no upper-body musculoskeletal injuries that affected the bench press exercise; and (d) having at least 2 years of resistance training experience. The exclusion criterion was having a musculoskeletal upper-body injury that affected the bench press exercise or isometric bench press force output test.
All subjects were familiar with the bench press exercise and performed the bench press at least once per week. All subjects in the FB group underwent a familiarization trial with the FB before the start of the training program. Before enrollment, all subjects completed the Physical Activity Readiness Questionnaire and a medical and activity history questionnaire. After an explanation of all procedures, risks, and benefits, each subject provided his or her written informed consent before participation in this study. The research protocol was approved by the Hofstra University Institutional Review Board before subject enrollment.
Maximal Strength Testing
Before the 6-week training intervention, all subjects established a 1RM and maximum isometric force output in the bench press exercise. Before maximal strength testing, subjects performed a standardized warm-up that consisted of 5 minutes on a cycle ergometer against a light resistance, followed by light-resistance shoulder exercises (i.e., internal/external dumbbell rotations and light band scaption) to prepare for the bench press. The 1RM test for the bench press was performed using methods described by the National Strength and Conditioning Association (37). Each subject performed 2 warm-up sets, using a resistance of approximately 40–60% and 60–80% of his or her perceived maximum. Subjects then performed 3 to 4 attempts of the bench press to determine their 1RM. A 3- to 5-minute rest period was provided between each attempt. All 1RM attempts were completed under the supervision of a certified strength and conditioning specialist (CSCS). The bench press was performed with a conventional shoulder width grip, and a successful lift required the participant to lower the bar until it lightly touched the chest (i.e., subjects were not permitted to bounce the bar off of the chest) before lifting the bar back to a straight-arm position with the hips and feet remaining in contact with the bench and floor, respectively, throughout the lift. Attempts that did not meet the range of motion criteria for each exercise or that did not involve proper technique were discarded.
Peak Force and Peak Impulse for Isometric Testing
All force output was recorded using a force plate (Vernier Software and Technology, Beaverton, OR, USA) sampling at 1,000 Hz and a data collection computer using Logger Pro 3 software (Vernier Software and Technology). Isometric bench press sets were performed on a steel-plated squat rack against immovable plated safety catch bars with minimal padding. The force plate was mounted (Figure 2) on the safety catch bars to ensure transference of the force to Go Link sensor (Vernier Software and Technology) acquisition system for further analysis. This established a flush contact of the barbell to the plate, and a Bench Blokz (Bench Blokz, Ruckersville, VA, USA) was used and attached to the end of the 20-kg Olympic barbell (Figure 2).
Forty-eight hours after maximal strength testing, subjects performed the isometric bench press test, using methods that are similar to those of previous research (7). Subjects pressed a 20-kg Olympic barbell into the mounted force plate for maximum effort at each of the bench positions. The 3 positions (Figure 3) for the isometric strength testing consisted of the barbell's being 0–1 cm from the chest, 5–7 cm from the chest, and 18–20 cm from the chest. These points are the presticking point, sticking point, and poststicking point, respectively, for the bench press exercise (43).
A 5-second ramp protocol (2-second ramp and 3-second maximum voluntary contraction) was performed 3 times at each range of motion position for the isometric tests. This protocol was used to avoid the risk of injury because a rapid contraction against a fixed load has been documented to result in shoulder injury in athletic populations (22). Subjects performed three 5-second trials at each position, and the highest force output of the 3 sets was recorded. Peak impulse was calculated by taking the integral of the force time graph for the 1-second period after peak force has been reached (Figure 4). This ensured that all time intervals were equal for each subject.
To examine the reliability of the force plate, we calculated intraclass correlation coefficients (ICCs) for pretesting and posttesting sessions. Each subject performed 3 trials of the 5-second isometric bench press test at each of the 3 bench positions. Average-measures ICCs were calculated at each position. The ICCs for positions 1, 2, and 3 for the pretesting session were 0.991 (CI, 0.975–0.998), 0.993 (CI, 0.979–0.998), and 0.998 (CI, 0.994–0.999), respectively. The ICCs for positions 1, 2, and 3 for the posttesting session were 0.983 (CI, 0.922–0.996), 0.944 (CI, 0.808–0.989), and 0.993 (CI, 0.966–0.998), respectively.
