Machine Bench Press Research Articles

Estimating Repetitions in Reserve During the Bench Press Exercise: Should We Consider Sex and the Exercise Equipment?

Estimating repetitions in reserve (RIR) has been established as a valid and practical method for monitoring set configuration concerning proximity to failure in resistance training. However, factors such as sex and exercise equipment could interfere with the estimation process. Therefore, this study aimed to determine the influence of sex (female vs male) and exercise equipment (free-weight vs Smith machine) on the RIR estimation at different relative loads during the bench press exercise. Men would be more accurate than women in the RIR estimation, and participants would better perceive their actual effort at the Smith machine compared with the free-weight bench press exercise. Repeated measures design. Level 3. In a counterbalanced order, recreationally trained participants (12 female, 14 male) performed 2 identical sessions with the free-weight bench press exercise in 1 week and 2 identical sessions with the Smith machine bench press exercise in another week (first session for familiarization and second session for validity analysis). In each session, participants performed single sets of repetitions to failure against 3 relative loads (65%, 75%, and 85% of the 1-repetition maximum [1RM]). Results revealed a significant interaction between RIR and sex at 65% 1RM (P < 0.01; women: -1.2 [-1.7 to -0.6] repetitions; men: -0.1 [-0.6 to 0.3] repetitions), and between RIR and exercise equipment at 65% 1RM (P < 0.01; free-weight: -1.1 [-1.5 to -0.6] repetitions; Smith machine: -0.2 [-0.6 to 0.2] repetitions), but not at 75% and 85% 1RM. RIR estimation is a valid method for monitoring set configuration. However, this method tends to underestimate RIR at 65%1RM with female athletes and in the free-weight exercise for both sexes. Strength and conditioning coaches should help their athletes understand effort awareness in the aforementioned context.

Effects of Eccentric Phase Velocity on Bench Press Concentric Bar Velocity in the Young and Elderly.

This study aimed to investigate the impact of bar velocity during the eccentric phase on subsequent concentric performance in the young and elderly. Twelve elderly women (65.2+4.2 years) and 16 young women (23.1+2.1 years) were randomly assigned to four experimental conditions that combined high-velocity eccentric actions (HVECC; maximum velocity) and moderate-velocity eccentric actions (MVECC; 2.0 s), using 30% and 60% of their 1-repetition maximum (1RM) on the Smith machine bench press. Measurements of mean propulsive velocity (MPV), peak velocity (PV), and mean power (MP) were recorded. Two-way ANOVA with repeated measures was applied for each variable, when needed, the Bonferroni post hoc was used. Statistical significance was set at p<0.05, and effect size (ES) was established by Cohen's d z. The results demonstrated that elderly women showed improved performance in MPV (+10.0%; ES=- 0.58; p=0.009) and MP (+11.7%; ES=- 0.14; p=0.045) when utilizing HVECC at 30% 1RM only. Moreover, young women exhibited superior performance for both 30% and 60% 1RM when using HVECC for all variables analyzed (p<0.05). The HVECC appears to have an impact on the subsequent performance of the concentric phase, particularly when lighter loads (30% 1RM) are utilized, regardless of the age group.

Simultaneous Upper- and Lower-Limb Postactivation Performance Enhancement After Clean and Jerk.

Studies on postactivation performance enhancement (PAPE) have used different exercises as a conditioning activity to investigate potentiation, but exclusively in upper limbs (UL) or lower (LL) limbs, or contralateral potentiation. A single exercise capable of inducing PAPE in both UL and LL is currently unknown. The present study explored the effect of the clean and jerk (C&J) as a conditioning activity for simultaneously producing PAPE interlimbs at the fourth, seventh, and 12th minutes postintervention. Twelve male weightlifters with 1-repetition maximum (1RM) in the C&J equivalent to ≥1.15 × body mass were randomly submitted to 2 experimental conditions (C&J and control [CON]). The C&J condition consisted of general warm-up (running on a treadmill and self-selected preparatory exercises) and 4 sets of 3 repetitions of C&J with 2minutes between them (30%1RM, 50%1RM, 65%1RM, and 80%1RM) followed by a countermovement jump and a bench-press throw on a Smith machine after 4, 7, and 12minutes, to measure the magnitude of PAPE in UL and LL. No previous exercise preceded countermovement-jump and bench-press-throw tests in the CON besides general warm-up. The main finding was that, regardless of time, the C&J resulted in greater height on countermovement jump and Smith machine bench-press throw when compared with the CON, presenting a similar effect size between UL and LL (34.6 [3.9] vs 33.4 [4.1]cm [+3.66%]; P = .038; effect size = 0.30 and 30.3 [4.7] vs 29.0 [5.1]cm [+4.44%]; P = .039; effect size = 0.26), respectively. Thus, C&J can be useful to produce PAPE simultaneously among members.

