Barbell Velocity Research Articles

A Cluster Set Protocol in the Half Squat Exercise Reduces Mechanical Fatigue and Lactate Concentrations in Comparison with A Traditional Set Configuration.

Splitting sets into clusters has been shown to maintain performance during resistance training. This study compared the acute fatigue produced by a traditional (TSC) versus a cluster (CSC) set configuration in the smith machine half squat exercise. Fifteen males performed a single bout of TSC and CSC separated by 72–96 h. In the TSC, participants performed as many repetitions as possible until reaching a 20% drop in barbell velocity (MPV), while in the CSC, they performed the same number of repetitions with 15 seconds inter-repetition rest. Effects of both protocols in MPV, countermovement jump height (CMJ), and blood lactate (BLa) were measured. Significant differences between protocols were found for MPV of the last repetition (0.4 vs 0.5 m/s TSC and CSC) and BLa (6.8 mmol/L vs 3.2 mmol/L TSC and CSC). Significant drop of velocity from the first to the last repetition of the set (19.9%), decrease in CMJ height (35.4 vs 32.6 cm), and increase in BLa (2.1 vs 6.8 mmol/L) pre–post-exercise was observed just for the TSC protocol. The results of the present study showed that CSC reduces the lactate response and mechanical fatigue produced by a single set on the half squat exercise in comparison with TSC.

THE CONDITIONS FOR TRANSITING TO THE STAGE OF PERFORMANCE ENHANCEMENT IN 14–15-YEAR OLD WRESTLERS

Aim. The purpose of the article is searching for conditions in the training process for forming a permanent part of motor coordination typical for a competitive technique during the growth spurt. Materials and methods. Body length and body weight were measured in 2 groups of young males on an annual basis. The first group consisted of non-athletes (n = 18), the second group comprised of young weightlifters (n = 18). The examination was conducted in the following age groups: from 10 to 13 years and from 14 to 16 years. Body composition was assessed through the Matejko method. Special fitness was measured by the barbell velocity during the lift established with the help of the photoelectron device based on a transmitter (optical quantum generator), a photodetector, and a recording device. Using the correlation between the factual and model values of minimum fixation speed the efficiency of motor coordination was assessed in the range of 60–100% of barbell weight. These correlations were also used for establishing a limiting character of technique and strength. Results. The analysis of body weight during the annual cycle showed the change in weight categories. This reflected athletes’ weight gain while preserving their qualification. An earlier increase in general growth in young weightlifters has been established, which confirms the advisability of early specialization. It was found that when performing a jerk, the minimum fixation speed of the barbell increases with increasing body length. The insufficiency of this indicator compared to qualified athletes is compensated by an increase in the importance of the muscle factor, which reduces the reliability of motor actions. A training technique is proposed aimed at a more effective implementation of motor skills and a decrease in the barbell speed based on pedagogical instruction and information on the barbell speed. This resulted in a statistically significant (t = 2.89; p < 0.05) increase in the number of successful barbell lifts. Conclusion. When doing weightlifting, it is necessary to stimulate general growth and the growth of muscle mass with training loads being a leading factor in sports results. The training process combined with pedagogical instruction forms a stable motor skill and a reasonable transition to the stage of performance enhancement.

Autoregulation in Resistance Training: A Comparison of Subjective Versus Objective Methods.

Shattock, K and Tee, JC. Autoregulation in resistance training: A comparison of subjective versus objective methods. J Strength Cond Res 36(3): 641-648, 2022-Autoregulation (AR) is a resistance training periodization approach that adjusts training prescription in response to individual rates of athlete adaptation. AR training prescription can make use of either subjective (rating of perceived exertion [RPE]) or objective (barbell velocity) intensity descriptors. The aim of this research was to compare the efficacy of these 2 approaches in improving sport-specific physical performance measures. Using a randomized crossover design, 20 amateur rugby union players completed two 6-week blocks of training with training intensity prescribed using either objective velocity-based (VB) (measured using a wearable accelerometer device) or objective RPE-based intensity prescriptions. Training volume was matched for both groups while training intensity was equivalent but prescribed using either VB or RPE measures. Performance measurements were countermovement jump (CMJ), 1 repetition maximum back squat and bench press, and 10-, 20-, and 40-m sprint. Testing was conducted before and immediately after each training block. The likelihood that observed changes in performance measures were meaningful was assessed using magnitude-based decisions. Both training programs induced practically meaningful improvements in CMJ (VB most likely +8.2, ±1.1%; RPE likely +3.8, ±0.9%), back squat (VB most likely +7.5, ±1.5%; RPE possibly +3.5, ±1.8%), and bench press (VB most likely +7.7, ±2.1%; RPE possibly +3.8, ±0.9%). Changes in sprint test performance were very likely trivial for both programs. Objective AR programming resulted in larger improvements in CMJ (likely 4.2, ±1.2%), squat (likely 3.7, ±1.5%) performance, and bench press (possibly 3.7, ±1.5%) performance. Autoregulation periodization improved strength and CMJ, but not sprint performance. Autoregulation effects are augmented through the use of objective intensity prescription.

