Abstract

Purpose: This study aimed to assess the effects of barbell (BBP) or dumbbell (DBP) bench press on one repetition maximum (1RM), increases in throwing performance, and transfer effect from one exercise to the other.

Methods: Thirty resistance-trained men (age, 18.1 ± 0.5 years; weight, 97.4 ± 11.3 kg; height, 183.7 ± 11.3 cm) were randomly assigned to either a BBP [G1 (n = 16)] or DBP [G2 (n = 14)] and completed two weekly training sessions at a relative percentage of the respective 1RM for 12 weeks. Study outcomes included strength levels measured using 1RM in BBP and DBP, and power measured by the seated medicine ball throwing test.

Results: A significant main effect of time for 1RM BBP (F (1,28) = 212.952, p < 0.001, $\omega_{}^{2}$ = 0.387), 1RM DBP (F (1,28) = 88.325, p < 0.001, $\omega_{}^{2}$= 0.336), and seated medicine ball throw (F (1,28) = 66.579, p = 0.001, $\omega_{}^{2}$ = 0.241) was found. No significant interactions were observed between group and time for any of the dependent variables.

Conclusions: BBP and DBP exercises may be equally efficacious in improving upper-body strength and power in resistance-trained men.

🏷️Keywords: muscle strength, transfer effect, free weights, upper extremity

Introduction

The barbell bench press (BBP) is a widely used exercise in resistance training programs to develop upper-body musculature. Because of its popularity and effectiveness, extensive research has been conducted to investigate its mechanical and physiological responses (Sakamoto & Sinclair, 2011; Lacerda et al., 2019) and the effectiveness of different resistance training modalities for improving physical conditioning in both novices and athletes (McCurdy et al., 2009; Smoak, 2022). The exercise primarily targets the pectoralis major, triceps brachii, and anterior deltoid muscles (Stastny et al., 2017) and can be performed using a barbell or a dumbbell.

One key distinction between the BBP and dumbbell bench press (DBP) is their differing levels of stability. DBP requires greater muscular stabilization and control because of the increased freedom of movement in multiple planes, whereas BBP requires less balance of the external load. The instability inherent in DBP may prevent the upper body from effectively engaging the muscles typically activated during BBP, leading to altered muscle forces during movements (Elliot, Wilsom, & Kerr, 1989). A previous study showed that BBP allowed individuals to lift heavier loads than DBP (Saeterbakken et al., 2011; Farias et al.,2017) . For example, Saeterbakken et al. (2011) reported that the BBP load was 17% greater than the one used in the one repetition maximum (1RM) test for DBP.

However, research investigating the simultaneous application of both exercises to improve maximal strength and power performance is limited. Currently, comparative data on these exercises are scarce and primarily consist of electromyographic analyses or biomechanical comparison studies (Farias et al., 2017; Heinecke et al., 2020; Welsch et al., 2005). Despite the significance of understanding the kinetic and muscle activity during an exercise, direct comparison of long-term measurements such as strength and power and the transfer of gains between the BBP and DBP is equally important. Surprisingly, to our knowledge, no studies have investigated these effects.

Therefore, given the limited research, this study aimed to evaluate (a) the effect of a 12-week training intervention program using both BBP and DBP on strength, (b) the influence of BBP and DBP on enhanced throwing performance, and (c) the transferability of the training effect from BBP to DBP and vice versa.

Material and methods

Study design

This study utilized a randomized, pre- and post-test repeated-measures design. The participants were randomly divided into two parallel groups using simple randomization procedures (computer-based random numbers in a 1:1 ratio). G1 (n = 16) included only BBP as an upper-body strength exercise, while G2 (n = 14) included only DBP as an upper-body resistance exercise. The study was conducted for 14 weeks, consisting of a pretest in week 1, a training intervention program from weeks 2 to 13, and a post-test in week 14. The training intervention program consisted of two weekly training sessions for 12 weeks, with participants performing the same training volume, frequency, range of motion, and rest interval between sets. All training sessions were completed under the direct supervision of a certified strength and conditioning specialist.

Baseline testing was conducted on two separate days, each separated by 48 h. Day 1 consisted of anthropometry measurements, followed by a 1RM test. The strength tests for both BP variations were conducted on days 1 and 2, with the testing order counterbalanced to avoid an order effect. The power test was performed on day 2, after the strength test, with a mandatory 15-min rest period. After the intervention period, all baseline tests were repeated. Figure 1 illustrates the steps in the process.