Optimal Minimum Velocity Threshold to Estimate the 1-Repetition Maximum: The Case of the Smith Machine Bench Press Exercise.

To compare the accuracy in the estimation of the Smith machine bench press 1-repetition maximum (1RM) when using a novel minimum velocity threshold (MVT) called optimal MVT (MVT that minimizes the differences between the actual and predicted 1RM in a preliminary session) with respect to using the 2 standard MVTs (general and individual MVTs). A total of 126 young men (Smith machine bench press 1RM = 80.7 [13.6]kg) completed 2 identical sessions consisting of an incremental loading test until reaching the 1RM load. Four individual load-velocity relationships were modeled in each session considering all loading conditions until reaching the load that showed the closest mean velocity to 0.60, 0.50, 0.40, and 0.30m·s-1. The first testing session was used to determine the preindividual MVT and 4 optimal MVTs (1 for each final test velocity), while the second testing session was used to estimate the 1RM using 4 types of MVT (general MVT, preindividual MVT, actual-individual MVT, and optimal MVT). The absolute errors in the prediction of the 1RM were significantly lower for the optimal MVT (2.94 [2.40]kg) compared to the general MVT (3.66 [2.99]kg), preindividual MVT (3.80 [3.15]kg), and actual-individual MVT (4.02 [3.21]kg). The optimal MVT (intraclass correlation coefficient [ICC] ranged from .56 to .62) was always more reliable than the individual MVT (ICC = .34). The optimal MVT provides more accurate estimates of the Smith machine bench press 1RM than the standard MVTs previously used in scientific research (general and individual MVTs).

The placement of linear transducers affects the magnitude but not the intra-session reliability of kinematic variables during the bench press exercise

BACKGROUND: While linear transducers are the most accurate velocity monitoring devices, the horizontal motion of the barbell seems to affect its measurement error. OBJECTIVE: To explore the effect of cable inclination of the GymAware and T-Force linear transducers on the intra-session reliability and magnitude of kinematic variables during the Smith machine bench press exercise. METHODS: Twenty-eight resistance-trained males performed 2 blocks of 12 repetitions (4 repetitions at 40-60-80%1RM). In half of the repetitions with each load the two measuring systems were either vertically aligned with the barbell or positioned 15-cm away from the vertical projection of the barbell. RESULTS: Displacement and mean velocity variables were recorded with a high and comparable intra-session reliability regardless of the cable position and measuring system (CV=𝑟𝑎𝑛𝑔𝑒 1.79–8.38%; ICC=𝑟𝑎𝑛𝑔𝑒 0.69–0.98). The inclined cable position provided a lower displacement and mean velocity than the vertical cable position and the differences were comparable using both the GymAware (⩽ 1.52 cm; ⩽ 0.05 m⋅s-1) and T-Force (⩽ 1.53 cm; ⩽ 0.04 m⋅s-1). CONCLUSIONS: These results indicate that repeatable findings of kinematic variables can be obtained regardless of the cable position, but for comparative purposes, the cable position should remain constant from the start to the end of the lifts.

Estimation of 1-Repetition Maximum Using a Hydraulic Bench Press Machine Based on User's Lifting Speed and Load Weight.

1-repetition maximum (1RM), a representative index for an individual’s weightlifting capacity, provides an organized workout guide, but to measure 1RM needs several repetitive exercises up to one’s limit and has a risk of injury, thus, not adequate for beginners, elders, or disabled people. This study suggests a simpler and safer 1RM measurement method using a hydraulic fitness machine. We asked twenty-five female subjects with less than a month of experience in weight training to repeat chest exercises using a conventional plate-loaded bench press machine and a hydraulic bench press machine and measured 1RMs. Repeated-measures ANOVA and paired t-test reported the difference between the plate and hydraulic 1RMs insignificant (p-value = 0.082) and confirmed the generality of 1RM across the different types of fitness machines. We then derived several 1RM equations in terms of load weight and lifting speed during non-1RM exercise and reduced it to a first-order polynomial expression with adjusted R-square of 0.8849. Goodness-of-fit test and comparison with 1RM equations from reference studies () verified our formula valid. We finally simplified the 1RM measurement process up to a maximum of three repetitions.