Test-Retest Reliability Between Free Weight and Machine-Based Movement Velocities.

Miller, RM, Freitas, EDS, Heishman, AD, Koziol, KJ, Galletti, BAR, Kaur, J, and Bemben, MG. Test-retest reliability between free weight and machine-based movement velocities. J Strength Cond Res 34(2): 440-444, 2020-Several devices are available to measure muscular power through velocity measurement, including the Tendo FitroDyne. The ability for such devices to produce consistent results is still questioned, and the reproducibility of measurement between free weight and machine exercise has yet to be examined. Therefore, the aim of this investigation was to determine the test-retest reliability for barbell velocity during the bench press (BP) and weight velocity during the 2 leg press (2LP) for loads corresponding to 20-80% of 1 repetition maximum (1RM). Forty recreationally active individuals (22.6 ± 2.5 years; 175.9 ± 10.8 cm; and 76.2 ± 13.2 kg) with a 1RM BP and 2LP of 66.8 ± 32.4 kg and 189.5 ± 49 kg, respectively, volunteered for this study. Subjects completed 1 familiarization visit preceding 3 testing visits, which encompassed 1RM determination and 2 days of velocity testing. Forty-eight hours after 1RM testing, the subjects performed 1 repetition at 20, 30, 40, 50, 60, 70, and 80% of their 1RM for each exercise in randomized order. Subjects returned to the laboratory 1 week later to perform the velocity assessment again in randomized order. Intraclass correlation coefficient (ICC2,1) and relative SEM for the BP and 2LP ranged from 0.56 to 0.98 (3-18.1%) and 0.78 to 0.98 (2.8-7.2%), respectively, and no mean differences were observed between trials. The results suggest high reliability for BP velocity between 30 and 60% 1RM and moderate reliability at 20, 70, and 80% 1RM, while the 2LP displayed high to excellent reliability from 20 to 80% 1RM. Cumulatively, machine-based exercise displayed greater reproducibility; however, additional machine exercises need to be examined to bolster this conclusion.

Health Ramifications of Smart Devices

ABSTRACT Smart devices, such as smartphones, smartwatches, and tablets, have rapidly become more popular in the fitness industry and provide a variety of benefits ranging from tracking barbell velocity to displaying online training programs. These devices use cellular data and Wi-Fi to transmit information, which have shown to potentially pose risks to our health. The purpose of this article is to both (a) provide the reader with researched information on how the use of smart devices may pose a risk to our health and (b) provide practical applications for how to reduce the health risks from using these devices. For a video abstract of this article, see Supplemental Digital Content 1, http://links.lww.com/SCJ/A274.

Reliability and Criterion Validity of the Assess2Perform Bar Sensei.

The Assess2Perform Bar Sensei is a device used to measure barbell velocity for velocity-based training that has not yet been validated. The purpose of this study was to determine criterion validity and reliability of the Assess2Perform Bar Sensei in barbell back squats by comparing it against the GymAware PowerTool, a previously validated instrument. Sixteen injury-free, resistance-trained subjects (eleven males and five females) were recruited. Subjects were tested for their back squat one repetition maximum (1RM). Then, on two separate days, subjects performed two sets of three repetitions at loads of 45%, 60% and 75% 1RM. The GymAware PowerTool and Bar Sensei were attached to the barbell in similar locations for concurrent collection of mean concentric velocity (MCV) and peak concentric velocity (PCV). The Bar Sensei and PowerTool showed generally fair to poor agreement for MCV and PCV when subjects lifted 45% of 1RM (intraclass correlation;ICC 0.4–0.59), and they showed poor agreement when subjects lifted 60% and 75% of 1RM (ICC 0.3–0.4). Inter-repetition/within-set reliability for the Bar Sensei ranged between ICC = 0.273–0.451 for MCV and PCV compared to the far more reliable PowerTool (ICC = 0.651–0.793). Currently, the Bar Sensei is not a reliable or valid tool for measuring barbell velocity in back squats.

