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Importance of the Propulsive Phase in Strength Assessment
Abstract
This study analyzed the contribution of the propulsive and braking phases among different percentages of the one-repetition maximum (1RM) in the concentric bench press exercise. One hundred strength-trained men performed a test with increasing loads up to the 1RM for the individual determination of the load-power relationship. The relative load that maximized the mechanical power output (P(max)) was determined using three different parameters: mean concentric power (MP), mean power of the propulsive phase (MPP) and peak power (PP). The load at which the braking phase no longer existed was 76.1+/-7.4% 1RM. P(max) was dependent on the parameter used: MP (54.2%), MPP (36.5%) or PP (37.4%). No significant differences were found for loads between 40-65% 1RM (MP) or 20-55% 1RM (MPP and PP), nor between P(max) (% 1RM) when using MPP or PP. P(max) was independent of relative strength, although certain tendency towards slightly lower loads was detected for the strongest subjects. These results highlight the importance of considering the contribution of the propulsive and braking phases in isoinertial strength and power assessments. Referring the mean mechanical values to the propulsive phase avoids underestimating an individual's true neuromuscular potential when lifting light and medium loads.
... After this insightful statement, followed by a series of pilot experiments, González-Badillo conducted several studies on movement velocity, with a particular focus on its application as a measure of loading intensity during resistance training sessions. [2][3][4] Background and Rationale ...
... If such zones truly existed, the concept of VBT would be fundamentally flawed-a notion that can be consistently refuted given the robust body of evidence supporting VBT. [2][3][4]9,10,14 That said, why does the sport science community continue to debate the adaptations within the force-velocity spectrum induced by a given exercise performed at different velocity zones? Three main reasons may help explain this issue: ...
... As such, if any variable (ie, movement velocity or relative load) can be independently modified within the close load-velocity relationship, it is highly probable that this would occur only in zones of extremely high velocity. The issue here lies in the limitation of measuring the actual velocity of these movements as most VBT studies are conducted using linear velocity transducers or linear position transducers, 3,4,15,22,24 which are considered the gold-standard devices for assessing bar velocity. Given that these devices require the exercises to be performed perfectly perpendicular to the ground for accurate measurements, the vast majority of VBT studies employ guided barbells (eg, Smith machines) for data collection. ...
Purpose : “If we could measure the velocity of movements daily and obtain immediate feedback, this would possibly be the best marker to determine whether the loading intensity is appropriate.” With this visionary statement made approximately 35 years ago, Juan José González-Badillo laid the foundation for what is now recognized as “velocity-based training” (VBT). VBT is based on the strong correlation between relative load and movement velocity (ie, the “load–velocity relationship”). The load–velocity relationship—the core concept behind VBT—demonstrates, through its high degree of shared variance ( R ² ≥ 95%), that it is impossible to manipulate one variable without directly impacting the other (eg, moving heavier relative loads at higher velocities). Nevertheless, a controversial point in the literature challenges this fundamental principle, introducing the subjective theory of “velocity-training zones.” The purpose of this commentary is to address this issue by reaffirming the elementary principle of VBT: Due to mechanical constraints, establishing distinct velocity zones is unfeasible and unrealistic. Conclusion : The primary objective of any resistance-training program is to increase force application against a given absolute load. Consistent with the near-perfect load–velocity relationship, this positive effect will undoubtedly enhance force production at both portions of the force–velocity spectrum (light-load/high-velocity and heavy-load/low-velocity portions). The rationale and logic supporting this argument are extensively detailed and discussed throughout this article.
... To the best of authors´knowledge, no prior studies have described these four phases. But, similarly, the present findings from phases 3 and 4 align with other studies that differentiate between the propulsive phase and the braking phase [46,47]. In the current work, after characterising the technical movement, it has been demonstrated that the concentric phase does not encompass the entire lifting motion (rise of the barbell). ...
... In line with current study findings, Pérez-Castilla et al. [56] determined that two different subphases can be identified within the concentric phase, referred to as the propulsive and braking phases, respectively. The propulsive phase is defined as the portion of the concentric phase in which the acceleration of the barbell exceeds the acceleration of gravity (≥−9.81 m·s −2 ), while the braking phase occurs when the force applied is lower than the barbell´s weight [46]. ...
... Additionally, the distribution of load intensity intervals is relatively broad. Although participants were instructed to push the barbell as fast as possible during each trial, this may have influenced the acceleration profile of the barbell, potentially deviating from the optimal acceleration curve principle [46]. Future research should consider defining the intensity intervals in advance and selecting narrower ranges of load intensity to achieve more precise results. ...
This study aimed (1) to explore the spatio-temporal phases of the execution of the bench press (BP) exercise based on barbell acceleration and power; (2) to describe barbell velocity, acceleration, mechanical power, and mechanical work at different load intensities; and (3) to analyse differences in kinematic and mechanical parameters. Twenty-one men (21.4 ± 1.5 years; 175.1 ± 6.7 cm; 75.8 ± 7.7 kg; 1RM: 91.7 ± 13.7 kg) and nine women (21.7 ± 2.3 years; 163.3 ± 10.8 cm; 57.2 ± 6.8 kg; 1RM: 38.9 ± 10.5 kg) were evaluated during the eccentric and concentric phases of the BP at different load intervals: interval 1 (55 to 75% 1RM), interval 2 (>75 to 85% 1RM) and interval 3 (>85 to 100% 1RM). Both temporal (duration) and mechanical variables (velocity, acceleration, mechanical power and mechanical work of the barbell) were determined using the Xsens MVN Link System. Mechanical variables were compared among the three different intervals. Interval 3 displayed greater duration compared to intervals 1 and 2. Barbell acceleration and power showed four different phases of BP movement, corresponding to the second and third phases of the exercise, bar braking (eccentric) and bar acceleration (concentric), respectively; the first and fourth phases are mainly determined by gravity instead of muscle intervention. Velocity and acceleration were different among the three different intervals during both the eccentric and concentric phases (p < 0.05). No differences were found between intervals 2 and 3 in mechanical power or mechanical work during the eccentric phase. In conclusion, the BP exercise has four phases considering barbell acceleration and power. The maximum and mean velocity and acceleration during BP performance decrease as load intensity increases. Maximum and mean mechanical power, and mechanical work, decrease progressively in the second and third intervals for both the eccentric and concentric phases. Thus, kinematics and mechanical parameters vary depending on load intensities.
... The wires of the devices (TF, VT1 and VT2) were located almost together (two centimeters of separation) on the right distal border of the bar in order to be in homogenous conditions. Two velocity outcome measures were obtained from each device in each repetition, which are the following: MPV [27] and peak of velocity (PV). For the subsequent analysis, the fastest repetition obtained with each absolute load (kg) was taken according to the criterion of the highest MPV [5,27]. ...
... Two velocity outcome measures were obtained from each device in each repetition, which are the following: MPV [27] and peak of velocity (PV). For the subsequent analysis, the fastest repetition obtained with each absolute load (kg) was taken according to the criterion of the highest MPV [5,27]. ...
... Recording a smaller number of data per second (specifically 10 times less) could significantly influence the following: (1) the maximum velocity value recorded (i.e., the PV) due to a smoothing of the velocity-time curve, and (2) the detection point of the start and end of the concentric phase of the movement, conditioning the duration of this phase and, consequently, the MPV calculated by LPT systems. For these reasons, the MPV has been defended as a reference for the determination and monitoring of relative load during VBRT [27]. ...
This study aimed to analyze the intra-device agreement of a new linear position transducer (Vitruve, VT) and the inter-device agreement with a previously validated linear velocity transducer (T-Force System, TF) in different range of velocities. A group of 50 healthy, physically active men performed a progressive loading test during a bench press (BP) and full-squat (SQ) exercise with a simultaneous recording of two VT and one TF devices. The mean propulsive velocity (MPV) and peak of velocity (PV) were recorded for subsequent analysis. A set of statistics was used to determine the degree of agreement (Intraclass correlation coefficient [ICC], Lin’s concordance correlation coefficient [CCC], mean square deviation [MSD], and variance of the difference between measurements [VMD]) and the error magnitude (standard error of measurement [SEM], smallest detectable change [SDC], and maximum errors [ME]) between devices. The established velocity ranges were as follows: >1.20 m·s⁻¹; 1.20–0.95 m·s⁻¹; 0.95–0.70 m·s⁻¹; 0.70–0.45 m·s⁻¹; ≤0.45 m·s⁻¹ for BP; and >1.50 m·s⁻¹; 1.50–1.25 m·s⁻¹; 1.25–1.00 m·s⁻¹; 1.00–0.75 m·s⁻¹; and ≤0.75 m·s⁻¹ for SQ. For the MPV, the VT system showed high intra- and inter-device agreement and moderate error magnitude with pooled data in both exercises. However, the level of agreement decreased (ICC: 0.790–0.996; CCC: 0.663–0.992) and the error increased (ME: 2.8–13.4% 1RM; SEM: 0.035–0.01 m·s⁻¹) as the velocity range increased. For the PV, the magnitude of error was very high in both exercises. In conclusion, our results suggest that the VT system should only be used at MPVs below 0.45 m·s⁻¹ for BP and 0.75 m·s⁻¹ for SQ in order to obtain an accurate and reliable measurement, preferably using the MPV variable instead of the PV. Therefore, it appears that the VT system may not be appropriate for objectively monitoring resistance training and assessing strength performance along the entire spectrum of load-velocity curve.