The ADR Encoder is a reliable and valid device to measure barbell mean velocity during the Smith machine bench press exercise

Velocity-based training is a contemporary resistance training method, which uses lifting velocity to prescribe and assess the effects of training. However, the high cost of velocity monitoring devices can limit their use among strength and conditioning professionals. Therefore, this study aimed to examine the reliability and concurrent validity of an affordable linear position transducer (ADR Encoder) for measuring barbell velocity during the Smith machine bench press exercise. Twenty-eight resistance-trained males performed two blocks of six repetitions in a single session. Each block consisted of two repetitions at 40%, 60%, and 80% of their estimated one-repetition maximum. The mean velocity of the lifting phase was simultaneously recorded with the ADR Encoder and a gold-standard linear velocity transducer (T-Force® System). Both devices demonstrated high reliability for measuring mean velocity (ADR Encoder: CVrange = 2.80%–6.40% and ICCrange = 0.78–0.82; T-Force® System: CVrange = 3.27%–6.62% and ICCrange = 0.77–0.81). The ADR Encoder provided mean velocity at 40%1RM with a higher reliability than the T-Force® System (CVratio = 1.17), but the reliability did not differ between devices at higher loads (60%1RM–80%1RM) (CVratio ≤ 1.08). No fixed or proportional bias was observed for the different loads using least-products regression analysis, while the Bland–Altman plots revealed low systematic bias (0.01 m·s−1) and random errors (0.03 m·s−1). However, heteroscedasticity of the errors was observed between both devices ( R2 = 0.103). The high reliability and validity place the ADR Encoder as a low-cost device for accurately measuring mean velocity during the Smith machine bench press exercise.

Number of Repetitions Performed Before and After Reaching Velocity Loss Thresholds: First Repetition Versus Fastest Repetition-Mean Velocity Versus Peak Velocity.

To explore the effect of several methodological factors on the number of repetitions performed before and after reaching certain velocity loss thresholds (VLTs). Fifteen resistance-trained men (bench press 1-repetition maximum = 1.25 [0.16]kg·kg-1) performed with maximum intent a total of 182 sets (77 short sets [≤12 repetitions] and 105 long sets [>12 repetitions]) leading to failure during the Smith machine bench press exercise. Fifteen percent, 30%, and 45% VLTs were calculated, considering 2 reference repetitions (first and fastest repetitions) and 2 velocity variables (mean velocity [MV] and peak velocity [PV]). The number of repetitions performed before reaching all VLTs were affected by the reference repetition and velocity variable (P ≤ .001). The fastest MV and PV during the short sets (75.3%) and PV during the long sets (72.4%) were predominantly observed during the first repetition, while the fastest MV during long sets was almost equally distributed between the first (37.1%) and second repetition (40.0%). Failure occurred before reaching the VLTs more frequently using PV (4, 8, and 33 occasions for 15%, 30%, and 45% VLTs, respectively) than MV (only 1 occasion for the 45% VLT). The participants rarely produced a velocity output above a VLT once this threshold was exceeded for the first time (≈10% and 30% of occasions during the short and long sets, respectively). The reference repetition and velocity variable are important factors to consider when implementing VLTs during resistance training. The fastest repetition (instead of the first repetition) and MV (instead of PV) are recommended.

Use of Machine-Learning and Load-Velocity Profiling to Estimate 1-Repetition Maximums for Two Variations of the Bench-Press Exercise.

The purpose of the current study was to compare the ability of five different methods to estimate eccentric–concentric and concentric-only bench-press 1RM from load–velocity profile data. Smith machine bench-press tests were performed in an eccentric–concentric (n = 192) and a concentric-only manner (n = 176) while mean concentric velocity was registered using a linear position transducer. Load–velocity profiles were derived from incremental submaximal load (40–80% 1RM) tests. Five different methods were used to calculate 1RM using the slope, intercept, and velocity at 1RM (minimum velocity threshold—MVT) from the load–velocity profiles: calculation with individual MVT, calculation with group average MVT, multilinear regression without MVT, regularized regression without MVT, and an artificial neural network without MVT. Mean average errors for all methods ranged from 2.7 to 3.3 kg. Calculations with individual or group MVT resulted in significant overprediction of eccentric–concentric 1RM (individual MVT: difference = 0.76 kg, p = 0.020, d = 0.17; group MVT: difference = 0.72 kg, p = 0.023, d = 0.17). The multilinear and regularized regression both resulted in the lowest errors and highest correlations. The results demonstrated that bench-press 1RM can be accurately estimated from load–velocity data derived from submaximal loads and without MVT. In addition, results showed that multilinear regression can be used to estimate bench-press 1RM. Collectively, the findings and resulting equations should be helpful for strength and conditioning coaches as they would help estimating 1RM without MVT data.