Effects of Attentional Focus and Dual-tasking on Conventional Deadlift Performance in Experienced Lifters

Background: Previous attentional focus literature suggests that adopting an external focus (EF) results in greater force production through a variety of mechanisms. Objective: The purpose of the present study was to examine the effects of attentional focus and dual-tasking when performing heavily loaded barbell movements that are specific to strength-based sports. Method: Fifteen resistance-trained males (age = 23.3 ± 3.4 years) reported to the laboratory for three visits. The first visit consisted of a five-repetition maximum (5RM) test on the conventional deadlift. During the subsequent sessions, the participants performed a total of twelve single conventional deadlift repetitions while adopting an internal focus (IF), an external focus (EF), or while performing the cognitive task (COG). The IF and EF consisted of focusing on activating the quadriceps and maintaining a straight bar path, respectively. The COG consisted of counting the total occurrence of two single-digits in a sequence of three-digit numbers, separately. Three-dimensional motion capture and force platforms were used to collect kinematic and kinetic data. Results: No significant differences were found between the IF, the EF and the COG for lift duration, peak barbell velocity, peak vertical ground reaction force, area of 95% confidence ellipse, peak hip moments and peak hip powers. Adopting an EF significantly reduced variability of the barbell trajectory and centre of pressure (COP) in the anterior-posterior direction. Mean velocity of COP was also significantly lower for the EF. Conclusion: Our findings suggest that adopting an EF may lead to greater postural stability when performing heavily loaded barbell movements.

Barbell velocity: a practical and precise method for predicting bench press strength in sedentary women.

Bench press one-repetition maximum (BP1RM) prediction models offer a timely approach to predict BP1RM while avoiding the limitations with traditional BP1RM testing. Interestingly, no models have determined the ability for a traditional weight, the 20.5 kg barbell, to predict BP1RM strength. Few models have exclusively examined females and sedentary individuals, leaving the accuracy of these models unknown for these populations. Therefore, this investigation sought to examine the ability for 20.5 kg barbell velocity to predict BP1RM in sedentary females. Nineteen sedentary females (21.79±1.43 years, 166.08±7.76 cm, 63.98±7.54 kg, 31.57±4.72 BP1RM) completed BP1RM testing and completed two additional visits to determine 20.5 kg barbell velocity from a single repetition separated by 7-10 days. Nineteen additional females (21.39±1.09 years, 164.31±7.37 cm, 67.34±9.32 kg, 32.75±5.09 BP1RM) served as a cross-validating group completing identical testing procedures. Regression analyses revealed that 20.5 kg barbell velocity accounted for 95% of the variance in BP1RM strength while presenting marginal standard error (1.34 kg) and mean absolute error (0.97 kg), with similar values observed in the cross-validating group (SEE: 2.13 kg, MAE: 1.56 kg). Predicted BP1RM values were not significantly different from actual BP1RM (P=0.43) nor were measures in barbell velocity between trials 1 and 2 (P=0.57), while displaying high reliability (ICC: 0.81). Measure bias between BP1RM methods was 0.449±1.651kg and the agreement between methods varied between -2.78 kg less and 0.3686 kg greater for 95% of the participants. The present data provides an accurate prediction model regarding BP1RM for sedentary females. These findings can reduce the limitations associated with traditional BP1RM testing while providing a practical and accurate BP1RM approximation with marginal error.

Acute Enhancement of Jump Performance, Muscle Strength, and Power in Resistance-Trained Men After Consumption of Caffeinated Chewing Gum.