Subjects in the FB group trained with the FB 1 session per week for 6 weeks, for a total of 6 sessions. The 6-week program was similar in exercise selection and training practices to other powerlifting programs that focus on the back squat, deadlift, and bench press exercises with a blend of assistance exercises, such as the close grip bench press (40). The program also was similar in squat and bench press frequency (2 sessions/week) (18) and duration (6-weeks) (45) to other traditional powerlifting training programs. Table 1 presents a more detailed description of the training intervention. All training sessions were performed in the Hofstra Fitness Center at Hofstra University under CSCS supervision. The weight room was equipped with 2 bench press stations and ample space to train and test all subjects concurrently.
The training intervention required lifting sessions 5 days a week for 6 weeks. Subjects performed lower-body exercises on Tuesdays, Fridays, and Sundays and upper-body exercises on Mondays and Thursdays. Subjects typically performed 5–6 exercises per session, focusing primarily on free-weight dynamic exercises that incorporate all major muscle groups, such as competition squats, competition deadlifts, competition bench presses, bench press variations, dynamic upper-back exercises, tricep extensions, and core exercises. Assisted lower-body exercises typically comprised hip extension/flexion and glute-hamstring raises.
All subjects performed the same workout, except for the bench press exercise, on the second upper-body day of the week (Thursday). On Thursday, the FB group used the FB during the 3-position pause bench press exercise. This style of training is a common practice for powerlifters because, per the rules of the USAPL competition bench, lifters are required to hold the barbell at a motionless pause on the chest before a chief referee signals a press command (19). The traditional group performed the 3-position pause bench press exercise with a TB. For the FB group, the 3-position pause bench press exercise was performed by a controlled lowering of the barbell during the eccentric phase, followed by an isometric hold at the respective joint position and a squeezing of the springs for 2 repetitions at each position. For each of the 3 positions, the lifters were instructed to “squeeze” and “spread” the handles on the FB from a normal position grip to a narrow position grip (Figure 5) on the barbell. The spring-loaded 2 × 4 inch handgrip (Figure 1) allowed for movement along the barbell in the lateral direction. For the TB group, subjects also were instructed to perform the 3-position pause bench press exercise with a controlled lowering of the barbell in the eccentric phase and a pause at each of the 3 bench positions. For both groups, during the concentric phase, subjects pressed the barbell as quickly as possible to replicate a typical bench pressing movement (30). This cadence is commonly used for specialty barbells with components of instability (31).
The initial loading for the 3-position pause bench press, using the FB, was 60% of subjects' current 1RM for the bench press. Subjects used an autoregulated approach based on weekly performance, which resulted in the loading's being kept the same or having a 5-lb increment progression. This loading progression is similar to what has been reported in the literature (45). The initial loading percentage was chosen during pilot testing, when several advanced-level lifters performed a near-maximal effort set of 3 repetitions with the FB and then compared that weight against their competition maximum. This prescribed load is consistent with the methods used by Ostrowski et al. (31) and Dunnick et al. (11) that used UL for the barbell bench press.
Subjects were advised to maintain their normal diet and to avoid taking any supplements during the study. Self-reported food records were collected during the first (week 1) and final week (week 6) of the study. Subjects were instructed on how to properly complete a 3-day dietary recall log to include all food items and their respective portion sizes consumed. Dietary analysis software (myfitnesspal) was used to analyze dietary recalls to assess potential differences in total energy and macronutrient intake between groups (Table 2).
Data analysis was performed using IBM SPSS, Version 24.0 (SPSS, Inc., Chicago, IL, USA) software for Windows. Descriptive data for subject characteristics and experimental variables were calculated as mean values and SDs. Normality of the distributions was tested using a Shapiro-Wilk test (p ≤ 0.05). All the data satisfied normality. To test for pre-existing differences before the program (Table 3), we used independent t-tests to examine the difference between the groups for body weight, 1RM bench press, and peak force.