The Bench Press Grip Width Does Not Affect the Number of Repetitions Performed at Different Velocity Loss Thresholds.

This study aimed (I) to compare the number of repetitions that can be completed to failure (XRM) and before reaching a 15%, 30%, or 45% velocity loss threshold (XVLT) in the bench press exercise performed using different grip widths, and (II) to examine the inter-individual variability in the percentage of completed repetitions with respect to the XRM when the set volume is prescribed based on a fixed number of repetitions (FNR) and several velocity loss thresholds (VLT). Nineteen men performed four separate sessions in a random order where there was a single set of repetitions completed to failure against 75% of the one-repetition maximum during the Smith machine bench press exercise using a narrow, medium, wide, or self-selected grip widths. The XRM (p = 0.545) and XVLTs (p ≥ 0.682) were not significantly affected by grip width. A high and comparable inter-individual variability in the percentage of completed repetitions with respect to the XRM was observed when using both an FNR (median CV = 24.3%) and VLTs (median CV = 23.5%). These results indicate that Smith machine bench press training volume is not influenced by the grip width and that VLTs do not allow a more homogeneous prescription of the set volume with respect to the XRM than the traditional FNR.

Comparing the effects of resistance exercise type on serum levels of oxidative stress and muscle damage markers in resistance-trained women

The aim of the current study is to compare the effects of hypertrophy-, strength-, and power-type resistance exercise training types on hydrogen peroxide (H2O2), malondialdehyde (MDA), total lactate dehydrogenase (LDH), and total creatine kinase (CK) in resistance-trained women. After determining one-repetition maximum (1-RM), ten resistance-trained women (age 26.30 ± 4.95 years; body mass index 22.07 ± 2.02 kg/m2; body fat 24.64 ± 4.98%) conducted hypertrophy-type (70% of 1-RM), strength-type (90% of 1-RM), and power-type (45% of 1-RM) resistance exercise for three consecutive weeks. The movements included lever leg extension, reverse-grip lat pull-down, horizontal leg press, standing biceps cable curl, lying leg curl, machine bench press, standing cable triceps extension, and seated calf raises. Fasting blood samples were obtained immediately before and immediately after each trial. Statistical analyses were performed using the t test, Wilcoxon, and analysis of covariance. The significance level was set at P < 0.05 level. The results indicated that one bout of hypertrophy-, strength-, and power-type resistance exercises had no significant effects on H2O2, MDA, and total LDH levels. However, serum total CK level significantly increased after all the three types of resistance exercise. Power resistance exercise resulted in a higher total CK level than hypertrophy and strength types. Although the three types of hypertrophy, strength, and power exercise cause muscle damage, they do not exacerbate oxidative stress in resistance-trained women.

Effect of pre-fatiguing the triceps brachii on subsequent strength performance and myoelectric activity in the barbell, dumbbell and Smith machine bench press

Objective: The purpose of this study was to examine the effect of pre-fatiguing the triceps brachii on subsequent strength performance and myoelectric activity in the barbell, dumbbell, and Smith machine bench press.&#x0D; Method: Nineteen trained men participated of this study (27.9 ± 4.5 years; 1.72 ± 0.1 m; 80.3 ± 9.2 kg). Ten-repetition maximum loads were determined for the triceps extension as well as the barbell barbell, dumbbell and Smith machine bench press. Three experimental protocols were performed in a randomized design. All experimental protocols began with four sets of the triceps extension (performed with a high pulley) to repetition failure followed by four sets to repetition failure for one of three bench press modalities. Two minute-rest intervals were adopted between sets and exercises. Total repetitions (work), training volume and myoelectric activity of pectoralis major, anterior deltoid, biceps brachii, and triceps brachii were recorded during each bench press modality.&#x0D; Results: Significantly greater activity of the biceps brachii was observed during performance of the dumbbell bench press versus barbell and Smith machine bench press. No other significant differences were observed between protocols.&#x0D; Conclusion: Therefore, considering the training volume and myoelectric activity of the synergistic muscles, similar performance across bench press modalities can be expected when preceded by performance of a triceps extension.