... However, variable resistance training (VRT) methods have gained popularity due to evidence suggesting that constant loads may not provide optimal resistance throughout the entire range of motion [2]. Studies have shown that the barbell decelerates in the final portion of the concentric phase, and the force production in the bench press is lower in the "sticking region" and the final portion of the movement [3,4]. ...
... To measure the mean propulsive velocity (MPV) and power (POW), a linear encoder from the Speed4Lift measurement system (Vitruve, Madrid, Spain) [24] was used to quantify the vertical displacement velocity, connected to the bench press bar. These parameters were analyzed before, immediately after, 24 h after and 48 h after the training session using a load of 45% of 1RM, where the velocity was expected to be approximately 1.0 m·s −1 [4]. The velocity data for the concentric phase were considered to begin at the ascending component of the movement and terminate at full elbow extension. ...
... a linear encoder from the Speed4Lift measurement system (Vitruve, Madrid, Spain) [24] was used to quantify the vertical displacement velocity, connected to the bench press bar. These parameters were analyzed before, immediately after, 24 h after and 48 h after the training session using a load of 45% of 1RM, where the velocity was expected to be approximately 1.0 m·s −1 [4]. The velocity data for the concentric phase were considered to begin at the ascending component of the movement and terminate at full elbow extension. ...
Variable resistance training has been widely used in athletic preparation. Objectives: To analyze the use of currents (VRT) and the traditional method (TRAD) on speed, power and temperature in a training session. Methods: Fourteen paralympic powerlifting (PP) athletes took part over three weeks. In week 1, familiarization and 1RM tests took place, and, in weeks 2 and 3, pre- and post-training took place, where the propulsive mean velocity and power and temperatures were assessed before and after, at 24 h and 48 h. Results: There was a difference in the sternal pectoral temperatures before and after VRT (p = 0.040) and at 48 h for TRAD and VRT (p = 0.018); in the clavicular pectoralis before and after VRT and TRAD (p = 0.003); in the anterior deltoid after and at 48 h for TRAD and VRT (p = 0.026 and p = 0.017); and in the triceps after and at 24 h and 48 h between TRAD and VRT (p = 0.005). In the training series, the MPV was significant in TRAD between Set1 and Set5 (p = 0.003), in training (VRT) between Set1 and Set5 (p = 0.001) and in Set5 between the methods (p = 0.047). For power, there was a difference between Set1 and 5 in TRAD (p = 0.016) and VRT (p = 0.002). Conclusion: We conclude that training with currents (VRT) promoted greater muscle fatigue when compared to traditional training.
... Regarding velocity variables to assess and monitor strength performance, research indicates that the mean propulsive velocity (MPV) is critical when programming and monitoring resistance training [7]. The MPV only considers the propulsive phase of the lift (i.e., the portion of the concentric phase in which the barbell acceleration is higher than gravity) and avoids underestimating the strength potential when lifting low and moderate relative loads with maximal intended velocities [7,8]. ...
... Regarding velocity variables to assess and monitor strength performance, research indicates that the mean propulsive velocity (MPV) is critical when programming and monitoring resistance training [7]. The MPV only considers the propulsive phase of the lift (i.e., the portion of the concentric phase in which the barbell acceleration is higher than gravity) and avoids underestimating the strength potential when lifting low and moderate relative loads with maximal intended velocities [7,8]. Alongside the MPV, the peak velocity (PV) and time to peak velocity (TPV) assume great relevance in monitoring and testing sport-specific movements performed with maximal intended velocities, such as throws, sprints, and jumps [9][10][11][12][13]. ...
... In the first session, we measured each subject's height and body mass (Seca Instruments, Ltd., Hamburg, Germany) and gave instructions regarding the specific execution techniques in the bench press and squat following procedures described elsewhere [7,19]. We also identified the correct position for each subject, which was then used during testing and training protocols. ...
We analyzed the influence of exercise order using the bench press and squat as the first or second exercise of the session on velocity performance. Ten male trained individuals (20.9 ± 0.7 years) randomly performed two protocols of three sets of six repetitions at 80% of their one-repetition maximum with different exercise sequences: the bench press followed by the squat (BP + S) and the squat followed by the bench press (S + BP). A linear velocity transducer attached to the Smith machine barbell measured the mean propulsive velocity (MPV), peak velocity (PV), and time to peak velocity. Additionally, blood lactate and heart rate were measured. Regarding the bench press, differences were found in the MPV in the first (BP + S: 0.50 ± 0.07 m·s⁻¹ vs. S + BP: 0.42 ± 0.08 m·s⁻¹; p = 0.03, g = 0.72) and second sets (0.50 ± 0.06 m·s⁻¹ vs. 0.42 ± 0.07 m·s⁻¹; p = 0.03, g = 0.73), and in the PV in the second set (0.74 ± 0.09 m·s⁻¹ vs. 0.63 ± 0.09 m·s⁻¹; p = 0.02, g = 0.86). Regarding the squat, although the S + BP sequence tended to show higher velocities, no significant differences were found between protocols. These results showed that squatting first decreased subsequent bench press velocity performance. On the other hand, squat velocity performance was not impaired when preceded by the bench press.
... In addition, during the test, the participants received verbal motivation from the research team [33]. A Chrono Jump ® linear encoder and the Chrono Jump version 1.4.6.0 ® software (Barcelona, Spain) were used to evaluate the 1RM in HBSs [34]. During the evaluation of the 1RM, the progression of the loads (kg) and the corresponding execution velocities were recorded (m/s). ...
... All the partici were asked to lift the weight vertically as fast as possible for each load. In addition, d the test, the participants received verbal encouragement from the research team [3 Chrono Jump ® linear encoder and the Chrono Jump version 1.4.6.0 ® software (Barce Spain) were used to evaluate the three HBS sets [34]. In the statistical analysis, the velocity (m/s) and the mean power (W) were the variables used to quantify the differe isolated and summative, in creatine and caffeine supplementation and pre-activation I-sVR. ...
... In addition, during the test, the participants received verbal encouragement from the research team [33]. A Chrono Jump ® linear encoder and the Chrono Jump version 1.4.6.0 ® software (Barcelona, Spain) were used to evaluate the three HBS sets [34]. In the statistical analysis, the mean velocity (m/s) and the mean power (W) were the variables used to quantify the differences, isolated and summative, in creatine and caffeine supplementation and pre-activation with I-sVR. ...
There is evidence that both intra-serial variable resistance (I-sVR), as pre-activation within the post-activation performance enhancement cycle (PAPE), and creatine and caffeine supplementation increase athletic performance in isolation. However, the effect of the three conditioning factors on 30 m repeated sprint ability (RSA) performance in young soccer players is unknown. This study determined the summative and isolation effect of ergogenic aids and pre-activation in half-back squats (HBSs) with I-sVR on performance in an RSA test in young soccer players. Twenty-eight young soccer players were randomly assigned to either EG1 (n = 7, creatine + caffeine + I-sVR), EG2 (n = 7, creatine + placebo2 + I-sVR), EG3 (n = 7, placebo1 + caffeine + I-sVR), or EG4 (n = 7, placebo1 + placebo2 + I-sVR), using a factorial, four-group-matched, double-blind, placebo-controlled design. Creatine supplementation included 0.3 g/kg/day for 14 days, caffeine supplementation included 0.3 mg/kg per day, and pre-activation in HBS with I-sVR (1 × 5 at 30% 1RM [1.0–1.1 m/s] + 1 × 4 at 60% 1RM [0.6–0.7 m/s]). The RSA test and HBS outcomes were evaluated. Three-way ANOVA showed non-significant differences for the RSA test and HBS outcomes (p > 0.05). At the end of this study, it was found that the three ergogenic aids, together, do not generate a summative effect on the physical performance of young soccer players. However, it is important to analyze individual responses to these specific protocols.
... Two velocity variables were used for analyses: 1) mean propulsive velocity (MPV) and 2) peak velocity (PV). The MPV was defined as a mean velocity value of the portion of the concentric phase during which barbell acceleration was greater than the acceleration due to gravity [31]. The PV was established as the maximum instantaneous velocity value reached during the concentric phase [23]. ...
... These findings can be interpreted as a result of the greater sensitivity of the MPV to discriminate the fatigue level during the concentric phase of the movement. The concentric phase of the movement can be subdivided into two portions: 1) propulsive (F > 0) and braking (F < 0) [31]. The hip and knee extensor muscles work collectively to produce high levels of force to break inertia and accelerate the bar throughout the propulsive phase of the back-squat. ...
... The hip and knee extensor muscles work collectively to produce high levels of force to break inertia and accelerate the bar throughout the propulsive phase of the back-squat. During the concentric phase of the back-squat from a static position, the initial velocity of the movement is zero, achieves peak velocity at the final part of the propulsive portion of the lift, and returns to zero velocity at the end of braking [31]. The presence of neuromuscular fatigue impairs muscle contractile function and, consequently, the capacity of the neuromuscular system to produce force and velocity in the propulsive portion of the concentric phase [2]. ...