Dependent t-tests were used to calculate within-group differences between pretest and posttest scores for 1RM bench press, peak force at 3 positions, and peak impulse at 3 positions. For the 1RM bench press test, a 1-way analysis of covariance (ANCOVA) was used to examine the difference between the groups, with the bench press delta score as the dependent variable, group as the fixed factor, and pretest bench press score as the covariate. The homogeneity of regression assumption tested for the interaction between the group and pretest bench press score. For peak force and peak impulse, a 1-way multivariate ANCOVA was used to examine differences between the groups, with all 3 position delta scores as the dependent variables, group as the fixed factor, and pretest scores as the covariate. If a significant Wilks lambda was found, individual 1-way analysis of variances were calculated to examine the differences between the groups for the respective dependent variable. The homogeneity of regression assumption tested for the interaction between the group and pretest delta scores for each peak force and peak impulse position. The multicollinearity assumption was tested using collinearity diagnostics and an examination of the variance inflation factor (VIF) across the 3 peak force delta scores and 3 peak impulse delta scores. A VIF >10 was a violation for this assumption.
As per Beck (2), a priori sample size was calculated for a 1-way ANCOVA with the pretest 1RM bench press as a covariate. To detect a potential moderate 1.4 Cohen's d effect size for recreationally trained (32) subjects at the α = 0.05 significance level, a total sample size of 10 subjects, 5 per group, produced an actual power of 0.51. All subjects were familiar with the powerlifting program and had been training consistently for ≥2 years; however, as a group, they were classified as recreationally trained due to the overall team's modest bench press per body weight (BP/BW) 1RM score of 1.18.
Both groups demonstrated 100% compliance to the training program. Raw data values, delta scores, post-1RM bench press per body weight scores, and within-group Cohen d effect sizes for maximum 1RM bench press strength are presented for each training group in Table 4. Cohen's d within-group effect size was calculated by the difference between pretest and posttest scores, divided by the SD of the pretest (8).
One Repetition Maximum Bench Press
Individual spaghetti graphs are presented for each subject as a result of the 6-week training program (Figure 6). There was no significant difference between the groups across delta score, using pretest bench press as a covariate (p = 0.589, = 0.044). There was a significant (p = 0.006) increase for the FB group before (100.9 ± 41.6 kg) and after (107.7 ± 43.2 kg) training intervention. There was a nonsignificant (p = 0.23) increase for the TB group before (105.9 ± 53.2 kg) and after (110.4 ± 55.9 kg) training intervention.
There were no significant differences in peak force between the groups for bench position 1 (p = 0.183, = 0.323), position 2 (p = 0.360, = 0.169), or position 3 (p = 0.702, = 0.032). There was a nonsignificant increase for the FB group before and after training intervention for position 1 (mean difference 57.6 ± 61.1, p = 0.103), position 2 (mean difference 69.4 ± 118.7, p = 0.26), and position 3 (mean difference 115.4 ± 123.5, p = 0.105). There was a nonsignificant decrease for the TB group before and after training intervention for position 1 (mean difference −35.6 ± 78.0, p = 0.365) and position 2 (mean difference −31.8 ± 64.4, p = 0.332) as well as a significant increase for position 3 (mean difference 81.4 ± 36.1, p = 0.007) (Figure 7).
Figure 8 illustrates peak impulse output by bench press position across both groups, before and after training intervention. There were no significant differences in peak impulse between the groups for bench position 1 (p = 0.184, = 0.322), position 2 (p = 0.321, = 0.195), or position 3 (p = 0.667, = 0.040). There was a nonsignificant increase for the FB group before and after training intervention for position 1 (mean difference 74.7.6 ± 71.1, p = 0.078), position 2 (mean difference 81.3 ± 115.8, p = 0.191), and position 3 (mean difference 113.8 ± 120.0, p = 0.101). There was a nonsignificant decrease for the TB group before and after training intervention for position 1 (mean difference −29.4 ± 86.2, p = 0.487) and position 2 (mean difference −21.9 ± 66.7, p = 0.502) as well as a significant increase for position 3 (mean difference 81.7 ± 49.2, p = 0.021).
