Impact of Movement Tempo Distribution on Bar Velocity During a Multi-Set Bench Press Exercise

The goal of the present study was to evaluate the effect of contrast tempo movement on bar velocity changes during a multi-set bench press exercise. In randomized and counter-balanced order, participants performed three sets of the bench press exercise at 60%1RM under two testing conditions: E-E where all repetitions were performed with explosive (X/0/X/0) movement tempo; and S-E where the first two repetitions were performed with a slow tempo (5/0/X/0) while the third repetition was performed with explosive movement tempo (slow, slow, explosive). Twelve healthy men volunteered for the study (age = 30 ± 5 years; body mass = 88 ± 10 kg; bench press 1RM = 145 ± 24 kg). The three-way repeated measures ANOVA (tempo × set × repetition) showed statistically significant multi-interaction effect for peak bar velocity (p < 0.01; η2 = 0.23), yet not for mean bar velocity (p = 0.09; η2 = 0.14). The post hoc results for multi-interaction revealed that peak bar velocity in the 3rd repetition was significantly higher for E-E compared to SE only during set 1 (p < 0.001). Therefore, the distribution of movement tempo had a significant impact on peak bar velocity, but not on mean bar velocity. The decrease in peak bar velocity in the 3rd repetition during the S-E condition was observed only in the first set, while such a tendency was not observed in the second and third set.

Acute effects of two caffeine doses on bar velocity during the bench press exercise among women habituated to caffeine: a randomized, crossover, double-blind study involving control and placebo conditions

Purpose The main goal of this study was to evaluate the effectiveness of two different doses of caffeine (3 and 6 mg/kg) to enhance bar velocity during the bench press in women habituated to caffeine. Methods Twelve recreationally trained women (age: 23.3 ± 0.8 years, body mass: 60.7 ± 5.7 kg, bench press one-repetition maximum (1RM): 44.3 ± 7.8 kg, daily caffeine ingestion: 5.7 ± 2.0 mg/kg/day) participated in a randomized double-blind experimental design. Each participant performed four different experimental sessions: after no supplementation (control, CON), after ingesting 3 and 6 mg/kg of caffeine (CAF-3 and CAF-6, respectively), or after ingesting a placebo (PLAC). In each experimental session, the participants performed 3 sets of 3 repetitions of the bench press exercise at 50% 1RM. Results A two-way repeated-measures ANOVA with subsequent post hoc analyses indicated significant increases in peak velocity (p < 0.01; ES = 0.91) and mean velocity (p < 0.01; ES = 0.78) after the intake of CAF-6 compared to CON. The study did not show significant differences in bar velocity between CAF-6 and PLAC and between CAF-3 and PLAC. No significant differences in bar velocity were observed between CAF-3 and CAF-6 conditions. Conclusion These results suggest that 6 mg/kg of caffeine can be an effective dose to improve power-specific training outcomes in women habituated to caffeine. However, the ergogenic effect of 6 mg/kg of caffeine may be derived from a combination of biological effects and expectancy, as this dose was only superior to the control condition with no differences over the placebo.

Acute Effects of High Doses of Caffeine on Bar Velocity during the Bench Press Throw in Athletes Habituated to Caffeine: A Randomized, Double-Blind and Crossover Study

Chronic intake of caffeine may produce a reduction in the potential performance benefits obtained with the acute intake of this substance. For this reason, athletes habituated to caffeine often use high doses of caffeine (≥9 mg/kg) to overcome tolerance to caffeine ergogenicity due to chronic intake. The main objective of the current investigation was to evaluate the effects of high caffeine doses on bar velocity during an explosive bench press throw in athletes habituated to caffeine. Twelve resistance-trained athletes, with a moderate-to-high chronic intake of caffeine (~5.3 mg/kg/day) participated in a randomized double-blind and randomized experimental design. Each participant performed three identical experimental sessions 60 min after the intake of a placebo (PLAC) or after the intake of 9 (CAF-9) or 12 mg/kg (CAF-12) of caffeine. In each experimental session, the athletes performed five sets of two repetitions of the bench press throw exercise with a load equivalent to 30% of their one-repetition maximum. In comparison to PLAC, the intake of caffeine increased peak and mean velocity (p < 0.01) during the five sets of the bench press throw exercise. There were no significant differences in peak and mean bar velocity between the two doses of caffeine (CAF-9 vs. CAF-12; p = 0.91, = 0.96, respectively). The ingestion of high doses of caffeine was effective in producing an increase in mean and peak bar velocity during the bench press throw in a group of habitual caffeine users. However, using CAF-12 did not offer additional benefits for performance with respect to CAF-9.