We analyzed the effects of load magnitude and bar velocity variables on sensitivity to fatigue. Seventeen resistance-trained men (age=25.7±4.9 years; height=177.0±7.2 cm; body mass=77.7±12.3 kg; back-squat 1RM=145.0±33.9 kg; 1RM/body mass=1.86) participated in the study. Pre- and post-exercise changes in the mean propulsive velocity (MPV) and peak velocity (PV) in the back-squat at different intensities were compared with variations in the countermovement jump (CMJ). CMJ height decreased significantly from pre- to post-exercise (∆%=-7.5 to -10.4; p<0.01; ES=0.37 to 0.60). Bar velocity (MPV and PV) decreased across all loads (∆%=-4.0 to -12.5; p<0.01; ES=0.32 to 0.66). The decrease in performance was similar between the CMJ, MPV (40% and 80% 1RM; p=1.00), and PV (80% 1RM; p=1.00). The magnitude of reduction in CMJ performance was greater than MPV (60% 1RM; p=0.05) and PV (40% and 60% 1RM; p<0.01) at the post-exercise moment. Low systematic bias and acceptable levels of agreement were only found between CMJ and MPV at 40% and 80% 1RM (bias=0.35 to 1.59; ICC=0.51 to 0.71; CV=5.1% to 8.5%). These findings suggest that the back-squat at 40% or 80% 1RM using MPV provides optimal sensitivity to monitor fatigue through changes in bar velocity.
... In this regard, the vast majority of the studies analyse the effects on similar absolute loads or, failing that, relative loads established with respect to the value of 1RM (Maté-Muñoz et al., 2018;Silva-Grigoletto et al., 2020;De-Oliveira et al., 2021;De-Oliveira et al., 2022), which can present serious limitations (Sanchez-Medina and González-Badillo, 2011;Elvar-Heredia et al., 2021;Maté-Muñoz et al., 2022). Thus, propulsive velocity has been identified as the most precise variable for evaluating the intensity of strength exercises (Sanchez-Medina et al., 2010;Sanchez-Medina and González-Badillo, 2011). Accordingly, athletes who attain higher mean propulsive velocity (MPV) at the same load exhibit lower relative intensity values. ...
... As shown in the introduction mean propulsive velocity (MPV) was considered as the most accurate variable to assess the intensity Frontiers in Physiology frontiersin.org of strength exercises (Sanchez-Medina et al., 2010). The results present in this research showed AMRAP as the modality with the lowest MPV values. ...
... This fact indicates that the athletes can self-regulate the intensity during the modality depending mainly on the characteristics, total duration, and rest periods. This could point out how these modalities cannot be considered as high-intensity modalities given that in high-intensity exercises, if the relative intensity in each exercise were very high, the ability to selfmanage the velocity throughout the repetitions would be very limited and conditioned (Sanchez-Medina et al., 2010;González-Badillo et al., 2017). This fact is in contrast with other research on the field (Feito et al., 2018;Feito et al., 2019) and the American College Sports Medicine (ACSM) annual survey in which CrossFit was indicated as the primary reason HIIT workouts (Thompson, 2013;2017). ...
Introduction: In recent years, a surge of interest in high-intensity training methods, associated with “cross” modalities has emerged as a promising approach for improving performance and overall health. Therefore, the main aim of this study was to compare the acute effects on heart rate, mean propulsive velocity and intra and inter-set velocity loss in “Cross” modalities.
Materials and methods: Twelve athletes, 10 men’s and 2 women’s (age: 31.5 ± 6.74 years; height: 174.17 ± 6.05 cm; weight: 75.34 ± 7.16 kg) with at least 1 year of experience in “cross” training. The participants performed three different “cross” modalities, Rounds for Time (RFT), Every Minute on the Minute (EMOM) and As Many Rounds As Possible (AMRAP) across three separate days. In each modality participants carried out 10 repetitions of squat, pull-ups, and shoulder press with difference rates of work-rest. Mean propulsive velocity (MPV) and heart rate (HR) were recorded and analysed for each athlete. Repeated measures one-way ANOVA and repeated measures two-way ANOVA were performed to analyse the differences between modalities and subjects. Besides, a Bonferroni post hoc analysis was carried out to assess the differences between modalities in each subject.
Results: Significant differences in MPV were observed among the modalities. The comparisons between RFT and AMRAP, as well as EMOM and AMRAP, revealed lower MPV in the AMRAP modality (p < 0.01). RFT exhibited the greatest intra-set velocity loss, while EMOM showed the least, with significant distinctions (p < 0.01) between them. Furthermore, significant differences in the HR results were noted among all modalities (p < 0.05).
Conclusion: Findings consistently identify the AMRAP modality as having the lowest MPV values due to its prolonged duration, promoting self-regulated tempo for optimal performance and technique, while the RFT modality exhibits higher fatigue and intra-set MPV losses. These insights into propulsive velocity, intensity, fatigue, and pacing across various “Cross” modalities provide valuable guidance for athletes and trainers seeking to enhance their exercise programs.
... Since athletes need to improve their performance through exercise, strength and conditioning coaches have focused on various techniques and training programs that can enhance athletic performance. One of the most common exercises is the bench press, which in turn helps athletes develop neuromuscular qualities and subsequently improve skills-related athletic performance (Sanchez-Medina et al., 2009). In this context, bench press throw is widely used to improve power-related capacities among athletes (Suchomel et al., 2018). ...
... The rest period was 3 min for lighter and medium loads, while it was 5 min for the heaviest loads. The rest period between the repetitions executed with the same load was also 10 s (Sanchez-Medina et al., 2009;Torrejón et al., 2019). ...
... Subjects performed the bench press throw in accordance with the method, which was extensively described in previous studies (Sanchez-Medina et al., 2009;Davies et al., 2018). The participants were first asked to execute the eccentric phase with control, holding a static position for at least one second at the end of this phase, ensuring that the bar lightly touched the chest. ...
Introduction: The objectives of the present study were twofold: first, to identify the specific relative load at which the concentric motion transforms into a purely propulsive action among women, and second, to compare the load-velocity relationships between men and women during the bench press throw.
Methods: Fourteen men and fourteen women participated in a test where they progressively increased the load until reaching their one-repetition maximum (1RM) in the bench press exercise. Linear regression models were employed to elucidate the relationships between load and velocity, as well as load and the propulsive phase (% of total concentric time). Additionally, ANCOVA was utilized to compare the linear regression models between men and women.
Results: The results revealed strong and linear associations between load and mean propulsive velocity (MPV) for both men and women, as well as between load and the propulsive phase. Notably, there were significant differences in MPV and the propulsive phase concerning load between men and women. Women transitioned into a fully propulsive concentric phase at approximately 80% of their 1RM, while men achieved this entirely propulsive phase at around 85% of their 1RM. Furthermore, women exhibited reduced velocities when handling lighter relative loads compared to men. Conversely, women demonstrated higher velocities when dealing with loads exceeding 85% of their 1RM in contrast to their male counterparts.
Discussion: These findings hold notable implications for prescribing bench press throw loads for women, which should differ from those recommended for men. Further studies are necessary to validate the efficacy of the proposed load recommendations.
... Twelve resistance-trained adult men (a range of [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] participated in this study (Table 1). Inclusion criteria were (a) adult men without limitations in BS exercise, (b) a proficient BS exercise technique, and (c) $ 1 year of BS training experience. ...
... The greatest PV and PP observed during AEL 1 RR 5 support our hypothesis because of more frequent potentiation and maintenance across 10 repetitions. Although the increase in PV and PP across all 10 repetitions seems to be highly unique and promising, coaches might need to be aware that such acute responses may not chronically improve lower-body power development (29). Given that PV and PP occur much later than a sticking region (i.e., at the end of the concentric "acceleration" phase), their practical relevance to power development might not be as great as MV and MP that represent the entire concentric phase (29). ...
... Although the increase in PV and PP across all 10 repetitions seems to be highly unique and promising, coaches might need to be aware that such acute responses may not chronically improve lower-body power development (29). Given that PV and PP occur much later than a sticking region (i.e., at the end of the concentric "acceleration" phase), their practical relevance to power development might not be as great as MV and MP that represent the entire concentric phase (29). Nevertheless, our data still provide a unique insight into the effect of 110/60% BS 1RM and the number of AEL repetitions on peak kinetic and kinematic responses where PV and PP can be elevated using AEL 1 RR 5 even with decreased PF. ...
