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Concept: Barbell

152

Training the bench press exercise on a traditional flat bench does not induce a level of instability as seen in sport movements and activities of daily living. Twenty participants were recruited to test two forms of instability: using one dumbbell rather than two and lifting on the COR bench compared to a flat bench. Electromyography (EMG) amplitudes of the pectoralis major, middle trapezius, external oblique, and internal oblique were recorded and compared. Differences in range of motion (ROM) were evaluated by measuring an angular representation of the shoulder complex. Four separate conditions of unilateral bench press were tested while lifting on a: flat bench with one dumbbell, flat bench with two dumbbells, COR Bench with one dumbbell, and COR Bench with two dumbbells. The results imply that there are no differences in EMG amplitude or ROM between the COR bench and traditional bench. However, greater ROM was found to be utilized in the single dumbbell condition, both in the COR bench and the flat bench.

Concepts: Fundamental physics concepts, Muscle, Electromyography, Bench press, Abdominal external oblique muscle, Pectoralis major muscle, Clavicle, Barbell

27

This study aimed to investigate the effects of combining elastic bands to free weight (EB+FWR) on the acceleration-deceleration and velocity profiles of the bench press in professional rugby players and recreationally-trained subjects. Sixteen male subjects (8 rugby players and 8 recreationally-trained subjects) were randomly assigned to complete 2 experimental conditions in a cross-over fashion: EB+FWR and FWR. In both conditions, subjects performed one bench-press set to volitional exhaustion with a load equivalent to the 85% of one-repetition maximum (1RM). In the EB+FWR condition, the contribution of elastic resistance was approximately the 20% of selected load (85% of 1RM). Results indicate that EB+FWR condition increased significantly the range of concentric movement in which the barbell is accelerated. This increase was significantly higher in rugby players (35%) in comparison with recreationally-trained subjects (13%). Maximal velocity was also increased in EB+FWR (17%), when compared with FWR condition. These results suggest that when combined with variable resistance (i.e. EB), the external resistance seems to be more evenly distributed over the full range of motion, decreasing the need for dramatic deceleration at the end of the concentric phase. The present data also indicate that the kinematic benefits of a EB+FWR approach seems to be more prominent in athletes from modalities in which high level of strength and power are required (i.e. rugby players).

Concepts: Classical mechanics, Acceleration, Velocity, Kinematics, Bench press, Motion, Powerlifting, Barbell

26

Dunnick, DD, Brown, LE, Coburn, JW, Lynn, SK, and Barillas, SR. Bench press upper-body muscle activation between stable and unstable loads. J Strength Cond Res 29(12): 3279-3283, 2015-The bench press is one of the most commonly used upper-body exercises in training and is performed with many different variations, including unstable loads (ULs). Although there is much research on use of an unstable surface, there is little to none on the use of an UL. The purpose of this study was to investigate muscle activation during the bench press while using a stable load (SL) vs. UL. Twenty resistance-trained men (age = 24.1 ± 2 years; ht = 177.5 ± 5.8 cm; mass = 88.7 ± 13.7 kg) completed 2 experimental conditions (SL and UL) at 2 different intensities (60 and 80% one repetition maximum). Unstable load was achieved by hanging 16 kg kettlebells by elastic bands from the end of the bar. All trial lifts were set to a 2-second cadence with a slight pause at the bottom. Subjects had electrodes attached to 5 muscles (pectoralis major, anterior deltoid, medial deltoid, triceps brachii, and latissimus dorsi) and performed 3 isometric bench press trials to normalize electromyographic data. All 5 muscles demonstrated significantly greater activation at 80% compared with 60% load and during concentric compared with eccentric actions. These results suggest that upper body muscle activation is not different in the bench press between UL and SL. Therefore, coaches should use their preference when designing training programs.