The aim of the current study was to examine the effects of a 6-week training program that uses the FB as compared to the TB in the bench press exercise in a sample of collegiate club powerlifters. The training programs for each group were equal in duration, volume, and loading. Maximum strength, peak force, and peak impulse were tested before and after training intervention. The major findings were that 1RM strength increased for both groups, with no significant differences between the groups. This supports our primary hypothesis. An increase in peak force at all 3 positions for the FB group and for only position 3 for the TB group partially supports our second hypothesis. Our finding of no significant difference between peak impulse at any bench position across the groups does not support our final hypothesis.
The ∼7- and 5-kg increase in strength for the FB and TB groups, respectively, is comparable with a previous linear periodized 6-week strength training program for the bench press exercise (45). Both groups showed improvement in 1RM strength; however, the use of the FB did not further increase performance. Despite the lack of significance between the groups, a few findings for the 1RM data should be emphasized. For example, all subjects in the FB group increased in maximum strength with minimal to no change in body weight after training. A closer examination shows that subjects 1 and 4 had substantial increases of 9 kg. Notably, Subject 1 is an advanced bench presser with a BP/BW of 1.7. Overall, both groups reported a small within-group Cohen d effect size because of a large amount of pretest variability for each group. The authors understand the cautions related to reporting within-group effect size (8). A review by Dankel et al. (8) highlights the widespread misuse of effect size in low sample-size studies and how its misuse affects the interpretation of the findings. A recommendation is to report all the raw data values, such as those seen in Table 4. A supporting recommendation from Weissgerber et al. (44) is to report raw data not only in table form but also in graphical form (Figure 6), which allows readers to evaluate the trends of the study and to make their own interpretations.
A nonsignificant increase in force production of 16, 17.5, and 21.5% occurred at positions 1, 2, and 3, respectively, for the FB group. There are 2 possible explanations for this finding. First, this may have reflected the lifters' improved ability to increase force in the vertical direction. The FB provides a unique feature providing medial-lateral resistance along the horizontal axis of the barbell, which may train the lifter to produce more lateral and vertical force generation (10). Second, the moderate instability from the FB may have forced lifters to maintain tightness throughout the training repetitions, which improves the lifters' ability to prevent their muscles from going lax during the bench press, thus producing greater transfer of force in the vertical direction. This is supported in previous studies that used UL in the bench press, which created unwanted perturbation of the barbell, particularly when lifters perform the concentric phase as quickly as possible (31). The decrease in force production for the TB is more difficult to explain. The TB group reported decreases of 7 and 6% at positions 1 and 2, respectively, with a significant within-group increase of 14% at position 3. The decrease in force production for positions 1 and 2 was unexpected; however, the precipitous drop for Subject 10 (delta z-scores = −2.27, −1.47) contributed to this occurrence.
Similar to the findings of Clark et al. (7), although we graphed the impulse (N·s), the data indicate the lowest level of force at position 1, a progressive increase at position 2, and the largest force production at position 3. Our final hypothesis was not supported because there was no significant difference in peak impulse between the groups at any position. A possible rationale for this finding is that the 1-second time interval used for the peak impulse calculation is too short of an interval to accurately assess the ability to maintain peak tension at each position. Thus, we suggest that a longer time interval, such as 3–5 seconds, should be used to more accurately measure peak impulse or the ability to maintain tension near peak force for a given amount of time. If lifters improve their ability to maintain peak force over a specific interval, subjects could keep tension and stability for heavy intensities (>90% 1RM) and repetitions, approaching muscular failure.
The 3-position pause bench press was chosen because it forced the subject to control the barbell at each theoretical sticking point, and the mounted force plate allowed us to test force production at each point. The primary goal of the training program was to increase bench press performance, which, for powerlifters, is 1 of the 3 primary competition lifts. Furthermore, the bench press exercise is a common focus of research that examines the multiple variables that affect bench press performance, including time under tension (36), tempo (17,35), contraction type (21), range of motion (7,28), surface stability (15,26,33), barbell stability (11,29,31), bar width (13), and grip width (14,34). Despite a large body of research on the multiple ways to improve bench press performance, one consistent challenge is to increase force production through the sticking point. The sticking point, or sticking region, has an ambiguous definition, but a recent work by Kompf and Arandjelovic (24) defined it as the point at which failure occurs when exercise is taken to the point of momentary muscular failure. Previous definitions include the point where the initial deceleration of the barbell velocity occurs during the concentric phase (42).