Chae, S, Long, SA, Lis, RP, McDowell, KW, Wagle, JP, Carroll, KM, Mizuguchi, S, and Stone, MH. Combined accentuated eccentric loading and rest redistribution in high-volume back squat: Acute kinetics and kinematics. J Strength Cond Res 38(4): 640–647, 2024—The purpose of this study was to explore acute kinetic and kinematic responses to combined accentuated eccentric loading and rest redistribution (AEL + RR). Resistance-trained men (n = 12, 25.6 ± 4.4 years, 1.77 ± 0.06 m, and 81.7 ± 11.4 kg) completed a back squat (BS) 1 repetition maximum (1RM) and weight releaser familiarization session. Three BS exercise conditions (sets × repetitions × eccentric/concentric loading) consisted of (a) 3 × (5 × 2) × 110/60% (AEL + RR 5), (b) 3 × (2 × 5) × 110/60% (AEL + RR 2), and (c) 3 × 10 × 60/60% 1RM (traditional sets [TS]). Weight releasers (50% 1RM) were attached to every first repetition of each cluster set (every first, third, fifth, seventh, and ninth repetition in AEL + RR 5 and every first and sixth repetition in AEL + RR 2). The AEL + RR 5 resulted in significantly (p < 0.05) greater concentric peak velocity (PV) (1.18 ± 0.17 m·s−1) and peak power (PP) (2,304 ± 499 W) compared with AEL + RR 2 (1.11 ± 0.19 m·s−1 and 2,148 ± 512 W) and TS (1.10 ± 0.14 m·s−1 and 2,079 ± 388 W). Furthermore, AEL + RR 5 resulted in significantly greater PV and PP across all 10 repetitions compared with TS. Although AEL + RR 5 resulted in significantly greater concentric mean force (MF) (1,706 ± 224 N) compared with AEL + RR 2 (1,697 ± 209 N) and TS (1,685 ± 211 N), no condition by set or repetition interactions existed. In conclusion, AEL + RR 5 increases PV and PP but has little effect on MF. Coaches might consider prescribing AEL + RR 5 to increase especially peak aspects of velocity and power outcomes.
... A Smith-machine (Multipower Fitness Line, Peroga, Murcia, Spain) without a counterweight mechanism was used. Repetitions were recorded using a linear velocity transducer (T-Force System Ergotech, Murcia, Spain), which is valid and reliable [17]. The SQ was performed with participants starting from an upright position, with their knees and hips fully extended, feet parallel and about shoulder-width apart, and the barbell resting across the back at the acromion level. ...
... The fastest MPV achieved for each load was considered for further analysis. All reported velocities in this study correspond to the mean velocity of the propulsive phase of each repetition [17]. Moreover, MPVs were categorized into different portions of the load-velocity spectrum: (a) average MPV achieved against all absolute loads common to pre-and post-tests (AV); (b) average MPV achieved against absolute loads moving faster than 1 m·s −1 at pre-training (AV > 1, 'light' loads); and (c) average MPV achieved against absolute loads moving slower than 1 m·s −1 at pre-training (AV < 1, 'heavy' loads). ...
(1) Background: The range of loads is defined as the difference between the highest and the lowest relative load (i.e., %1RM) used throughout a resistance training program. However, the optimal range of loads has not been studied yet. Thus, the aim of this study was to compare the effects of different ranges of load (from 50 to 85% 1RM (R50–85), from 55 to 75% 1RM (R55–75), and from 60 to 70% 1RM (R60–70) on physical performance using velocity-based resistance training (VBT). (2) Methods: Thirty-eight men (mean ± standard deviation; age: 23.3 ± 3.6 years, body mass: 76.5 ± 8.3 kg, and height: 1.77 ± 0.04 m) were randomly assigned to R50–85, R55–75 and R60–70 groups and followed an 8-week VBT intervention using the full squat (SQ) exercise. All groups trained with similar mean relative intensity (65% 1RM) and total volume (240 repetitions). Pre- and post-training measurements included the following: in the SQ exercise, 1RM load, the average velocity attained for all absolute loads common to pre-tests and post-tests (AV), and the average velocity for those loads that were moved faster (AV > 1) and slower (AV < 1) than 1 m·s−1 at Pre-training tests. Moreover, countermovement jump (CMJ) height and 10 m (T10), 20 m (T20), and 10–20 m (T10–20) running sprint times were measured. (3) Results: Significant group x time interactions were observed in AV (p ≤ 0.01), where R50–85 obtained significantly greater gains than R60–70 (p ≤ 0.05). All groups attained significant increases in 1RM, AV, AV > 1, AV < 1, and CMJ (p ≤ 0.001–0.005). Significant improvements were observed in running sprint for R60–70 in T10–20 and R60–70 in T20 and T10–20 (p ≤ 0.05), but not for R50–85. (4) Conclusions: Different ranges of loads induce distinct strength adaptions. Greater ranges of loads resulted in greater strength gains in the entire load-velocity spectrum. However, in high-velocity actions, such as sprinting, significant enhancements were observed only for smaller ranges of loads. Coaches and strength and conditioning professionals could use a range of loads according to the time-related criterion (i.e., proximity or number of future competitions), enabling better adaptation and increasing physical performance at a specific time.
... A randomized repeated measures study was conducted to examine the test-retest reliability of three LPT-Cs using a simultaneous triangulation method of the same device in bench press (BP) and back squat (SQ) exercises performed on a Smith machine. The LPT-Cs, spaced 5 cm apart, measured and collected ∆S and MPV, which was understood as the fraction of the concentric phase during which the measured acceleration was greater than the acceleration due to gravity [29]. PV was considered the highest instantaneous value of bar velocity during the concentric phase, and T-PV provided by the three devices. ...
... It is important to highlight that MPV was the variable used since, for more than 80% of the participants, the standardized weight (men: BP ≥ 40 kg and SQ ≥ 60 kg; women: BP ≥ 30 kg and SQ ≥ 40 kg) represented between 40% and 70% of their RM. Therefore, we had to follow previous recommendations [29]. As expected, our data responded to variability patterns, likely because the recruited subjects were from a university population. ...
Citation: Montoro-Bombú, R.; Costa, A.; Sousa, P.M.; Pinheiro, V.; Forte, P.; Monteiro, L.; Ribeiro, A.S.; Rama, L. Reliability and Accuracy of Linear Position Transducers During the Bench Press and Back Squat: Implications for Velocity-Based Training. Abstract: Background: Selecting the right linear position transducer (LPT) for velocity-based training monitoring sometimes presents uncertainties for coaches. Objectives: This study rigorously examined the test-retest reliability of three LPT-Cs using a simultaneous triangulation method of the same device during bench press (BP) and back squat (SQ) exercises performed on a Smith machine. Methods: Forty university students-13 females (23 ± 2 years) and 27 males (31.5 ± 6 years)-voluntarily participated in a randomized repeated-measures study. LPTs were randomly assigned numbers and placed at 5 cm apart to measure and collect bar displacement (∆S), mean propulsive velocity (MPV), peak velocity (PV), and time to peak velocity (T-PV). Each volunteer performed three BP and SQ attempts with pre-standardized loads (males: BP ≥ 40 kg and SQ ≥ 60 kg; females: BP ≥ 25 kg and SQ ≥ 40 kg). Results: The main findings of this study support a high degree of reliability for LPTs. For all variables, the absolute reliability presented significant values (p ≤ 0.05), with an intraclass correlation coefficient ≥ 0.995, a 95% confidence interval between 0.992-0.999, a coefficient of variation ≤ 10%, and a standard error of the mean ≤ 0.031. Conclusions: Scientists and coaches can use the LPT device as a reliable tool for monitoring velocity-based training by providing rigorous measurements of ∆S, MPV, PV, and T-PV during BP and SQ exercises. In addition, the smallest real difference reported may be useful in identifying minimal changes in ∆S within a single set (BP = 0.10 cm; SQ = 0.13 cm).
... Other parameters such as mean propulsive velocity (MPV) (18,25) and concentric peak power (4,29) have been suggested, although similar peak power values can be achieved at various RID moments of inertia (force typically increases at greater resistances, velocity typically decreases at great resistances, and power is force multiplied by velocity) (12). In addition, peak power refers only to a single time point during the movement, while MPV takes into account the entire concentric action and is the most commonly used parameter for monitoring the TRT intensity in real time when using RID (13,24). Furthermore, the fatigue and variability between repetitions can also affect comparisons. ...
... Despite the similar shape, RID exhibited a lower development of vGRF than TRT throughout the concentric phase, except in the final segment (70-95%), where RID achieved higher vGRF values. When squatting with a load lighter than 80% of the 1RM, the athlete does not apply force throughout the whole range of concentric movement (24). On the other hand, research suggests that RIDs enable maximal muscle activation throughout the full range of motion (16). ...
Although rotary inertial devices (RIDs) have been used in resistance training for many years, there is still limited knowledge of the specific biomechanics that distinguish them from traditional resistance training (TRT) methods. The aim of this study is to
compare the serial data of force, velocity, and displacement over time in half-squats performed with both devices when the intensity is based on the concentric mean propulsive velocity (MPV). A total of 20 experienced subjects completed 3 sets of 6 half-squats using both RID and TRT. To ensure a similar load intensity, the concentric phase was matched according to the MPV. Measurements of vertical ground reaction force (vGRF), velocity, and displacement were taken for each repetition of the half-squat. The results showed that TRT exhibited a higher vGRF than RID during 0–57% of the concentric phase but a lower vGRF during 74–93% (p,0.001). Eccentric vGRF was also higher for TRT throughout much of the eccentric phase (0–13%, 38–54%, and 68–100%, p, 0.001). Rotary inertial device demonstrated faster vertical velocity than TRT during 31–52% of the concentric phase and 1–40% of the eccentric phase (p , 0.001). However, during the latter part of the concentric phase (72–99%), TRT exhibited faster vertical velocity compared with RID. In addition, TRT resulted in a higher vertical position than RID at the end (67–100%) of the concentric phase (p 5 0.036). Coaches should be aware of these biomechanical differences when prescribing resistance training with RID or TRT, as even with similar loads, distinct patterns in vGRF and velocity over time can lead to different effects on the athlete.