Participants

Forty healthy men participated voluntarily in this study. After accounting for dropouts, 30 participants (age, 22.7 ± 4.1 years; weight, 71.2 ± 7.7 kg; height, 172.4 ± 5 cm) completed the study (Figure 2). The inclusion criteria required participants to be 20–30 years old, have at least 3 years of consistent resistance training experience, be free from current or previous injuries that could be aggravated by upper-body exercises, and have refrained from taking drugs or supplements for 6 months before the study. In addition, the participants must be technically proficient in both BBP and DBP techniques. They were instructed not to train for 72 h before the testing session.

Before the study began, each participant received information about the study’s goals, requirements, benefits, and inherent risks and provided written informed consent. The study adhered to all relevant national requirements and institutional guidelines, followed the principles set in the Declaration of Helsinki, and complied with the current ethical standards in sports and exercise science research.

Procedures

1RM assessment

The assessment of 1RM for both BP variations was performed folloing the guidelines suggested in a previous report (Mayhew, et al. 1992). Briefly, after a 10-min warm-up on a static bicycle, participants performed three warm-up sets: (1) five repetitions at 50% of the estimated 1RM (based on a previous training history), (2) three repetitions with an additional 2.5–5 kg, and (3) one repetition with additional 2.5–5 kg. This procedure was repeated with a series of single attempts until the participants were unable to lift a heavier weight. A 3-min rest interval between each trial was allowed. In the BBP, participants grasped the bar at a position slightly greater than the biacromial width, whereas the arm position was individually selected using the dumbbells. Participants lowered the bar or dumbbell smoothly and precisely to the lower portion of the pectorals and then rapidly extended the arms to full extension. Two spotters assisted the participants during the unracking and reracking of the barbell and helped stabilize the dumbbell until participants had fully extended arms in each set.

Seated medicine ball throw assessment

Upper-body explosiveness was determined by throwing a 3-kg and 22-cm diameter rubber medicine ball (MB; Soomloom, Japan). The MB was slightly covered with magnesium carbonate powder to ensure a reliable and stronger grip and prevent slipping of the ball from the hands. This also left a mark on the floor where the ball landed and ensured precise measurement of the throwing distance. From a sitting position on a bench with support for the back, the participants were instructed to keep their upper back firmly pressed against the backstop, staying in contact throughout the full throw to avoid any observable trunk flexion movement, grasped the MB against their chest with both hands, and on the given audible sign pushed the ball from the center of the chest with maximal effort as far forward as possible. The participants performed three trial throws, separated by approximately 2 min of recovery between each trial. The distance score was measured from the starting line to the midpoint of the mark left by the MB on the floor. The distance for each test was recorded to the nearest 1 cm, and the average distance score was utilized for statistical analysis. The test–retest reliability coefficient was r ≥0.95

Intervention program

The intervention program lasted 12 weeks and consisted of two training sessions per week. To ensure sufficient recovery between sessions, the training was performed on Tuesdays and Saturdays. Each session included only one exercise, the BBP or the DBP. Groups followed the same prescribed training loading pattern for 12 weeks and were divided into four periods of 3 weeks each, with progressively increasing intensity and decreasing training volume proportionately at each phase. In the first (weeks 2–4), second (weeks 5–7) and third (weeks 8–10) phases, the participants performed 3–5 sets of 8 repetitions at 72%–77% of 1RM, 5 repetitions at 80%–85% of 1RM and 3 repetitions at 87%–92% of 1RM respectively. In the final phase (weeks 11–13), the participants performed a descending load scheme of distributing the training load. In this approach, the load increased progressively to higher intensity (85%–98% of 1RM), whereas the number of repetitions decreased in each set. Phases 1 and 2 utilized 2–3 min of recovery between sets, whereas phases 3 and 4 used 3–5 min inter-set rest (Table 1).

Table 1. Training program.

Data processing and analysis

JASP version 0.16.3 (JASP Team, 2022) was used for data analysis. A mixed-factor analysis of variance was used to determine the effects of both BBP and DBP on muscular strength and power. Before the analysis, the normal distribution of the data was confirmed for all factor combinations using the Shapiro–Wilk test, whereas Levene’s test was used to test for homogeneity of variances. The level of statistical significance was accepted at p <.05.

Results

The results on the analyses of strength and power indicated a significant main effect of time for 1RM BBP (F (1,28) = 212.952, p < 0.001, $\omega_{}^{2}$ = 0.387), 1RM DBP (F (1,28) = 88.325, p < 0.001, $\omega_{}^{2}$= 0.336), and seated medicine ball throw (SMBT) (F (1,28) = 66.579, p = 0.001, $\omega_{}^{2}$ = 0.241). However, no significant main effect for group was observed for 1RM BBP (F (1,28) = 0.476, p = 0.496, $\omega_{}^{2}$ = 0.000), 1RM DBP (F (1,28) = 0.795, p = 0.380, $\omega_{}^{2}$ = 0.000), or SMBT (F (1,28) = 1.431, p = 0.242, $\omega_{}^{2}$ = 0.007) (Table 2).