The sticking point is complex and exists across all 3 powerlifting competition lifts (25). Computer-based models illustrate its complexity, showing that 2 lifters with the same level of bench press strength have sticking points at 2 separate ranges of motion (1). Specific to the bench press, the sticking point can vary across lifters due to multiple factors, such as the lifter's anthropometry (5), training status (12), success of the lift (41), and grip width (14) as well as how the bench is performed, i.e., with or without countermovement (42). Increased knowledge of the biomechanics and physiological mechanisms of the sticking point has resulted in various training techniques to improve sticking point strength. Coaches should implement a variety of training methods to improve a lifter's “weakest link.” Training methods such as accommodating resistance, partial range of motion training, alterations in technique, and target muscle strengthening isolation work are worthy of consideration (25).
There are several limitations to the current study. First, the authors recognize the low statistical power of the design, which is due to the small sample size. We chose to only include subjects who were familiar with the powerlifting training program and who could adhere to the team's training schedule to reduce variability and drop out. We believe that requiring participation in the powerlifting club for 1 year increased the adherence rate to the program and avoided disruptions to team training sessions, which, in turn, reduced our total sample size. Second, the novelty of the FB coupled with what can be considered a short training period may not have allowed the subjects sufficient familiarity with the adaptations of the bar. Most linear periodization programs are 9–12 weeks in duration (16). All subjects in the FB group were familiar with the competition bench press but had never used the FB. A longer training intervention would allow subjects to become more familiar with the articulating handles and to become more adept at using the barbell correctly. A final limitation is the heterogeneity of the pretesting data. The sex differences created a large spread in the variability of pretest scores, which reduced the design sensitivity. Although the authors matched the subjects on pretest 1RM bench to increase sensitivity, a more homogeneous group would likely have reduced the spread of scores.
Future research should include electromyography analysis to better quantify muscle activation during use of the FB or other specialty bars on the commercial market (9). It is likely that the resisted glenohumeral horizontal adduction and internal rotation would stimulate a large recruitment of the pectoralis major muscle, which is the prime mover in the bench press exercise (39).
Unstable load training, particularly the use of specialty bars that provide instability at the barbell itself, is a recent focus in sports science (6,31). The current study supports the use of the FB to increase maximum strength and force production to levels that are comparable with TB training. The moderate level of instability provided by the articulating handles of the FB allows lifters to apply force in the medial-lateral and vertical directions. This, in conjunction with the ability to adequately load the FB in a manner that is comparable with that of a TB, provides an alternative method to increase upper-body strength in the bench press exercise. Training with the FB will train the lifter to apply lateral and medial forces, producing more vertical force during concentric contraction (10). This can be a practical application of the FB in regard to exercise prescription. The increase in muscular strength and force production at all 3 bench positions at the conclusion of the intervention for subjects in the FB group demonstrates that the FB can be used as an assistance exercise for the bench press. Nevertheless, the lack of statistical differences between the FB and TB groups demonstrates that there are no significant advantages to using the FB in place of the TB for the bench press exercise.
1. Arandjelovic O. Optimal effort investment for overcoming the weakest point: New insights from a computational model of neuromuscular adaptation. Eur J Appl Physiol 111: 1715–1723, 2011.
2. Beck TW. The importance of a priori sample size estimation in strength
and conditioning. J Strength
Cond Res 27: 2323–2337, 2013.
3. Behm DB, Muehlbauer T, Kibele A, Granacher U. Effects of strength
training using unstable surfaces on strength
, power and balance performance across the lifespan: A systematic review and meta-analysis. Sports Med 45: 1645–1669, 2015.
4. Bryce AR, Fry AC, Land MT, Giancana N, Spencer R, Scherer E. Comparison of bench press peak force at various intensities between the tsunami barbell and Olympic standard barbell. Int J Exerc Sci 11: 37, 2015.