A tension assessment model for digital twins of continuous rolling processes

The paper deals with the calculation of interstand tensions in continuous rolling mills for flat and long products. A fast calculation method for the interstand tensions from measurable process quantities is a mcritical point to enable the construction of digital twins for the rolling process, which must be adjusted to the real-world tension behaviour of the production system. It is straightforward to calculate the effects of the tensions on roll forces, torques and the strip or bar velocity. However, the inverse problem of calculating the acting interstand tensions including their effects from the process parameters is of much greater interest but also of a higher complexity, because the interactions between all of the stands in the continuous rolling mill must be taken into account. The paper presents a mathematical model to solve the inverse problem by subsequent linearization of the tensions influences in the rolling mill.Extra nonlinearities are taken into account by modeling the tension-dependent spread by an empirical model. The overall model is solved by an iteration method to yield a fully compatible solution for the constant volume flux as well as the force and torque equilibria in the roll gaps. Results are shown for the tension distributions in strip and rod mills. The results indicate that the present friction conditionsand the spreading behaviour of the rolled material have a high impact on the tension distributions.

The Effects of Ischemia During Rest Intervals on Bar Velocity in the Bench Press Exercise With Different External Loads

The main aim of the present study was to evaluate the acute effects of ischemia used during rest periods on bar velocity changes during the bench press exercise at progressive loads, from 20 to 90% of 1RM. Ten healthy resistance trained men volunteered for the study (age = 26.3 ± 4.7 years; body mass = 89.8 ± 6.3 kg; bench press 1RM = 142.5 ± 16.9 kg; training experience = 7.8 ± 2.7 years). During the experimental sessions the subjects performed the bench press exercise under two different conditions, in a randomized and counterbalanced order: (a) ischemia condition, with ischemia applied before the first set and during every rest periods between sets, and (b) control condition where no ischemia was applied. During each experimental session eight sets of the bench press exercise were performed, against loads starting from 20 to 90% 1RM, increased progressively by 10% in each subsequent set. A 3-min rest interval between sets was used. For ischemia condition the cuffs was applied 3 min before the first set and during every rest period between sets. Ischemia was released during exercise. The cuff pressure was set to ∼80% of full arterial occlusion pressure. The two-way repeated measures ANOVA showed a statistically significant interaction effect for peak bar velocity (p = 0.04) and for mean bar velocity (p = 0.01). There was also a statistically significant main effect of condition for peak bar velocity (p &lt; 0.01) but not for mean bar velocity (p = 0.25). The post hoc analysis for interaction showed significantly higher peak bar velocity for the ischemia condition compared to control at a load of 20% 1RM (p = 0.007) and at a load of 50% 1RM (p = 0.006). The results of the present study indicate that ischemia used before each set even for a brief duration of &lt;3 min, has positive effects on peak bar velocity at light loads, but it is insufficient to induce such effect on higher loads.

The effects of different intra-set velocity loss thresholds on lower-limb adaptations to resistance training in young adults: A systematic review and meta-analysis

Background: The level of effort seems to play a key role in determining neuromuscular adaptations; however, less is known regarding the optimal dose-response for intra-set levels of effort on chronic resistance training (RT) adaptations. Objective: We aimed to synthesize the current literature on chronic RT adaptations in response to different intra-set velocity loss (VL) thresholds in the back squat exercise. We investigated changes in muscle strength, muscular endurance, sports-related physical performance, and muscle hypertrophy outcomes during resistance exercise to establish optimal dose-response relationships in physically active individuals.Methods: We conducted a literature search using PubMed (Medline), Web of Science™, Scopus, and Cochrane up to April 2021, with no restriction on year of publication. The inclusion criteria were based on the PICO strategy. A random-effect meta-analysis was performed to determine the standardized mean differences (SMD ± 95% confidence intervals) for different intra-set VL thresholds (low VL [&lt; 15%], moderate VL [≥ 15% and &lt; 30%], and high VL [≥ 30%]) in RT on maximum muscular strength, bar velocity against submaximal loads, endurance against a given load, countermovement jump height, running sprint time, and muscle hypertrophy. Results: A total of 4,031 articles were found and 11 studies met our eligibility criteria. Pooled results revealed improvements between pre- and post-training intervention in 1RM strength (SMD = 0.78; p &lt; 0.001); bar velocity outputs (light-loads [SMD = 0.79; p &lt; 0.001] and heavy-loads [SMD = 2.08; p &lt; 0.001]); endurance against a given load (SMD = 1.21; p &lt; 0.001); countermovement jump height (SMD = 0.50; p &lt; 0.001); running sprint time (SMD = - 0.28; p = 0.001); and muscle hypertrophy (SMD = 0.31; p = 0.05), with no significant difference between VL thresholds (p &gt; 0.05). However, low VL elicited greater within-group SMD for 1RM strength than moderate and high VL thresholds (SMD = 0.93; 0.72; and 0.75; for low, moderate, and high VL thresholds, respectively). Low and moderate VL thresholds resulted in greater within-group SMD than high VL thresholds for velocity against light loads (SMD for low VL = 0.89; moderate VL = 0.90; high VL = 0.59); countermovement jump height (SMD for low VL = 0.51; moderate VL = 0.58; high VL = 0.36); and running sprint time (SMD for low VL = -0.49; moderate VL = -0.32; high VL = -0.09). Moderate and high VL thresholds induced higher within-group SMD for muscle hypertrophy than low VL (SMD for low VL = 0.14; moderate VL = 0.40; high VL = 0.44). Conclusions: Low to moderate VL thresholds may provide more effective and efficient training stimuli for improving performance in strength-power tasks, due to the similar or even greater chronic adaptations achieved compared with high VL, despite the lower number of repetitions performed during the RT program. Conversely, moderate to high VL may provide more favorable training stimuli for inducing muscle hypertrophy. Strength coaches may apply these dose-response trends to design optimal RT stimuli based on their specific training goals. Protocol registration: The study protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020189321).