Concepts: Biceps brachii muscle, Triceps brachii muscle, Muscle contraction, Trigraph, Bench press, Muscles of the upper limb, Pectoralis major muscle, Barbell

8

The goal of this randomized, double-blind, cross-over study was to assess the acute effects of caffeine ingestion on muscular strength and power, muscular endurance, rate of perceived exertion (RPE), and pain perception (PP) in resistance-trained men. Seventeen volunteers (mean ± SD: age = 26 ± 6 years, stature = 182 ± 9 cm, body mass = 84 ± 9 kg, resistance training experience = 7 ± 3 years) consumed placebo or 6 mg kg(-1) of anhydrous caffeine 1 h before testing. Muscular power was assessed with seated medicine ball throw and vertical jump exercises, muscular strength with one-repetition maximum (1RM) barbell back squat and bench press exercises, and muscular endurance with repetitions of back squat and bench press exercises (load corresponding to 60% of 1RM) to momentary muscular failure. RPE and PP were assessed immediately after the completion of the back squat and bench press exercises. Compared to placebo, caffeine intake enhanced 1RM back squat performance (+2.8%; effect size [ES] = 0.19; p = .016), which was accompanied by a reduced RPE (+7%; ES = 0.53; p = .037), and seated medicine ball throw performance (+4.3%, ES = 0.32; p = .009). Improvements in 1RM bench press were not noted although there were significant (p = .029) decreases in PP related to this exercise when participants ingested caffeine. The results point to an acute benefit of caffeine intake in enhancing lower-body strength, likely due to a decrease in RPE; upper-, but not lower-body power; and no effects on muscular endurance, in resistance-trained men. Individuals competing in events in which strength and power are important performance-related factors may consider taking 6 mg kg(-1) of caffeine pre-training/competition for performance enhancement.

Concepts: Physical exercise, Exercise, Strength training, Weight training, Caffeine, Bench press, Powerlifting, Barbell

6

The purpose of this study was to analyse the validity and reliability of a novel iPhone app (named: PowerLift) for the measurement of mean velocity on the bench-press exercise. Additionally, the accuracy of the estimation of the 1-Repetition maximum (1RM) using the load-velocity relationship was tested. To do this, 10 powerlifters (Mean (SD): age = 26.5 ± 6.5 years; bench press 1RM · kg(-1) = 1.34 ± 0.25) completed an incremental test on the bench-press exercise with 5 different loads (75-100% 1RM), while the mean velocity of the barbell was registered using a linear transducer (LT) and Powerlift. Results showed a very high correlation between the LT and the app (r = 0.94, SEE = 0.028 m · s(-1)) for the measurement of mean velocity. Bland-Altman plots (R(2) = 0.011) and intraclass correlation coefficient (ICC = 0.965) revealed a very high agreement between both devices. A systematic bias by which the app registered slightly higher values than the LT (P < 0.05; mean difference (SD) between instruments = 0.008 ± 0.03 m · s(-1)). Finally, actual and estimated 1RM using the app were highly correlated (r = 0.98, mean difference (SD) = 5.5 ± 9.6 kg, P < 0.05). The app was found to be highly valid and reliable in comparison with a LT. These findings could have valuable practical applications for strength and conditioning coaches who wish to measure barbell velocity in the bench-press exercise.

Concepts: Statistics, Measurement, Psychometrics, Correlation and dependence, Reliability, Covariance and correlation, Bench press, Barbell

6

The deadlift exercise is commonly performed to develop strength and power, and to train the lower body and erector spinae muscle groups. However, little is known about the acute training effects of a hexagonal barbell vs. a straight barbell when performing deadlifts. Therefore, the purpose of this study was to examine the hexagonal barbell in comparison to the straight barbell by analyzing electromyography (EMG) from the vastus lateralis, biceps femoris, and erector spinae, as well as peak force, peak power, and peak velocity using a force plate. Twenty men, with deadlifting experience volunteered to participate in the study. All participants completed a one-repetition maximum (1RM) test with each barbell on two separate occasions. Three repetitions at 65% and 85% 1RM were performed with each barbell on a third visit. The results revealed there was no significant difference for 1RM values between the straight and hexagonal barbells (mean ± SD in kg = 181.4 ± 27.3 vs. 181.1 ± 27.6, respectively) (p > 0.05). Significantly greater normalized EMG values were found from the vastus lateralis for both the concentric (1.199 ± 0.22) and eccentric (0.879 ± 0.31) phases of the hexagonal barbell compared to the straight barbell deadlift (0.968 ± 0.22 and 0.559 ± 1.26), while the straight barbell deadlift led to significantly greater EMG values from the bicep femoris during the concentric phase (0.835 ± 0.19) and the erector spinae (0.753 ± 0.28) during the eccentric phase compared to the corresponding values for the hexagonal barbell deadlift (0.723 ± 0.20 and 0.614 ± 0.21) (p ≤ 0.05). In addition, the hexagonal barbell deadlift demonstrated significantly greater peak force (2,553.20 ± 371.52 N), peak power (1,871.15 ± 451.61 W), and peak velocity (0.805 ± 0.165) compared to the straight barbell deadlift values (2,509.90 ± 364.95 N, 1,639.70 ± 361.94 W, and 0.725 ± 0.138 m/s) (p ≤ 0.05). These results suggest that the barbells led to different patterns of muscle activation, and that the hexagonal barbell maybe more effective at developing maximal force, power, and velocity.