5. Caruso JF, Taylor ST, Lutz BM, Olson NM, Mason ML, Borgsmiller JA, Riner RD. Anthropometry as a predictor of bench press performance done at different loads. J Strength
Cond Res 26: 2460–2467, 2012.
6. Caterisano A, Hutchison R, Abernethy D, Jakiela JT. Improved functional power over a 5-week period: Comparison of traditional training to tsunami barbell training. Med Sci Sports Exerc 45: 593, 2013.
7. Clark RA, Humphries B, Hohmann E, Bryant AL. The influence of variable range of motion training on neuromuscular performance and control of external loads. J Strength
Cond Res 25: 704–711, 2011.
8. Dankel S, Mouser JG, Mattocks KT, Counts BR, Jessee MB, Buckner SL, Loprinzi PD, Loenneke JP. The widespread misuse of effect sizes. J Sci Med Sport 20: 446–450, 2017.
9. Dorey-Monett Ind. Inc. Articulating Handles. Available at: www.strongtheorysystems.com
. Accessed October 18, 2017.
10. Duffey MJ, Challis JH. Vertical and lateral forces applied to the bar during the bench press of novice lifters. J Strength
Cond Res 25: 2442–2447, 2011.
11. Dunnick DD, Brown LE, Coburn JW, Lynn SK, Barillas SR. Bench press upper-body muscle activation between stable and unstable loads. J Strength
Cond Res 29: 3279–3283, 2015.
12. Elliott BC, Wilson GJ, Kerr GK. A biomechanical analysis of the sticking region in the bench press. Med Sci Sports Exerc 21: 450–462, 1989.
13. Fioranelli D, Lee CM. The influence of bar diameter on neuromuscular strength
and activation: Inferences from an isometric unilateral bench press. J Strength
Cond Res 22: 661–666, 2008.
14. Gomo O, van den Tillaar R. The effects of grip width on sticking region in bench press. J Sports Sci 34: 232–238, 2016.
15. Goodman CA, Pearce AJ, Nicholes CJ, Gatt BM, Fairweather IH. No differences in 1RM strength
and muscle activation during the barbell chest press on stable and unstable surface. J Strength
Cond Res 22: 88–94, 2008.
16. Harries SK, Lubans DR, Callister R. Systemic review and meta-analysis of linear and undulating periodized resistance training programs on muscular strength
. J Strength
Cond Res 29: 1113–1125, 2015.
17. Headley SA, Kelley H, Nindl BC, Thompson BA, Kraemer WJ, Jones MT. Effects of lifting tempo on one repetition maximum and hormonal responses to a bench press protocol. J Strength
Cond Res 25: 406–413, 2011.
18. Hoffman JR, Cooper J, Wendell M, Kang J. Comparison of Olympic vs. traditional power lifting training programs in football players. J Strength
Cond Res 18: 129–135, 2004.
19. International Powerlifting Federation. Technical Rulebook. Anchorage, AK: United States of America Powerlifting, 2015. Available at: www.usapowerlifting.com
. Accessed November 1, 2017.
20. Jakiela JT, Caterisano A, Hutchison RE, Snook T, Rogers G, Moss RF. Comparison of muscle activity between the tsunami barbell and Olympic barbell. Med Sci Sports Exerc 45: 594, 2013.
21. Keogh JWL, Wilson GJ, Weatherby RP. A cross-sectional comparison of different resistance training techniques in the bench press. J Strength
Cond Res 13: 247–258, 1999.
22. King DA, Gabbert TJ, Dryer C, Gerrard DF. Incidence of injuries in the New Zealand national rugby leagues' sevens tournament. J Sci Med Sports 9: 110–118, 2006.
23. Kohler JM, Flanagan SP, Whiting WC. Muscle activation patterns while stable and unstable loads on stable and unstable surfaces. J Strength
Cond Res 24: 313–321, 2010.
24. Kompf J, Arandjelovic O. Understanding and overcoming the sticking point in resistance exercise. Sports Med 46: 751–762, 2016.
25. Kompf J, Arandjelovic O. The sticking point in the bench press, the squat, and the deadlift: Similarities and differences, and their significance for research and practice. Sports Med 47: 631–640, 2017.