Table 2. Pre- and post-testing values (mean ± SD).

Discussion

This study presents that different upper-body strength training programs, in which participants performed either BBP or DBP, displayed similar increases in strength and power.

G1 and G2 showed significant improvements in muscle strength, with 12% and 10% increases in BBP 1RM and 13.7% and 14.3% improvements in DBP 1RM, respectively. These findings support the results of previous studies indicating that increases in maximum strength are highly specific to the exercise being performed (Behm et al., 2002; Speirs et al., 2016). Furthermore, the results show a positive cross-training effect between BBP and DBP, although transfer from BBP to DBP was greater than from DBP to BBP. Previous studies have reported varying transfer effects between exercises (Wilson & Murphy, 1996; Nigro & Bartolomei, 2020), indicating the importance of exercise selection in designing training programs.

A previous study indicated that the stability requirements of BBP and DBP are different, leading to varying levels of muscle activation for agonist, synergist, and antagonist muscles (Saeterbakken., 2011). This may help explain the finding of the present study that the increase in 1RM for G2 may be due to both strength and motor strategy improvements, with only strength gains being transferable to BBP because it requires less stabilizing motor strategy than DBP. On the contrary, the 1RM increase in G1 may be solely attributed to strength gain, which can be fully transferred to DBP.

These differences in the force output under different dynamic conditions were also reported by Behm et al. (2002) , who found that less stable movements produce lower force levels than more stable movements. Consequently, part of the muscular activity is used to stabilize undesirable movements [16], reducing the effectiveness of motor strategy. Ostrowski et al. (2017) compared the effects of stable and unstable loads on primary and stabilizing muscles during BP. In less stable conditions, the level of synergist and antagonist muscle activation increased, whereas the activation of agonist muscles remained similar to the more stable condition. This indicates that the increased antagonist muscular co-activation is produced to enhance joint stability and reduce the external force level that can be generated for a given level of agonist muscle force. Therefore, when exercises are less stable, training loads are often lighter [18].

Improvements in coordination may play a significant role in strength gains during less stable exercises. A study showed that training with an unstable exercise leads to a rapid reduction in antagonist activation and an increase in synergist activation [19].

In addition, both variations in BP exercise resulted in a significant increase in the throwing distance (10.2% and 10.6% for G1 and G2, respectively) from pre- to post-test, although no significant interactions were found between groups noted for the SMBT test.

The similarity between movements in the trained exercises and the throwing test appears to be the reason for the observed improvements. Abernethy and Jürimäe (Abernethy & Jürimäe, 1996) suggested that training effects are best evaluated when the test movement pattern is similar to the trained exercise. In both BBP and DBP, participants executed shoulder lateral adduction and elbow extension while pushing against resistance. The prescribed strength stimulus and subsequent improvements in upper-body strength for each group enhanced the force generation capacity required for a throw, mainly through increased motor unit recruitment (Terzis et al., 2008). This confirms the relationship between maximum strength and power suggested by several authors (Chiu, 2007; Bompa & Buzzichelli, 2015).  Indeed, Stone et al. (2003) demonstrated a strong correlation between muscle strength and throwing performance.

However, more significant changes could be achieved with specific power training to fully exploit the increase in muscle strength (Bompa & Buzzichelli, 2015). Coordination improvements in maximum strength movements and high-velocity strength movements are different (Coburn et al., 2006); thus, simply increasing the maximum strength does not necessarily improve power without specific training (Bobbert & van Soest, 1994).

Incorporating both BBP and DBP in a training program may improve strength levels by enhancing inter- and intramuscular coordination and targeting specific adaptations. A combination of horizontal pressing movements with different stability levels may be advantageous, with BBP improving agonist muscle activation and DBP increasing synergistic muscle activation while decreasing antagonist muscle co-activation.

Conclusions

The results of this study suggest that incorporating both BBP and DBP into a 12-week training program can effectively enhance upper-body strength and power in resistance-trained men. Thus, if the training program aims to increase muscle strength and power, then either training modality can be used effectively to achieve this outcome. However, these findings may not necessarily apply to longer training programs or less-experienced individuals. Furthermore, the maximal force capacity developed in resistance training—regardless of BBP or DBP training parameters—can be transferred to throwing performance where the common requirement is the ability to produce initial high levels of force with greater reliance on concentric strength. However, regarding throwing performance, coaches should select exercises that address the underlying neuromuscular requirements of the task rather than focus on exercises that appear similar to the target performance. In this regard, increasing eccentric strength is a necessary strategy.