Longer Concentric Action Increases Muscle Activation and Neuromuscular Fatigue Responses in Protocols Equalized by Repetition Duration.

Lacerda, LT, Costa, CG, Lima, FV, Martins-Costa, HC, Diniz, RCR, Andrade, AGP, Peixoto, GHC, Bemben, MG, and Chagas, MH. Longer concentric action increases muscle activation and neuromuscular fatigue responses in protocols equalized by repetition duration. J Strength Cond Res 33(6): 1629-1639, 2019-The aim of this study was to investigate the impact of protocols equalized by the repetition duration but composed of different concentric (CON) and eccentric (ECC) durations on muscle activation and neuromuscular fatigue. Seventeen males with previous experience in resistance training performed 3 training protocols (A - 2 second CON: 4 second ECC; B - 3 second CON: 3 second ECC; and C - 4 second CON: 2 second ECC) with the Smith machine bench press exercise, all with 3 sets, 6 repetitions, 3 minutes' rest, and 60% of 1RM. The normalized root mean square of the electromyographic signal (EMGRMS) and mean frequency electromyography (EMGMF) for pectoralis major and triceps brachii muscles were calculated for second and fifth repetitions in each set. The results showed an EMGMF decrease across the repetitions accompanied by a progressive increase of the EMGRMS across the repetitions for all protocols and muscles. The EMGRMS was higher in protocol C when compared with protocol A and B for pectoralis major. The EMGMF was lower in protocols B and C than in protocol A for pectoralis major throughout the sets and repetitions. A higher EMGRMS and a lower EMGMF were observed in protocols B and C compared with protocol A for triceps brachii, solely in the fifth repetition. In conclusion, training protocols conducted with the same repetition duration, but with different concentric and eccentric durations, produce distinct muscle activation and neuromuscular fatigue responses, in which performing longer concentric durations could be the more appropriate strategy to increase muscle activation and neuromuscular fatigue.

A Smart Bench Press Machine: Automatic Weight Control Sensitive to User Tiredness

In order to provide a safe free-weight-training environment to people without workout trainers, we suggest a smart bench press machine with an automatic weight control system sensitive to user tiredness. Physical weight plates on the machine are replaced with a hydraulic cylinder as a press load and the cylinder knob is coupled with a step motor to change its tensile force automatically in-between lifting exercises. Three subjects participated to verify the usability of the smart bench press machine. They were asked to lift a 6-RM press load 10 times with 3 different lifting conditions: 1) no assistance, 2) a human assistance, and 3) the automatic weight control. All subjects were not able to complete the 10 sets without assistance due to tiredness, but they finished the full sets under the two assistive conditions. Average lifting speeds under the automatic weight control condition showed the most consistent level. Normalized quasi-tension data based on surface electromyogram signals of both Pectoralis Majors revealed that the subjects maintained the target muscle activation level above 50% but not more than 80% throughout the 10 sets. Therefore, the smart bench press machine is expected to both keep pace with the lifting exercise and reduce risk of injuries due to excessive muscle tensions.

The impact of test loads on the accuracy of 1RM prediction using the load-velocity relationship

BackgroundNumerous methods have been proposed that use submaximal loads to predict one repetition maximum (1RM). One common method applies standard linear regression equations to load and average vertical lifting velocity (Vmean) data developed during squat jumps or three bench press throw (BP-T). The main aim of this project was to determine which combination of three submaximal loads during BP-T result in the most accurate prediction of 1RM Smith Machine bench press strength in healthy individuals.MethodsIn this study combinations of three BP-T loads were used to predict 1RM Smith Machine bench press strength. Additionally, we examined whether regression models developed using peak vertical bar velocity (Vpeak), rather than Vmean, provide the most accurate prediction of Smith Machine bench press 1RM. 1RM Smith Machine bench press strength was measured directly in 12 healthy regular weight trainers (body mass = 80.8 ± 5.7 kg). Two to three days later a linear position transducer attached to the collars on a Smith Machine was used to record Vmean and Vpeak during BP-T between 30 and 70% of 1RM (10% increments).ResultsRepeated measures analysis of variance testing showed that the mean values for slope and ordinate intercept for the regression models at each of the load ranges differed significantly depending on whether Vmean or Vpeak were used in the prediction models (P < 0.001). Conversely, the abscissa intercept did not differ significantly between either measure of vertical bar velocity at each load range. The key finding in this study was that 1RM Smith Machine bench press strength can be determined with high relative accuracy by examining Vmean and Vpeak during BP-T over three loads, with the most precise models using Vpeak during loads representing 30, 40 and 50% of 1RM (R2 = 0.96, SSE = 4.2 kg).ConclusionsThese preliminary findings indicate that exercise programmers working with normal healthy populations can accurately predict Smith Machine 1RM bench press strength using relatively light load Smith Machine BP-T testing, avoiding the need to expose their clients to potentially injurious loads.