... To motivate participants to exert maximum effort, they received strong verbal encouragement and feedback on speed during each repetition. The initial load was set at 20kg for men and 10kg for women and increased in 10 kg increments until velocity was 0.60ms-1(Sanchez-Medina et al., 2010); after that, the load was increased in 2.5-5 kg increments so that the 1RM could be accurately determined. Only the best repetition at each load was considered for subsequent analysis(Sanchez-Medina et al., 2010). ...
... The initial load was set at 20kg for men and 10kg for women and increased in 10 kg increments until velocity was 0.60ms-1(Sanchez-Medina et al., 2010); after that, the load was increased in 2.5-5 kg increments so that the 1RM could be accurately determined. Only the best repetition at each load was considered for subsequent analysis(Sanchez-Medina et al., 2010). Three repetitions were performed for light (50% 1RM), two for medium (50-80% 1RM), and only one for the heaviest loads (>80% 1RM). ...
Post-activation performance enhancement (PAPE) refers to the temporary improvement in physical abilities resulting from a previous conditioning activity (CA), and velocity-based resistance training has been proposed to optimise PAPE. The present study aimed to evaluate the optimal rest interval to induce PAPE in the countermovement jump using heavy parallel squats monitored by the velocity loss (VL) threshold. The study had a randomised repeated measures design, with three sessions that included a control session and two different squat conditions (80% of 1 repetition maximum (RM) with 10% and 30% VL of mean propulsive velocity). Ten men (age 21.91.16 years, height 1.80.04m, body weight 78.59.9kg, relative strength: 1.40.29kgkg-1) and ten women (age 20.71.16 years, height 1.60.06m, body weight 56.94.67kg, relative strength: 1.10.19kgkg-1) participated in the study. They had at least 1 year of experience with the back squat but no experience in power training. Measurements were taken at baseline and at six time points after the conditioning activity or rest period. The study found no significant effects between intervention and moment and no optimal rest time to induce PAPE, but women had significantly lower countermovement jump (CMJ) values than men(Mmen = 30.01, SE = 1.35; 95% CI 27.17-32.84, Mwomen = 24.33, SE = 1.35, 95% CI = 21.50-27.16), but when values were normalised to body weight, there were no significant differences. In conclusion, a single set of 80% 1RM in the squat to a VL of 10% or 30% is not sufficient to induce PAPE in CMJ; therefore, there is no optimal rest time.
... For instance, mean propulsive velocity (MPV) and peak velocity (PV) measurements can be useful for estimating fatigue across sets [2][3][4]. Additionally, MPV provides valuable information for optimizing athletes' training programs [1,5]. Thus, the identification of a portable and cost-effective device (e.g., Vitruve) capable of precise measurements is crucial to fully utilize this information under field conditions. ...
... Therefore, the practical application might be more transferable to real training, where the users obtain PV or MPV directly from the display of these devices. The MPV has been advocated as a benchmark for determining and monitoring velocity-based strength training [5,16], for the reasons mentioned in the previous paragraph. ...
This study evaluated the concurrent validity of the Vitruve linear encoder compared to the T-Force device for measuring mean propulsive velocity (MPV) and peak velocity (PV) during the free-weight bench press exercise. Thirteen resistance-trained men participated in three sessions, during which MPV and PV were recorded simultaneously by both devices. The data were analysed using one-way ANOVA, Pearson’s correlation, Bland–Altman analysis, and effect size calculations, with statistical significance set at p ≤ 0.05. The results showed discrepancies between the Vitruve and T-Force devices across different intensity levels. Specifically, the Vitruve device generally reported higher MPV and lower PV values, particularly at moderate and low intensities. Vitruve was deemed useful for MPV measurements, especially at velocities below 0.65 m/s during free-weight bench press exercises. In conclusion, the Vitruve device overestimated MPV and underestimated PV at moderate and low loads (>0.65 m·s⁻¹), with the discrepancies increasing as velocity rose. It can provide valuable data for monitoring and assessing resistance training programs focused on MPV at heavier loads (<0.65 m·s⁻¹). Researchers and practitioners should take these findings into account when incorporating the Vitruve into velocity-based strength training protocols.
... For instance, measuring means propulsive velocity (MPV) and peak velocity (PV) may be useful for estimating fatigue over series [2][3][4]. Additionally, MPV can offer valuable insights for athletes in training programs [1,5]. However, identifying a reliable device capable of accurately measuring it is essential to fully leverage this information. ...
... Therefore, the practical application might be more transferable to real training, where the users obtain PV or MPV directly from the display of these devices. The MPV has been advocated as a benchmark for determining and monitoring the velocity-based strength training [5,16], for the reasons mentioned in the previous paragraph. ...
This study evaluated the concurrent validity of the Vitruve linear encoder compared to the T-Force device for measuring mean propulsive velocity (MPV) and peak velocity (PV) during the free-weight bench exercise. Twelve resistance-trained men participated in three sessions, during which MPV and PV were recorded sim-ultaneously by both devices. The data were analyzed using one-way ANOVA, Pearson's correlation, Bland-Altman analysis, and effect size calculations, with statistical significance set at p ≤ 0.05. The results showed discrepancies between the Vitruve and T-Force devices across different intensity levels. Specifically, the Vitruve device generally reported higher MPV and lower PV values, particularly at moderate and low in-tensities. Vitruve was deemed useful for MPV measurements, especially at velocities below 0.65 m/s during free-weight bench press exercises. In conclusion, the Vitruve device overestimated MPV and underestimated PV at moderate and low loads (> 0.65 m·s⁻¹), with the discrepancies increasing as velocity rose. It can provide valuable data for monitoring and assessing resistance training programs focused on MPV at heavier loads (< 0.65 m·s⁻¹). Researchers and practitioners should take these findings into account when incorporating the Vi-truve into velocity-based strength training protocols.
... To compare the six different measuring tools, a within subject design was used in which all measuring tools were attached while performing the squat and bench press exercises at different intensities. Mean propulsive [17], mean, and peak velocities were the dependent variables tested across five different loads, and they were used to investigate the impact of load and exercise type on the outcome measures together with 1-RM load testing. Participants completed two repetitions at each load at low loads (≤65% of 1-RM) and one repetition at higher loads. ...
... The mean propulsive and peak velocity of each repetition recorded by Speed4lifts was later exported for analysis. Mean velocity is the average velocity of the entire upward phase of the lift, while mean propulsive velocity is the average velocity during the propulsive phase, defined as the portion of the upward phase where acceleration is greater than gravity [17]. ...
The aim of this study was to compare barbell velocities at different intensities and estimated 1-RM with actual 1-RM measured with different measuring tools in bench presses and squats. Fourteen resistance-trained athletes (eight men, six women, age 28.1 ± 7.5 years, body mass 78.1 ± 12.2 kg, body height 1.73 ± 0.09 m) performed bench presses and squats at five loads varying from 45 to 85% of one repetition maximum (1-RM), together with 1-RM testing, while measuring mean, mean propulsive, and peak barbell velocity with six different commercially used inertial measurement units (IMUs) and linear encoder software systems attached to the barbell. The 1-RM was also estimated based upon the load–velocity regression, which was compared with the actual 1-RM in the bench press and squat exercises. The main findings were that GymAware revealed the highest reliability along with minimal bias, while Musclelab and Vmaxpro showed moderate reliability with some variability at higher loads. Speed4lifts and PUSH band indicated greater variability, specifically at higher intensities. Furthermore, in relation to the second aim of the study, significant discrepancies were found between actual and estimated 1-RM values, with Speed4lifts and Musclelab notably underestimating 1-RM. These findings underscore the importance of selecting reliable tools for accurate velocity-based training and load prescription.
... Before beginning the 1-RM test (32,38,41,42), subjects performed the following standardized warmup: 5 min of rowing on a rowing ergometer followed by cat-cow flow, thoracic rotations, dynamic down dogs, and pushups (8-10 repetitions each). After the standardized warm-up, subjects were permitted 3-5 min to perform any exercise that they would typically do before a bench press training session. ...
... For each repetition, subjects were instructed to grip the barbell as they would during their usual training sessions and to maintain 5 points of body contact throughout: head, upper back, and buttocks on the bench with both feet planted firmly on the floor (43). Lifters controlled the eccentric phase of motion, paused for ~1 s with the barbell on their chest, and performed the concentric phase of motion as fast as possible following a "go" command from a researcher (41,42). Velocity was monitored with the linear velocity transducer (Power Analyzer V-620, TENDO Sports Machines, London, UK) that was fixed to the right side of the barbell via a velcro strap. ...