To explore the acute effects of caffeinated chewing gum on vertical-jump performance, isokinetic knee-extension/flexion strength and power, barbell velocity in resistance exercise, and whole-body power. Nineteen resistance-trained men consumed, in randomized counterbalanced order, either caffeinated chewing gum (300mg of caffeine) or placebo and completed exercise testing that included squat jump; countermovement jump; isokinetic knee extension and knee flexion at angular velocities of 60 and 180°·s-1; bench-press exercise with loads corresponding to 50%, 75%, and 90% of 1-repetition maximum (1RM); and an "all-out" rowing-ergometer test. Compared with placebo, caffeinated chewing gum enhanced (all Ps < .05) (1)vertical-jump height in the squat jump (effect size [ES] = 0.21; +3.7%) and countermovement jump (ES = 0.27; +4.6%); (2)knee-extension peak torque (ES = 0.21; +3.6%) and average power (ES = 0.25; +4.5%) at 60°·s-1 and knee-extension average power (ES = 0.30; +5.2%) at 180°·s-1, and knee-flexion peak torque at 60°·s-1 (ES = 0.22; +4.1%) and 180°·s-1 (ES = 0.31; +5.9%); (3)barbell velocity at 50% of 1RM (ES = 0.30; +3.2%), 75% of 1RM (ES = 0.44; +5.7%), and 90% of 1RM (ES = 0.43; +9.1%); and (4)whole-body peak power on the rowing-ergometer test (ES = 0.41; +5.0%). Average power of the knee flexors did not change at either angular velocity with caffeine consumption. Caffeinated chewing gum with a dose of caffeine of 300mg consumed 10 min preexercise may acutely enhance vertical-jump height, isokinetic strength and power of the lower-body musculature, barbell velocity in the bench-press exercise with moderate to high loads, and whole-body power.

Visual Feedback Attenuates Mean Concentric Barbell Velocity Loss and Improves Motivation, Competitiveness, and Perceived Workload in Male Adolescent Athletes.

Weakley, JJS, Wilson, KM, Till, K, Read, DB, Darrall-Jones, J, Roe, GAB, Phibbs, PJ, and Jones, B. Visual feedback attenuates mean concentric barbell velocity loss and improves motivation, competitiveness, and perceived workload in male adolescent athletes. J Strength Cond Res 33(9): 2420-2425, 2019-It is unknown whether instantaneous visual feedback of resistance training outcomes can enhance barbell velocity in younger athletes. Therefore, the purpose of this study was to quantify the effects of visual feedback on mean concentric barbell velocity in the back squat and to identify changes in motivation, competitiveness, and perceived workload. In a randomized-crossover design (Feedback vs. Control), feedback of mean concentric barbell velocity was or was not provided throughout a set of 10 repetitions in the barbell back squat. Magnitude-based inferences were used to assess changes between conditions, with almost certainly greater differences in mean concentric velocity between the Feedback (0.70 ± 0.04 m·s) and Control (0.65 ± 0.05 m·s) observed. In addition, individual repetition mean concentric velocity ranged from possibly (repetition number 2: 0.79 ± 0.04 vs. 0.78 ± 0.04 m·s) to almost certainly (repetition number 10: 0.58 ± 0.05 vs. 0.49 ± 0.05 m·s) greater when provided feedback, whereas almost certain differences were observed in motivation, competitiveness, and perceived workload, respectively. Providing adolescent male athletes with visual kinematic information while completing resistance training is beneficial for the maintenance of barbell velocity during a training set, potentially enhancing physical performance. Moreover, these improvements were observed alongside increases in motivation, competitiveness, and perceived workload providing insight into the underlying mechanisms responsible for the performance gains observed. Given the observed maintenance of barbell velocity during a training set, practitioners can use this technique to manipulate training outcomes during resistance training.

Inter- and intra-individual variability in the kinematics of the back squat

The purpose of this study was to explore the level of inter- and intra-individual variability in the kinematic profiles of the back squat movement among skilled weightlifters. Ten competitive weightlifters volunteered for participation in this study. Barbell velocity (VBarbell) and angular velocity of the ankle (ωAnkle), knee (ωKnee) and hip joint (ωHip) were obtained by kinematic recording of six trials at 90% of 1RM in the back squat. Inter-individual variability was assessed by analysing inter-individual differences in the velocity curves through the statistical parametric mapping method. Intra-individual variability was assessed through a correlation analysis between the barbell velocity curves of each trial for each participant. Partial least squares regression analysis, was performed to relate changes in intra-individual variability to movement and anthropometric characteristics. Significant inter- and intra-individual differences were identified in VBarbell, ωAnkle, ωKnee, and ωHip (p ≤ 0.05). Having a short trunk and thigh, and a long shin in combination with greater anterior-posterior displacement of the barbell and slower velocities during the acceleration phase increased intra-individual movement consistency over movement variability. The results of the present study clearly demonstrate that skilled weightlifters display both significant inter- and intra-individual variability in the successful execution of the back squat.