Reliability of the Load-Velocity Relationship Obtained Through Linear and Polynomial Regression Models to Predict the 1-Repetition Maximum Load.

This study aimed to compare the between-session reliability of the load-velocity relationship between (1)linear versus polynomial regression models, (2)concentric-only versus eccentric-concentric bench press variants, as well as (3)the within-participants versus the between-participants variability of the velocity attained at each percentage of the 1-repetition maximum. The load-velocity relationship of 30 men (age: 21.2 [3.8] y; height: 1.78 [0.07] m, body mass: 72.3 [7.3] kg; bench press 1-repetition maximum: 78.8 [13.2] kg) were evaluated by means of linear and polynomial regression models in the concentric-only and eccentric-concentric bench press variants in a Smith machine. Two sessions were performed with each bench press variant. The main findings were: (1)first-order polynomials (coefficient of variation: 4.39%-4.70%) provided the load-velocity relationship with higher reliability than the second-order polynomials (coefficient of variation: 4.68%-5.04%); (2)the reliability of the load-velocity relationship did not differ between the concentric-only and eccentric-concentric bench press variants; and (3)the within-participants variability of the velocity attained at each percentage of the 1-repetition maximum was markedly lower than the between-participants variability. Taken together, these results highlight that, regardless of the bench press variant considered, the individual determination of the load-velocity relationship by a linear regression model could be recommended to monitor and prescribe the relative load in the Smith machine bench press exercise.

Reliability of power and velocity variables collected during the traditional and ballistic bench press exercise

This study aimed to examine the reliability of different power and velocity variables during the Smith machine bench press (BP) and bench press throw (BPT) exercises. Twenty-two healthy men conducted four testing sessions after a preliminary BP one-repetition maximum (1RM) test. In a counterbalanced order, participants performed two sessions of BP in one week and two sessions of BPT in another week. Mean propulsive power, peak power, mean propulsive velocity, and peak velocity at each tenth percentile (20–70% of 1RM) were recorded by a linear transducer. The within-participants coefficient of variation (CV) was higher for the load–power relationship compared to the load–velocity relationship in both the BP (5.3% vs. 4.1%; CV ratio = 1.29) and BPT (4.7% vs. 3.4%; CV ratio = 1.38). Mean propulsive variables showed lower reliability than peak variables in both the BP (5.4% vs. 4.0%, CV ratio = 1.35) and BPT (4.8% vs. 3.3%, CV ratio = 1.45). All variables were deemed reliable, with the peak velocity demonstrating the lowest within-participants CV. Based upon these findings, the peak velocity should be chosen for the accurate assessment of BP and BPT performance.

Influência da ordem dos exercícios resistidos na percepção subjetiva de esforço e número de repetições em mulheres idosas

Objetivo: Avaliar a influência da ordem dos exercícios resistidos na percepção de esforço e número de repetições em mulheres idosas. Métodos: 10 idosas (68,15 ± 4,40 anos) realizaram duas sequências diferentes de exercícios resistidos para membros superiores. Sequência A (SA): Supino Vertical (SV), Puxador Frente (PF), Desenvolvimento com halteres (DES), Rosca Direta (RD) e Tríceps Pulley (TP). Sequência B (SB): ordem inversa. A percepção de esforço foi avaliada pela escala OMNI e BORG. O número de repetições em cada série dos exercícios foi registrado. Resultados: A percepção de esforço (escala OMNI) para SB (7,80 ± 1,39; p = 0,03) foi estatisticamente maior quando comparada com SA (6,70 ± 0,94) para o exercício SV, na segundo série. Por outro lado, a percepção de esforço obtida pela escala BORG demonstrou valores maiores estatisticamente na segunda série da SA (14,90 ± 2,60; p = 0,03) em relação ao SB (13,10 ± 1,59) no exercício TP. O volume de repetições no exercício SV foi significativamente maior na SA (13,30 ± 2,11; p = 0,001) em relação ao SB (11,40 ± 3,23), na segundo série. O número de repetições foi estatisticamente maior (p = 0,001) para a SB comparada com SA, na segunda e terceira séries para os exercícios RD e TP, respectivamente. Conclusão: A ordem dos exercícios resistidos em membros superiores pode influenciar no número de repetições executadas por mulheres idosas.