This study analyzed the effect of ascending pyramid (AP), constant load (CL), and descending pyramid (DP) training on repetition performance, training volume, barbell velocity, mechanical fatigue, and perceptual measurements during bench press exercise. Eighteen well-trained young males (18-40 years) performed AP, CL, and DP in a randomized order. Subjects were ranked according to relative strength ratio (Bench press 1-RM ÷ body mass) and the total sample of 18 males was divided into two groups: group 1 (G1), n = 9, RSR = 1.20-1.56; group 2 (G2), n = 9, RSR = 0.75-1.16. Volume (5 sets), relative intensity (65-85% 1-RM), set end point (25% velocity loss (VL)), and rest intervals (5 min) were matched between conditions. Relative intensity did not change during CL (75% 1-RM), while sets were performed from light-to-heavy during AP (65-70-75-80-85% 1-RM), and heavy-to-light during DP (85-80-75-70-65% 1-RM). Repetition performance, total volume load (TVL), mean and peak velocity, VL, and ratings of perceived exertion (set-RPE) were measured during each session while affect, discomfort, enjoyment, and session-RPE were measured after each session. Mean and peak velocity with 45% 1-RM were assessed before, 5-min after, and 10-min after each session. Data indicated that peak velocity and set-RPE were significantly lower during DP (p ≤ 0.05) while no differences were detected between AP and CL. Session x set interactions (p ≤ 0.05) were observed for repetition performance, mean velocity, peak velocity, VL, and set-RPE, but differences were likely influenced by fluctuating relative intensities during AP and DP. Data also revealed that lifters from G2 executed their repetitions with greater mean and peak velocities than G1 (p ≤ 0.05), suggesting that relative strength influences barbell velocity. In conclusion, AP, CL, and DP are viable options for training sessions, but the latter may negatively affect peak velocity.
... Moreover, the fact that Metric VBT reports the mean velocity of the barbell rather than MPV further complicates its effectiveness for VBT. MPV specifically measures the velocity during the propulsive phase of a movement, excluding the braking phase where the movement slows down (Sanchez-Medina, Perez & Gonzalez-Badillo, 2010). This phase represents the portion of the movement when the muscles exert force to accelerate the resistance load. ...
... Similarly, setting the velocity threshold too high might lead to the exclusion of valid data where the velocity is slightly less than 0.1 m/s but still represents significant muscular effort. Since MPV offers a more accurate reflection of performance than mean velocity, particularly at moderate or lighter exercise intensities (Sanchez-Medina, Perez & Gonzalez-Badillo, 2010), it is vital for any VBT tool to include this capability. ...
Background
Velocity-based training (VBT) is commonly used for programming and autoregulation of resistance training. Velocity may also be measured during resistance training to estimate one repetition maximum and monitor fatigue. This study quantifies the validity of Metric VBT, a mobile application that uses camera-vision for measuring barbell range of motion (RoM) and mean velocity during resistance exercises.
Methods
Twenty-four participants completed back squat and bench press repetitions across various loads. Five mobile devices were placed at varying angles (0, ±10, and ±20°) perpendicular to the participant. The validity of Metric VBT was assessed in comparison to Vicon motion analysis using precision and recall, Lin’s concordance correlation coefficient, and Bland-Altman plots. Proportional bias was assessed using linear regression.
Results
Metric VBT accurately detected over 95% of repetitions. It showed moderate to substantial agreement with the Vicon system for measuring RoM in both exercises. The average Limits of Agreement (LoA) for RoM across all camera positions were −5.45 to 4.94 cm for squats and −5.80 to 3.55 cm for bench presses. Metric VBT exhibited poor to moderate agreement with the Vicon system for measuring mean velocity. The average LoA for mean velocity were 0.03 to 0.25 m/s for squats and −5.80 to 3.55 m/s for bench presses. A proportional bias was observed, with bias increasing as repetition velocity increased.
Conclusions
Metric VBT’s wide LoA for measuring RoM and mean velocity highlights significant accuracy concerns, exceeding acceptable levels for practical use. However, for users prioritizing repetition counts over precise RoM or mean velocity data, the application can still provide useful information for monitoring workout volume.
... In addition, during the test, participants received verbal encouragement from the research team [27]. A Chrono Jump ® linear encoder and Chrono Jump version 1.4.6.0 ® software (Barcelona, Spain) were used to evaluate 1RM in HBS [28]. ...
... In addition, during the test, the participants received verbal encouragement from the research team [27]. A Chrono Jump ® linear encoder and Chrono Jump version 1.4.6.0 ® software (Barcelona, Spain) were used to evaluate the four HBS replicates [28]. In the statistical analysis, mean velocity (m·s −1 ), mean power (W), mean force (N), and RFD (N/s) were the variables used to quantify differences in performance before and after 14 days of creatine supplementation. ...
The use of creatine monohydrate (Cr) in professional soccer is widely documented. However, the effect of low doses of Cr on the physical performance of young soccer players is unknown. This study determined the effect of a low dose of orally administered Cr on muscle power after acute intra-session fatigue in young soccer players. Twenty-eight young soccer players (mean age = 17.1 ± 0.9 years) were randomly assigned to either a Cr (n = 14, 0.3 g·kg⁻¹·day⁻¹ for 14 days) or placebo group (n = 14), using a two-group matched, double-blind, placebo-controlled design. Before and after supplementation, participants performed 21 repetitions of 30 m (fatigue induction), and then, to measure muscle power, they performed four repetitions in half back squat (HBS) at 65% of 1RM. Statistical analysis included a two-factor ANOVA (p ˂ 0.05). Bar velocity at HBS, time: p = 0.0006, ŋp2 = 0.22; group: p = 0.0431, ŋp2 = 0.12, time × group p = 0.0744, ŋp2 = 0.02. Power at HBS, time: p = 0.0006, ŋp2 = 0.12; group: p = 0.16, ŋp2 = 0.06, time × group: p = 0.17, ŋp2 = 0.009. At the end of the study, it was found that, after the induction of acute intra-session fatigue, a low dose of Cr administered orally increases muscle power in young soccer players.
... Based on the evidence, load and velocity factors influence asymmetry levels, suggesting that higher velocities can improve symmetry [5]. Considering this factor, studies establish speed as an important component in performance evaluation [14][15][16][17][18]. Still in this sense, when the velocity was investigated with an intensity of 50%, a symmetrical performance was found, while with an intensity of 90%, there was significant asymmetry in favor of the dominant limb, observed in the initial and final moments of the movement [8]. ...
... To test our hypothesis regarding the intensity and phases of the movement (eccentric and concentric), we compared the speed at each moment, between repetitions, with an intensity of 45% and 80% 1RM. The intensity of 45% 1RM allowed a good representation of the effect of the load on the velocity kinetics, it is easily moved and tolerated by the athletes, in addition to being the load that causes an average velocity of one meter per sec, in agreement with [15,18,32]. These characteristics of the 45% 1RM load may justify and demonstrate the little difference in asymmetry in welltrained PP athletes. ...
Background
Para Powerlifting (PP) is the bench press with a single contest exercise. The rules require symmetry in lifting, but the natural tendency among humans is for asymmetry.
Objective
The aim of the present study was to examine the influence of speed, load intensity, and fatigue of a training session on symmetry, and analyze asymmetries of average speeds between the limbs after a training session.
Methods
Twelve male PP athletes (age 28.58 ± 5.50 years, experience 4.53 ± 1.27 years, body mass 79.25 ± 18.82 kg, 1RM 150.42 ± 42.07 kg, 1RM/BM 1.94 ± 0.46), had their bench press lifts recorded and downloaded into the Kinovea software. Measures of central tendency, mean ± standard deviation (SD) and the Shapiro–Wilk test were performed.
Results
There was a difference in repetition 2, in the dominant limb, between the moment before and after, however, our hypothesis that at higher intensities and in the concentric phase of the exercise it would cause velocity asymmetry between the limbs was not confirmed.
Conclusion
It is important to observe the absolute data and carefully evaluate the statistical differences since asymmetries are observed in different sports and are not determinant in sports performance; thus, being acceptable up to a certain level and unfavorable when it exceeds this level, which is individual and intimate to the sports activity.
... The performance was measured using an isoinertial dynamometer (T-Force Dynamic Measurement System, Ergotech, Murcia, Spain) attached to the subjects' hips with a harness. The trials with the highest and lowest mean velocity values of the propulsive phase (net force > 0 [15]) were excluded, and the average of the remaining three trials was calculated [16]. The average propulsive velocity, force, and power were obtained. ...
This study aimed to investigate the relationship between the load–velocity profile and sprint swimming performance and kinematics, explore the inter-relationships of the load–velocity profile variables and blood lactate concentrations [La−] and dry-land strength (pull-ups), and examine sex-based differences. Twenty-seven swimmers (15 males: 19.2±3.7 y; 50 m front-crawl 550±70 World Aquatics points; 12 females: 17.7±2.4 y; 50 m front-crawl 552±63 World Aquatics points) underwent a 50 m front-crawl all-out swim test, a load–velocity profile test, and a pull-up test. Theoretical maximum velocity was associated with sprint swimming performance (r>0.863 and p<0.001), but not the theoretical maximum load (L 0) or the slope (p>0.05) for both sexes. An association between kinematics during the load–velocity profile test and free swimming was weakened as the load increased, with the correlation coefficient (r) decreasing from 0.929 to 0.403. Theoretical maximum velocity and theoretical maximum load were primarily associated with both sexes with the first (r>0.950 and p<0.001) and last (r>0.849 and p<0.001) semi-tethered trials, respectively. Only in females [La−] was associated with the theoretical maximum load and slope (r>0.573 and p<0.05). Males exhibited greater values than females in all the assessed variables (p<0.05) except for stroke rates and [La−]. The load–velocity profile is a valuable tool for assessing performance in both sexes. Kinematic parameters were related between semi-tethered and free swimming; however, association diminished with increasing load.