Validity and reliability assessment of 3-D camera-based capture barbell velocity tracking device

Velocity-based training (VBT) requires the monitoring of lift velocity plus the prescribed resistance weight. A validated and reliable device is needed to capture the velocity and power of several exercises. ObjectivesThe study objectives were to examine the validity and reliability of the Elite Form Training System® (EFTS) for measures of peak velocity (PV), average velocity (AV), peak power (PP), and average power (AP). DesignValidity of the EFTS was assessed by comparing measurements simultaneously obtained via the Qualisys Track Manager software (C-motion, version 3.90.21, Gothenburg, Sweden) utilizing 6 motion capture cameras (Oqus 400, 240 Hz, Gothenburg, Sweden). MethodsSix participants performed 6 resistance exercises in 2 sessions: power clean, dead lift, bench press, back squat, front squat, and jump squat. ResultsSimple Pearson correlations indicated the validity of the device (0.982, 0.971, 0.973, and 0.982 for PV, AV, PP, and AP respectively) and ranged from 0.868 to 0.998 for the 6 exercises. The test-retest reliability of the EFTS was shown by lack of significant change in the Pearson correlation (<0.3% for each variable) between the 2 sessions. The multiple count error rate was 2.0% and the missed count error rate was 2.1%. ConclusionsThe validity and reliability of the EFTS were classified as excellent across all variables and exercises with only one exercise showing a slight influence by the velocity of the movement.

Validity and reliability of Gyko Sport for the measurement of barbell velocity on the bench-press exercise.

The aim of this study was to examine the validity and reliability of the novel inertial measurement unit (named: Gyko Sport) for the measurement of barbell concentric velocity on the bench-press exercise. Ten under-16 (U16) basketball players performed 2 repetitions of the bench press exercise with 6 different loads (40, 50, 60, 70, 80 and 90% of one repetition maximum [1-RM]; N.=120 repetitions). Mean velocity for each repetition was simultaneously recorded using the Gyko Sport and SmartCoach linear transducer. Results showed a very large correlation between the SmartCoach and Gyko Sport (r=0.79; standard error of estimate [SEE]=0.18 m/s). Furthermore, there was a very high agreement between both devices for the measurement of the mean velocity (intraclass correlation coefficient [ICC]=0.774; Cronbach's alpha [α]=0.872; Bland-Altman Plots [R2]=0.070). The Gyko Sport registered similar, but slightly higher values than the SmartCoach (P=0.103; mean difference 0.075±0.05 m/s). The results support the use of the Gyko Sport as an affordable, portable, and suitable wearable device to measure mean velocity on bench press exercise.

Reliability of Barbell Velocities Recorded from the GymAware Device during Squat and Bench Press Exercises

PURPOSE: To assess the reliability of velocities recorded with the GymAware linear position transducer (LTP) during the squat and bench press exercises. METHODS: Thirteen resistance-trained men (age: 21.7±0.4 years; height 1.74±0.07 m; mass: 82.9±9.5 kg; 1-repetition maximum (1RM) back squat: 149.9±20.7 kg; bench 1RM: 114.8±18.5 kg.) performed three trials of squat and bench press using the following percentages of 1RM: 20, 30, 40, 50, 60, 70, 80%. The order of the loads was counterbalanced across the participants. The mean vertical velocity of the barbell during the concentric phase of each repetition was recorded using a 3-D motion analysis system (Vicon; 200 Hz) and the GymAware LTP. Reliability of the GymAware was determined using intraclass correlations (ICC) and coefficients of variance (CV%). RESULTS: The GymAware showed high intersession reliability for both exercises with ICCs ranging from good to excellent (squat: 0.71-0.91; bench press: 0.83-0.91). CV% showed precision in the recorded velocities during both exercises (squat: 3.6%-5.8%; bench press: 4.9%-7.4%). CONCLUSION: The GymAware LTP shows high intersession reliability for recorded velocities during the squat and bench press exercises.