26. Koshida S, Urabe Y, Miyashita K, Iwai K, Kagimori A. Muscular outputs during dynamic bench press under stable versus unstable conditions. J Strength
Cond Res 22: 1584–1588, 2008.
27. Lawrence MA, Leib DJ, Ostrowski SJ, Carlson LA. Nonlinear analysis of an unstable bench press bar path and muscle activation. J Strength
Cond Res 31: 1206–1211, 2016.
28. Massey CD, Vincent J, Maneval M, Moore M, Johnson JT. An analysis of full range of motion vs. partial range of motion training in the development of strength
in untrained men. J Strength
Cond Res 18: 518–521, 2004.
29. Nairn CB, Sutherland CA, Drake JDM. Location of instability
during a bench press alters movement patterns and electromyographical activity. J Strength
Cond Res 29: 3162–3170, 2015.
30. Ojasto T, Hakkinen K. Effect of different accentuated eccentric load levels in eccentric-concentric actions on acute neuromuscular, maximal force, and power responses. J Strength
Cond Res 23: 996–1004, 2009.
31. Ostrowski SJ, Carson LA, Lawrence MA. Effect of an unstable load
on primary and stabilizing muscles during the bench press. J Strength
Cond Res 31: 430–434, 2017.
32. Rhea MR. Determining the magnitude of treatment effects in strength
training research through the use of the effect size. J Strength
Cond Res 18: 918–920, 2004.
33. Saeterbakken AH, Andersen V, Behm DG, Krohn-Hansen EK, Smaamo M, Fimland MS. Resistance-training exercises with different stability requirements: Time course of task specificity. Eur J Appl Physiol 116: 2247–2256, 2016.
34. Saeterbakken AH, Mo D, Scott S, Andersen V. The effects of bench press variations in competitive athletes on muscle activity and performance. J Hum Kinet 57: 61–71, 2017.
35. Sakamoto A, Sinclair PJ. Muscle activations under varying lifting speeds and intensities during bench press. Eur J Appl Physiol 112: 1015–1025, 2012.
36. Schoenfeld BJ, Ogborn DL, Krieger JW. Effect of repetition duration during resistance training on muscle hypertrophy: A systematic review and meta-analysis. Sports Med 45: 577–585, 2015.
37. Sheppard JM, Triplett NT. Program design for resistance training. In: Essentials of Strength
Training and Conditioning. Haff GG, Triplett NT, eds. Champaign, IL: Human Kinetics, 2016. pp: 453.
38. Simmons L. Specialty bars
: Powerlifting USA. Camarillo, CA: Powerlifting USA, 2010. Available at: www.powerliftingusa.com
. Accessed June 21, 2017.
39. Stastny P, Golas A, Blazek D, Maszczyk A, Wilk M, Pietraszewski P, Petr M, Uhlir P, Zajac A. A systematic review of surface electromyography analyses of the bench press movement task. PLoS One 12: 1–16, 2017.
40. Swinton PA, Lloyd R, Agouris I, Stewart A. Contemporary training practices in elite British powerlifters: Survey results from an international competition. J Strength
Cond Res 23: 380–384, 2009.
41. van den Tillar R, Ettema G. A comparison of successful and unsuccessful attempts in maximal bench press. Med Sci Sports Exerc 41: 2056–2063, 2009.
42. van den Tillar R, Ettema G. A comparison of muscle activity in concentric and countermovement maximum bench press. J Hum Kinet 38: 63–71, 2013.
43. van den Tillar R, Saeterbakken AH, Ettema G. Is the occurrence of the sticking point region the result of diminishing potentiation in bench press? J Sports Sci 30: 591–599, 2012.
44. Weissgerber WL, Mili NM, Winham SJ, Garovic VD. Beyond bar and line graphs: Time for a new data presentation paradigm. PLoS Biol 13: 1–10, 2015.
45. Zourdos MC, Jo E, Khamoui AV, Lee RS, Park BS, Ormsbee MJ, Panton LB, Contreras RJ, Kim JS. Modified daily undulating periodization model produces greater performance than a traditional configuration in powerlifters. J Strength
Cond Res 30: 784–791, 2016.