... The upper limb circumference test was performed using a tape measure, measuring both the relaxed and tensed circumferences at the apex of the biceps brachii. The bench press means propulsive power (BPP) is utilized to assess the upper limb strength of participants 20 . These tests are performed on a Smith machine to eliminate the influence of horizontal displacement on the results. ...
This study evaluates the impact of 4 weeks of 40% arterial occlusion pressure (AOP) blood flow restriction (BFR) combined with repeated sprint training (RST) on the microcirculation function of upper limbs in boxers and investigates the potential mechanisms underlying improvements in microcirculation from the perspective of blood factor changes. Thirty-six healthy male collegiate boxers were assigned to either a blood flow restriction training group (Experimental Group, EG, n = 18) or a conventional training group (Control Group, CG, n = 18), completing 12 sessions over 4 weeks (three sessions per week). The training regimen for EG and CG was identical, except EG underwent BFR during the training sessions. Measurements of arm circumference, muscle strength, microcirculation function (4 indicators), and blood factor (4 indicators) were taken one day before training began and the day after the final training session. Using two-factor repeated measures ANOVA, significant differences were observed in EG’s arm circumference at tension, muscle strength, microvascular blood flow perfusion, transcutaneous oxygen pressure, muscle oxygen saturation, nitric oxide levels, endothelial nitric oxide synthase, endothelin-1, and vascular endothelial growth factor, all showing improvements from baseline. In contrast, CG only demonstrated increased upper limb strength, with no significant changes in the other indicators. These findings suggest that while both training protocols may enhance muscle strength, the addition of BFR notably improves upper limb microcirculation and muscle strength in collegiate boxers by modulating the secretion of blood factors such as endothelial nitric oxide synthase, endothelin-1, and vascular endothelial growth factor.
... The dynamic strength parameters, MPV, Vmax, and power, were recorded using a Speed4Lift encoder (Vitruve, Madrid, Spain) [39]. The analysis of these parameters was performed using a load of 45% of 1RM, where the velocity was approximately 1.0 m·s −1 [40,41]. A load of 80% of 1RM was also used, given that this is normally the load used in strength training [42]. ...
Background: Among the strength sports we have Paralympic powerlifting, and the factors that influence strength have been investigated; among them is the relationship between strength and the ratio of the size of the second and fourth fingers of the hand (2D:4D).
Objectives: The study is aimed at evaluating the relationship between the 2D:4D finger length ratio and the dynamic strength indicators, mean propulsive velocity (MPV), maximum velocity (Vmax), and power, with loads of 45% and 80% of one repetition maximum (1RM), in Paralympic powerlifting.
Methodology: Sixteen elite Paralympic powerlifting athletes were evaluated for dynamic strength indicators, MPV, Vmax, and power, with loads of 45% and 80% 1RM. The 2D:4D proportions and correlations between the indicators were evaluated of 2D:2D ratios and dynamic strength indicators.
Results: Moderate correlations were found between MPV 45% and 4D (r=0.551, p=0.027), between MPV 45% and R-L 2D:4D diff. (r=−0.595, p=0.015), between power 80% and L2 (r=0.542, p=0.030), and between MPV 45% and R-L 2D:4D (r=−0.585, p=0.017). There was also a moderate correlation between power 80% left 2D (r=−0.542, p=0.030). However, no correlation was found between the 2D:4D ratios and dynamic strength indicators in Paralympic powerlifting.
Conclusion: The 2D:4D ratio presents a moderate correlation with dynamic strength indicators in Paralympic powerlifting athletes, where the ratios with the velocity of 45 of 1RM can be used as a predictor but with caution.
... The linear velocity transducer recorded the MPV and eccentric displacement during each repetition. The propulsive phase was defined as the part of the concentric movement where the measured acceleration exceeded gravitational acceleration [21]. Velocity was sampled at a frequency of 1000 Hz and processed using custom software (T-Force Dynamic Measurement System, version 2.3). ...
Combining aerobic and strength training may attenuate neuromuscular adaptations, particularly when both target the same muscle group. This study assessed whether separating the training modalities by muscle groups mitigates this interference. Ninety‐six participants (56 males and 40 females) completed a 12‐week intervention, divided into three groups: (1) LHLS (lower‐body high‐intensity interval (HIIT) and strength training), (2) LHUS (lower‐body HIIT and upper‐body strength training), and (3) LSUS (lower‐ and upper‐body strength training). Maximal (1RM) and explosive strength were assessed using load–velocity profiling, with mean propulsive velocity (MPV) at 30%, 50%, 70%, and 90% of 1RM as a measure of explosive strength. Muscle cross‐sectional area (CSA) of the M. vastus lateralis and M. pectoralis major was measured using panoramic ultrasound. Lower‐body adaptations were compared between LHLS and LSUS, and upper‐body adaptations were compared between LHUS and LSUS. MPV at 70% and 90% of 1RM for the squat (LHLS and LSUS) and bench press (LHUS and LSUS) showed improvements (p < 0.050), with no significant between‐group differences. Squat 1RM improved in both LHLS and LSUS, and bench press 1RM increased in both LHUS and LSUS (all p < 0.001). M. vastus lateralis CSA increased in LHLS (p = 0.029) but not in LSUS, whereas M. pectoralis major CSA increased in both LHUS and LSUS (p < 0.001), with no between‐group differences. No sex‐based differences were observed. Concurrent aerobic and strength training does not impair explosive strength, maximal strength, or muscle hypertrophy, regardless of whether the same or separate muscle groups are targeted.
... The PV attained against loads relative or absolute loads is an important indicator of physical performance [33,34]. Generally speaking, considering the close relationship between relative load and movement velocity [35], we can infer that subjects who can move 40% and 80% of 1RM faster after any type of acute or chronic intervention are also able to apply greater amounts of force against other maximal or submaximal loads (including at the 1RM load) [35,36]. Therefore, the significant increment (+ 7.1%) (Figure 3) in PV at 40% 1RM observed 24-h after the "light" (JS at 40% ...
Priming activities have been widely used by coaches as a strategy to enhance physical performance within short periods (6–24 hours) before sport-specific training sessions and competitions. In this crossover study, we examined and compared the effects of two different priming schemes on the speed-power performance of female rugby sevens players. One hour after completing a standardized warm-up and a series of measurements including loaded and unloaded jumps and speed-related tests, twenty Olympic female rugby sevens players performed, one week apart, 6 sets of 6 reps of jump-squats (JS) at either 40% (light-load; LL) or 80% 1RM (heavy-load; HL). Countermovement jump height increased significantly 6-h after both loading conditions (ES=0.50 and 0.34, for LL and HL, respectively; P < .001), with no changes observed at the 24-h time-point. JS peak velocity improved significantly after 24-h compared to the pre-testing, but solely for the lighter loading intensity (i.e., JS at 40%1RM; ES=0.63; P=0.006). 40-m sprinting speed increased significantly at the 6-h timepoint for both LL (ES=0.20; P=0.001) and HL (ES=0.18; P=0.004), without showing significant changes in the following 24-h. COD speed improved significantly after both priming schemes at the 6- and 24-h time points, regardless of the loading condition (P ≤ 0.027 for the main effect of time). No time × loading condition interaction was detected for any variable assessed, with P-values ranging from 0.111 to 0.953. Importantly, the rate of perceived exertion was significantly higher after the priming protocol at the HL condition (P=0.02), which may lead to increased levels of fatigue and decreased performance in subsequent activities. Elite coaches from rugby sevens (and other team sports) should strongly consider these findings when programming priming training sessions in the periods preceding more intensive training sessions and official matches due to the potential disadvantages associated with the use of heavier loads (i.e., ≥ 80% 1RM).
... In the BPT, the MPV and PV during the concentric phase were obtained. MPV is defined as the average velocity from the start of the concentric phase of the repetition until the moment peak velocity is achieved [44]. For data analysis, we used the average of the MPV and PV from the three BPTs recorded at each time point. ...
Background: The tempo of resistance exercises is known to influence performance outcomes, yet its specific effects on post-activation performance enhancement (PAPE) remain unclear. This study aimed to investigate the effects of fast versus slow repetitions at a load of 70% of one-repetition maximum (1-RM) in the bench press exercise, focusing on velocity, surface electromyographic (sEMG) activity, and applied force while equating time under tension on bench press throw performance. Methods: Eleven men (age: 23.5 ± 5.4 years, height: 1.79 ± 0.04 m, body mass: 79.1 ± 6.4 kg, maximum strength 1-RM: 91.0 ± 12.0 kg) participated. Two experimental conditions (FAST and SLOW) and one control (CTRL) were randomly assigned. Participants performed two sets of six repetitions as fast as possible (FAST condition) and two sets of three repetitions at a controlled tempo (SLOW condition) at half the concentric velocity of FAST, as determined in a preliminary session. Before and after the bench press participants performed bench press throws tests (Pre, 45 s, 4, 8, and 12 min after). Results: sEMG activity and peak force during the bench press were higher in FAST vs. SLOW conditioning activity (p < 0.001), with time under tension showing no significant differences between conditions (p > 0.05). Mean propulsive velocity (MPV) during the bench press throw improved equally in both FAST and SLOW conditions compared with baseline from the 4th to the 12th min of recovery (FAST: +6.8 ± 2.9% to +7.2 ± 3.3%, p < 0.01, SLOW: +4.0 ± 3.0% to +3.6 ± 4.5%, p < 0.01, respectively). Compared to the CTRL, both conditions exhibited improved MPV values from the 4th to 12th min (p < 0.01). Peak velocity improvements were observed only after the FAST condition compared to the baseline (p < 0.01) with no differences from SLOW. For all muscles involved and time points, sEMG activity during bench press throws was higher than CTRL in both experimental conditions (p < 0.01), with no differences between FAST and SLOW. Peak force increased in both FAST and SLOW conditions at all time points (p < 0.05), compared to CTRL. Conclusions: These findings suggest that post-activation performance enhancement is independent of movement tempo, provided that the resistive load and total time under tension of the conditioning activity are similar. This study provides valuable insights into the complex training method for athletes by demonstrating that varying tempo does not significantly affect post-activation performance enhancement when load and TUT are equated.