Validity of Barbell Velocities Recorded from the GymAware Device during Squat and Bench Press Exercises

Validity of Barbell Velocities Recorded from the GymAware Device during Squat and Bench Press Exercises

Effects of plyometric and pull training on performance and selected strength characteristics of junior male weightlifter

Purpose: The aim of this study was to investigate the effect of plyometric and pull training added an Olympic weightlifting training program (twice a week for 8 wk) on performance and selected strength characteristics in junior male weightlifter. Material: The participants [n = 34; age: 16.03 ± 0.9 y; mass: 74.78 ± 14.86 kg; height: 170.53 ± 6.81 cm] were randomized into a pull (n = 11), a plyometric (n = 12), and a control (n= 11) groups. The groups trained 6 days a week during the 8-week study period. The pull group performed four pull exercises and the plyometric group performed four plyometric exercises added to Olympic weightlifting program for 2 days a week, and the control group performed an Olympic weightlifting program alone. Analysis of variance and Magnitude-based inferences used to determine whether a significant difference existed among groups on snatch clean and jerk total (SCT), squat (SQ), back strength (BS), countermovement jump (CMJ), 30 sec. repeated jump height (RJH) and peak barbell velocity (PV). Results: The ANOVA showed a time × group interaction for SCT, BS and RJH. The MBI indicated positive changes for SCT in control group, for BS in pull group and for RJH in plyometric group. The results for the PV decrease in plyometric and pull group indicated no significant time × group interaction, but there was a significant main effects. ASK "Inserisci l'aim" \* MERGEFORMAT ASK \* MERGEFORMAT Conclusions: The results of this study showed that the addition of pull or plyometric training to an Olympic weightlifting program interfered with weightlifting performances.

Agreement between the Open Barbell and Tendo Linear Position Transducers for Monitoring Barbell Velocity during Resistance Exercise.

To determine the agreement between the Open Barbell (OB) and Tendo weightlifting analyzer (TWA) for measuring barbell velocity, eleven men (19.4 ± 1.0 y) performed one set of 2–3 repetitions at four sub-maximal percentage loads, [i.e., 30, 50, 70, and 90% one-repetition maximum (1RM)] in the back (BS) and front squat (FS) exercises. During each repetition, peak and mean barbell velocity were recorded by OB and TWA devices, and the average of the 2–3 repetitions was used for analyses. Although the repeated measures analysis of variance revealed significantly (p ≤ 0.005) greater peak and mean velocity scores from OB across all intensities, high intraclass correlation coefficients (ICC2,K = 0.790–0.998), low standard error of measurement (SEM2,K = 0.040–0.119 m·s−1), and coefficients of variation (CV = 2–4%) suggested consistency between devices. Positive (r = 0.491–0.949) Pearson correlations between averages and differences (between devices) in peak velocity, as well as associated Bland-Altman plots, showed greater differences occurred as the velocity increased, particularly at low-moderate intensity loads. OB consistently provides greater barbell velocity scores compared to TWA, and the differences between devices were more apparent as the peak velocity increased with low-to-moderate loads. Strength coaches and athletes may find better agreement between devices if the mean velocity scores are only considered.

Caffeinated Gel Ingestion Enhances Jump Performance, Muscle Strength, and Power in Trained Men.