Concepts: Statistical significance, Muscle, Biceps brachii muscle, Electromyography, Weight training, Vastus lateralis muscle, Deadlift, Barbell

4

Manocchia, P, Spierer, DK, Lufkin, AKS, Minichiello, J, and Castro, J. Transference of kettlebell training to strength, power, and endurance. J Strength Cond Res 27(2): 477-484, 2013-Kettlebells are a popular implement in many strength and conditioning programs, and their benefits are touted in popular literature, books, and videos. However, clinical data on their efficacy are limited. The purpose of this study was to examine whether kettlebell training transfers strength and power to weightlifting and powerlifting exercises and improves muscular endurance. Thirty-seven subjects were assigned to an experimental (EXP, n = 23; mean age = 40.9 ± 12.9 years) or a control group (CON; n = 14; mean age = 39.6 ± 15.8 years), range 18-72 years. The participants were required to perform assessments including a barbell clean and jerk, barbell bench press, maximal vertical jump, and 45° back extensions to volitional fatigue before and after a 10-week kettlebell training program. Training was structured in a group setting for 2 d·wk for 10 weeks. A repeated measures analysis of variance was conducted to determine group × time interactions and main effects. Post hoc pairwise comparisons were conducted when appropriate. Bench press revealed a time × group interaction and a main effect (p < 0.05). Clean and jerk and back extension demonstrated a trend toward a time × group interaction, but it did not reach significance (p = 0.053). However, clean and jerk did reveal a main effect for time (p < 0.05). No significant findings were reported for maximal vertical jump. The results demonstrate a transfer of power and strength in response to 10 weeks of training with kettlebells. Traditional training methods may not be convenient or accessible for strength and conditioning specialists, athletes, coaches, and recreational exercisers. The current data suggest that kettlebells may be an effective alternative tool to improve performance in weightlifting and powerlifting.

Concepts: Exercise, Analysis of variance, Bench press, Barbell, Weightlifting, Olympic weightlifting, Weight training equipment, Kettlebell

3

This study compared the muscular activation of the pectoralis major, anterior deltoid and triceps brachii during a free-weight barbell bench press performed at 0°, 30°, 45° and -15° bench angles. Fourteen healthy resistance trained males (age 21.4 ± 0.4 years) participated in this study. One set of six repetitions for each bench press conditions at 65% one repetition maximum were performed. Surface electromyography (sEMG) was utilised to examine the muscular activation of the selected muscles during the eccentric and concentric phases. In addition, each phase was subdivided into 25% contraction durations, resulting in four separate time points for comparison between bench conditions. The sEMG of upper pectoralis displayed no difference during any of the bench conditions when examining the complete concentric contraction, however differences during 26-50% contraction duration were found for both the 30° [122.5 ± 10.1% maximal voluntary isometric contraction (MVIC)] and 45° (124 ± 9.1% MVIC) bench condition, resulting in greater sEMG compared to horizontal (98.2 ± 5.4% MVIC) and -15 (96.1 ± 5.5% MVIC). The sEMG of lower pectoralis was greater during -15° (100.4 ± 5.7% MVIC), 30° (86.6 ± 4.8% MVIC) and horizontal (100.1 ± 5.2% MVIC) bench conditions compared to the 45° (71.9 ± 4.5% MVIC) for the whole concentric contraction. The results of this study support the use of a horizontal bench to achieve muscular activation of both the upper and lower heads of the pectoralis. However, a bench incline angle of 30° or 45° resulted in greater muscular activation during certain time points, suggesting that it is important to consider how muscular activation is affected at various time points when selecting bench press exercises.