Chest Press Exercises With Different Stability Requirements Result in Similar Muscle Damage Recovery in Resistance-Trained Men.

Ferreira, DV, Ferreira-Júnior, JB, Soares, SRS, Cadore, EL, Izquierdo, M, Brown, LE, and Bottaro, M. Chest press exercises with different stability requirements result in similar muscle damage recovery in resistance trained men. J Strength Cond Res 31(1): 71-79, 2017-This study investigated the time course of 96 hours of muscle recovery after 3 different chest press exercises with different stability requirements in resistance-trained men. Twenty-seven men (23.5 ± 3.8 years) were randomly assigned to one of the 3 groups: (a) Smith machine bench press; (b) barbell bench press; or (c) dumbbell bench press. Participants performed 8 sets of 10 repetition maximum with 2 minutes rest between sets. Muscle thickness, peak torque (PT), and soreness were measured pre, post, 24, 48, 72, and 96 hours after exercise. There were no differences in the time course of PT or muscle thickness values of the pectoralis major (p = 0.98 and p = 0.91, respectively) or elbow extensors (p = 0.07 and p = 0.86, respectively) between groups. Muscle soreness of the pectoralis major was also not different between groups (p > 0.05). However, the Smith machine and barbell groups recovered from triceps brachii muscle soreness by 72 hours after exercise (p > 0.05), whereas the dumbbell group did not present any triceps brachii muscle soreness after exercise (p > 0.05). In conclusion, resistance-trained men experience similar muscle damage recovery after Smith machine, barbell, and dumbbell chest press exercise. However, muscle soreness of the elbow extensors takes a longer time to recover after using a barbell chest press exercise.

The Effect of Caffeine Supplementation on Power and Fatigue in Recreationally Trained College Aged Males

Caffeine (CAF) is consumed regularly by approximately 90% of adults worldwide, primarily to reduce fatigue and increase wakefulness. The benefit of caffeine consumption on athletic performance in large doses (3-9 mg/kg body weight or BW) is well documented in aerobic athletes. However, the benefits of caffeine consumption on resistance training (RT) variables such as power are less clear. PURPOSE:The purpose of this study was to investigate the effect of consumption of 7 mg/kg BW of CAF on power production in experienced, resistance trained college-aged males, who are habitual caffeine consumers. METHODS:Eighteen young, healthy college aged males (21.7 ± 2.0 yrs) were included in this double blind, placebo controlled study. Subjects performed a battery of tests that included a vertical jump (VJ), isometric squat (ISO), and Smith Machine squat (SQF) and Smith Machine bench press (BPF) to failure at 60% 1RM. Subjects consumed either 7 mg/kg BW of CAF or placebo (P), 60 minutes prior to testing. Test sessions were separated by a minimum of 7 days. Power production during VJ, SQF and BPF exercises was evaluated. Power obtained during SQF and BPF was used to find the fatigue index (F.I.). Also, force production during an ISO was assessed. A repeated measures ANOVA was used to determine differences between treatments. Significance for all analysis was set at p≤ 0.05. RESULTS:There were no significant differences between treatments (CAF vs P) in measures of VJ (3924.2 ± 617.1 vs 3930.9 ± 627.5W, p=0.925), ISO (2512.3 ± 555.8 vs 2585.3 ± 528.2N, p=0.270), SQF (36.9 ± 12.6 vs 33.6 ± 10.6%, p=0.234), or BPF (40.5 ± 12.5 vs 42.0 ± 8.3%, p=0.591). CONCLUSION:7 mg/kg BW of CAF does not improve measures of force, power, or fatigue during single-set to failure resistance training exercises in habitual caffeine users. These results indicate that CAF supplementation may be affected by training bout volume (sets x reps), due to the lack of improvement in F.I., i.e. local muscular endurance.