We aimed to explore the effects of caffeinated gel ingestion on neuromuscular performance in resistance-trained men. The participants (n = 17; mean ± standard deviation (SD): age 23 ± 2 years, height 183 ± 5 cm, body mass 83 ± 11 kg) completed two testing conditions that involved ingesting a caffeinated gel (300 mg of caffeine) or placebo. The testing outcomes included: (1) vertical jump height in the squat jump (SJ) and countermovement jump (CMJ); (2) knee extension and flexion peak torque and average power at angular velocities of 60°·s−1 and 180°·s−1; (3) barbell velocity in the bench press with loads corresponding to 50%, 75%, and 90% of one-repetition maximum (1RM); and (4) peak power output in a test on a rowing ergometer. Compared to the placebo, caffeine improved: (1) SJ (p = 0.039; Cohen’s d effect size (d) = 0.18; +2.9%) and CMJ height (p = 0.011; d = 0.18; +3.3%); (2) peak torque and average power in the knee extensors at both angular velocities (d ranged from 0.21 to 0.37; percent change from +3.5% to +6.9%), peak torque (p = 0.034; d = 0.24; +4.6%), and average power (p = 0.015; d = 0.32; +6.7%) at 60°·s−1 in the knee flexors; (3) barbell velocity at 50% 1RM (p = 0.021; d = 0.33; +3.5%), 75% 1RM (p < 0.001; d = 0.42; +5.4%), and 90% 1RM (p < 0.001; d = 0.59, +12.0%). We conclude that the ingestion of caffeinated gels may acutely improve vertical jump performance, strength, and power in resistance-trained men.

Comparison of 2- and 3-Minute Inter-Repetition Rest Periods on Maximal Jerk Technique and Power Maintenance

ABSTRACTPurpose: The aim of this study was to examine the effect of 3- vs. 2-minute inter maximal-repetition rest period (IMRRP) on maintaining jerk technical efficiency and power production during two successive maximal repetitions of Clean & Jerk (C&J). Methods: In a randomized, within subject, repeated measures design, nine elite-weightlifters (age: 24.4 ± 3.6 years, body mass: 77.2 ± 7.1 kg, height 176.0 ± 6.4 cm and 1RM C&J: 170.0 ± 5.0 kg) performed 2-separate testing sessions using 2 (IMRRP-2) and 3 (IMRRP-3) -minute IMRRP, while barbell kinematics and kinetics and joint kinematics were recorded. Results: Statistical analysis showed that one minute longer IMRRP enhanced the maintenance of optimal jerk technique evidenced by reducing declines in peak vertical barbell displacement (2.74%; p = .03), peak barbell velocity (2.89%; p = .03), and peak knee (1.61%; p = .03) and hip extensions (1.59%; p = .03) during the drive phase of the jerk. Additionally, IMRRP-3 led to maintaining optimal lifting strategy by reducing the increase in horizontal displacement during the descending (3.85%; p = .04) and ascending (5.42%; p = .02) phases. Increasing IMRRP from 2min to 3min was also shown to enhance kinetic variables evidenced by prompting higher peak vGRF (2.01%; p = .04) and power (2.55%; p = .04). Conclusion: To better identify an athlete’s maximal jerk technique and power maintenance, the results of this study suggest 3min as more appropriate IMRRP during successive C&J at 100% 1RM.

Effects of 7-Week Hip Thrust Versus Back Squat Resistance Training on Performance in Adolescent Female Soccer Players.

Hip thrust (HT) is a loaded bridging exercise that requires more hip extension than a back squat (SQ) does, while in a back squat, triple flex extension occurs. Due to the specificity of each exercise, it is claimed that HT gains can be better transferred to actions where hip extension occurs. In addition, strength improvements during squatting can be transferred in a greater way to vertical plane movement, such as vertical jumping. However, its effects on the performance of female soccer players are unclear. For this reason, the purpose of this study was to analyze a 7-week training program on performance variables using either HT or SQ exercises in female adolescent soccer players without lifting experience (N = 24, age = 16.82 ± 1.56 years, height = 1.64 ± 0.55 cm, body mass = 58.35 ± 6.28 kg). Players were randomized into three groups: A back squat group (SQG; N = 8), hip thrust group (HTG; N = 8), and control group (CG; N = 8). Participants in the HTG and SQG joined a progressive resistance training program twice per week for 7 weeks with either HT or SQ exercises. A countermovement jump, 10–20 m sprint, T-test, and barbell velocity during HTs and SQs (with the load that represents ~60 and ~80% RM) were measured before and after the intervention. The HTG showed greater improvements in the 10-m sprint (d = 0.7), 20-m sprint (d = 0.46), T-test (d = 0.36), and barbell velocity at 80% repetition maximal (RM) (d = 0.53) and 60% RM (d = 1.02) during hip thrusts, while the SQG showed higher barbell velocity at 80% RM (d = −0.7) during back squats. These results may be useful for strength and conditioning coaches working with adolescent female soccer athletes, since both strengthening exercises improved performance in different ways due to the nature of the exercise.