Concepts: Muscle, Triceps brachii muscle, Electromyography, Muscle contraction, Bench press, Pectoralis major muscle, Clavicle, Barbell

2

Those training for strength and power commonly use different bars and different lifts. The hexagonal barbell (HBar) and Olympic barbell (OBar) are frequently used training implements, and the mid-thigh pull and deadlift are two popular exercises. Therefore, the purpose of this study was to compare force between an HBar and OBar for a mid-thigh pull (MTP), deadlift (DL) and countermovement jump (CMJ). Twenty resistance trained men (age = 24.05 ± 2.09 yrs, ht = 178.07 ± 7.05 cm, mass = 91.42 ± 14.44 kg) volunteered to participate and performed MTP and DL utilizing both bars, and a CMJ. Joint angles were recorded for all pulls and the bottom position of the CMJ. Peak ground reaction force (PGRF) was greater in the MTP (3186.88±543.53N) than DL (2501.15±404.04N) but not different between bars. MTP joint angles were more extended than DL, and the strongest correlations between isometric and dynamic performance were seen between DL PGRF and CMJ impulse (OBar r=0.85; HBar r=0.84). These findings are likely due to the different anatomical characteristics between the MTP and DL as well as the similarity in joint angles between the DL and CMJ. Therefore, the deadlift may be an optimal choice for athletes in jump dependent sports, regardless of bar.

Concepts: Mass, Force, Weight training, Classical mechanics, Reaction, Ground reaction force, Newton's laws of motion, Barbell

2

Senna, GW, Willardson, JM, Scudese, E, Simão, R, Queiroz, C, Avelar, R, and Dantas, EHM. Effect of different interset rest intervals on performance of single and multijoint exercises with near-maximal loads. J Strength Cond Res 30(3): 710-716, 2016-The aim of this study was to investigate the acute effects of different interset rest intervals on performance of single- and multijoint exercises with near-maximal loads. Fifteen trained men (26.40 ± 4.94 years, 79.00 ± 7.10 kg, 176.6 ± 6.06 cm, 11.80 ± 2.47% body fat, and bench press relative strength: 1.26 ± 0.19 kg·kg of body mass) performed eight sessions (2 exercises × 4 interset rest intervals); each consisting of 5 sets with a 3RM load. The exercises tested were the machine chest fly (MCF) for the single-joint exercise and the barbell bench press (BP) for the multi-joint exercise with 1, 2, 3, and 5 minutes of rest between sets. The results indicated that for the MCF, significantly higher total number of repetitions were completed for the 2- (12.60 ± 2.35 reps; p = 0.027), 3- (13.66 ± 1.84 reps; p = 0.001), and 5-minute (12.93 ± 2.25 reps; p = 0.001) vs. the 1-minute (10.33 ± 2.60 reps) protocol. For the BP, a significantly higher total number of repetitions were completed for 3- (11.66 ± 2.79 reps; p = 0.002) and 5-minute (12.93 ± 2.25 reps; p = 0.001) vs. the 1-minute protocol (7.60 ± 3.52 reps). In addition, subjects completed significantly higher total number of repetitions for the 5-minute (12.93 ± 2.25 reps; p = 0.016) vs. 2-minute (9.53 ± 3.11 reps) protocol. Both exercises presented similar and progressive reductions in repetition performance for all rest protocols along the 5 sets, starting as soon as the second set for the shorter 1-minute rest protocol. In conclusion, to maintain the best consistency in repetition performance, rest intervals of 2 minutes between sets are sufficient for the MCF and 3-5 minutes for the BP. Thus, it appears that longer acute recovery time is needed for a multijoint (core) exercise such as the BP vs. a single-joint (assistance) exercise such as the MCF.

Concepts: Obesity, Physical exercise, Exercise, Strength training, Weight training, Physical fitness, Bench press, Barbell