Acute Effects of Different Blood Flow Restriction Protocols on Bar Velocity During the Squat Exercise

The main goal of the present study was to evaluate the effects of different blood flow restriction (BFR) protocols (continuous and intermittent) on peak bar velocity (PV) and mean bar velocity (MV) during the squat exercise at progressive loads, from 40 to 90% 1RM. Eleven healthy men (age = 23.4 ± 3.1 years; body mass = 88.5 ± 12.1 kg; squat 1RM = 183.2 ± 30.7 kg; resistance training experience, 5.7 ± 3.6 years) performed experimental sessions once a week for 3 weeks in random and counterbalanced order: without BFR (NO-BFR), with intermittent BFR (I-BFR), and with continuous BFR (C-BFR). During the experimental session, the participants performed six sets of the barbell squat exercise with loads from 40 to 90% 1RM. In each set, they performed two repetitions. During the C-BFR session, the cuffs were maintained throughout the training session. During the I-BFR, the cuffs were used only during the exercise and released for each rest interval. The BFR pressure was set to ∼80% arterial occlusion pressure (AOP). Analyses of variance showed a statistically significant interaction for MV (p &lt; 0.02; η2 = 0.18). However, the post hoc analysis did not show significant differences between particular conditions for particular loads. There was no significant condition × load interaction for PV (p = 0.16; η2 = 0.13). Furthermore, there were no main effects for conditions in MV (p = 0.38; η2 = 0.09) as well as in PV (p = 0.94; η2 = 0.01). The results indicate that the different BFR protocols used during lower body resistance exercises did not reduce peak bar velocity and mean bar velocity during the squat exercise performed with various loads.

Predicting performance on the NFL-225 bench press test using bar velocity

BACKGROUND: Bar velocity has been proved to accurately predict performance in several exercises. OBJECTIVE: To estimate the total number of repetitions during the NFL-225 Bench Press Test (NFL-225) based on bar velocity in collegiate football players. METHODS: Forty-six NCAA Division I football players performed as many bench press repetitions as possible with a standard load of 225 lbs. The variables used to estimate the total number of repetitions were: mean velocity of the fastest repetition achieved in the test (FR); mean velocity of the first repetition (V1); mean velocity of the first three repetitions (MV3); mean velocity of the first five repetitions (MV5); and mean velocity of the first 10 repetitions (MV10). Linear regression analyses were conducted to predict NFL-225 performance based on bar velocity. RESULTS: The prediction of the total number of repetitions was similar between the five mean velocities (FR: R2= 0.64, SEE = 3.87, V1: R2= 0.65, SEE = 3.80, MV3: R2= 0.70, SEE = 3.52, MV5: R2= 0.71, SEE = 3.48, and MV10: R2= 0.62, SEE = 3.37). CONCLUSION: The mean velocities allowed the production of general regression equations for the estimation of the total number of repetitions in the NFL-225. V1 and MV3 presented as the best options due to their accuracy, time-efficiency, and reduced musculoskeletal stress.

The Acute Post-Activation Performance Enhancement of the Bench Press Throw in Disabled Sitting Volleyball Athletes

The purpose of the present study was to examine the acute effects of the bench press exercise with predetermined velocity loss percentage on subsequent bench press throw (BPT) performance with raised legs or feet on the floor among disabled, sitting volleyball players. Twelve elite sitting volleyball athletes (age = 33 ± 9 years; body mass = 84.7 ± 14.7 kg; relative bench press maximum strength = 1.0 ± 0.3 kg/body mass) took part in this study. The experiment was performed following a randomized crossover design, where each participant performed a single set of bench press with a 60% one-repetition maximum (1RM) to a 10% decrease of mean bar velocity as a conditioning activity (CA). The BPT with a 60%1RM was performed to assess changes in peak power (PP), peak velocity (PV) before and after the CA. The differences between analyzed variables before and after the CA were verified using two-way repeated-measures ANOVA (condition × time; 2 × 2). The ANOVA showed a significant main effect of time for peak bar velocity (p = 0.03; η2 = 0.312) and peak power output (p = 0.037; η2 = 0.294). The post hoc comparison showed a significant increase in post-CA peak bar velocity and peak power for raised legs condition in comparison with pre-CA value (p = 0.02, p = 0.041, respectively). The present study showed that the subsequent BPT performed with raised legs could be enhanced by the bench press with a 60% 1RM to a 10% mean bar velocity decrease as a CA among disabled sitting volleyball players. Therefore, athletes and coaches can consider performing a bench press throw with raised legs without compromising performance.