... Progressive loading test. The individual load-velocity (L-V) relationships and 1RM load in the SQ exercise were determined using a Smith machine with no counterweight mechanism (Multipower Fitness Line, Peroga, Murcia, Spain) and a linear velocity transducer (T-Force System Ergotech, Spain), whose reliability has been reported elsewhere (34). During each repetition, subjects started from the upright position with the knees and hips fully extended, ...
This study compared the effects of four different resistance training (RT) programs that differed in the set configuration (cluster vs. traditional) and the blood flow condition [free-flow (FF) vs. blood flow restriction (BFR)] on strength, neuromuscular and hypertrophic adaptations.
Methods: Forty-two resistance-trained males were randomly assigned into four protocols that differed in the set configuration (TRA: without rest between repetitions vs. CLU: 30 s rest every 2 repetitions) and in the blood flow condition [FF vs. BFR (50% of arterial occlusion pressure)]. Subjects followed an 8-week RT program, twice per week, with similar intensity (55%–65% 1RM), sets (3), repetitions per set (10-6), and resting time (2 minutes) in the full-squat (SQ) exercise. Before and after the RT program, they were evaluated for: 1) muscle size of the vastus lateralis; 2) vertical jump; 3) maximal isometric contraction; 4) progressive loading test; and 5) fatigue test.
Results: BFR-TRA and FF-CLU induced greater increases in 1RM, and velocity against submaximal loads than FF-TRA and BFR-CLU (BFR × time and CLU × time interactions, p = 0.02). The TRA protocols showed greater increases in maximal isometric force than CLU (CLU × time interaction, p = 0.03). BFR did not enhance jump performance unlike the FF protocols (p < 0.01). The TRA protocols induced greater hypertrophy in the distal region of the vastus lateralis than CLU protocols (CLU × time interaction, p = 0.04), with BFR-TRA producing the greatest gains in all vastus lateralis sections.
Conclusions: The different combinations of set configurations and blood flow conditions resulted in highly specific adaptations that illustrate the potential of adaptation for each protocol. The divergent underlying mechanisms of CLU and BFR methodologies may offset each other when combined.
... During these sessions, the participants got familiarized with the bent over row exercise while the exercise professional emphasized the technique and the intention to move the loads at maximum velocity of the concentric phase. The individualized loadvelocity relationships were modulated using thee different velocity variables: (1) MV: the average velocity from the start of the upward movement (i.e., the first positive velocity value) until the barbell reaches the maximum height (i.e., the velocity is 0 m·s −1 ); (2) MPV: the average velocity during the impulsive phase, defined as the part of the concentric phase during which the measured acceleration is greater than the acceleration due to gravity (i.e., a ≥ − 9.81 m·s −2 ) [28]; and (3) PV: the highest velocity value recorded at a particular instant (m·s −1 ) during the concentric phase. The individualized load-velocity relationships were modulated by two different regression models: linear and polynomial. ...
Purpose
Resistance training mitigates side effects during and after cancer treatment. To provide a new approach for precisely and safely assessing and prescribing the intensity of resistance training in supportive cancer care, the purpose of this study was to evaluate the load-velocity relationship during the row exercise in women survivors of breast cancer.
Methods
Twenty women survivors of breast cancer who had undergone surgery and had completed core breast cancer treatment within the previous 10 years completed an incremental loading test until the one repetition maximum (1RM) in the row exercise. The velocity was measured during the concentric phase of each repetition with a linear velocity transducer, and their relationship with the relative load was analyzed by linear and polynomial regression models.
Results
A strong relationship was observed between movement velocity and relative load for all measured velocity variables using linear and polynomial regression models (R² > 0.90; SEE < 6.00%1RM). The mean velocity and mean propulsive velocity of 1RM was 0.40 ± 0.03 m·s⁻¹, whereas the peak velocity at 1RM was 0.64 ± 0.07 m·s¹.
Conclusion
In women survivors of breast cancer, monitoring movement velocity during the row exercise can facilitate precise assessment and prescription of resistance training intensity in supportive cancer care.
... A linear velocity transducer (T-Force System, Ergotech) was used for recording the mean propulsive velocity (MPV) of every repetition. 20 An average of 6.1 (1.1) increasing loads were used for each subject. Only the fastest repetition with each load was considered for subsequent analyses. ...
Purpose: This study explored the effects of 4 bench-press (BP) training programs with different velocity-loss (VL) thresholds (0%, 15%, 25%, and 50%) on strength gains and neuromuscular adaptations. Methods: Forty-six resistance-trained men (22.8 [4.4] y) were randomly assigned into 4 groups that differed in the VL allowed within the set: 0% (VL0), 15% (VL15), 25% (VL25), and 50% (VL50). Training loads (40%–55% 1-repetition maximum), frequency (2 sessions/wk), number of sets (3), and interset recovery (4 min) were identical for all groups. Participants completed the following tests before and after an 8-week (16-session) BP training program: (1) maximal isometric test, (2) progressive loading test, and (3) fatigue test in the BP exercise. During all tests, triceps brachii muscle electromyography was assessed. Results: After completing the resistance-training program, no significant group × time interactions were noticed for isometric and dynamic BP strength variables. The dose–response relationship exhibited an inverted U-shaped relationship pattern, with VL25 showing the greatest effect sizes for almost all strength variables analyzed. The total number of repetitions performed during the training program increased as the VL magnitude increased. Conclusions: The group that trained with high VL threshold (50%), which performed a total of 876 repetitions, did not experience additional strength gains compared with those experienced by the 0%, 15%, and 25% of VL groups, which performed significantly fewer repetitions (48, 357, and 547, respectively). These findings suggest that when light loads (40%–55% 1-repetition maximum) are used, low and moderate VL thresholds (0%–25%) provide a higher training efficiency.
... The reasons for this discrepancies might be related to (I) the exercise chosen, since they performed the flat bench press and our study analysed the decline; (II) differences in body mass between males and females in their study vs ours (13.8 vs 29.4 kg, respectively) because, as previously stated, this difference, if attributed to greater hypertrophy, might contribute to greater force production and (III) their study used mean velocity as the variable, whereas we chose to study MPV. Evidence shows that MPV is more precise, especially when using light and medium loads and therefore is the preferred variable when analysing isoinertial strength training (Sanchez-Medina et al., 2010). ...
The purpose of this study was to analyse the load-velocity and load-power relationships of the decline bench press exercise (DBPE) and to compare sex-related differences. Twelve young healthy men and women performed a progressive loading test for the determination of 1RM strength and individual load-velocity and load-power relationship in the DBPE. A very close relationship between mean propulsive velocity (MPV) and %1RM was observed (R2 = 0.94). This relationship improved when plotting data separately by sex (R2 = 0.96–97). Individual load-velocity profiles gave an R2 = 0.99 ± 0.01. The relationship between mean propulsive power (MPP) and %1RM was R2 = 0.23. When separating data by sex, R2 = 0.64–73 were obtained. Individual load-power profiles gave an R2 of 0.93 ± 0.07. Significant sex-related differences were found for MPV, with males having faster velocities than females from 30% to 40% 1RM (p = 0.01) and for MPP, with males having greater MPP (W) than females from 30% to 95% 1RM (p < 0.001). The results of this study show that a strong correlation exists between relative load and MPV/MPP in the DBPE, allowing the possibility of using one to predict the other with great precision, especially when a sex-specific equation is used.
... It was forbidden to throw the bar. The velocity variable used in this study was the MPV, which is described as the concentric action during which the measured acceleration is greater than the acceleration due to gravity ( − 9.81 m · s -2 ) [25]. The warmup consisted of one set of 6 BP repetitions with 20 kg. ...
The aim of this study was to examine the acute metabolic response, neuromuscular activity, and mechanical performance of different set configurations in bench-press (BP). Twenty-two resistance-trained men performed three resistance exercise protocols consisting of 3 x 12 BP repetitions at 60 % 1RM, with 4 minutes of rest between sets, but with different set configurations: (a) traditional set (TS), without rest within the set; (b) cluster-6 (CS6), with 30-second intraset rest after the sixth
repetition in each set; and (c) cluster-2 (CS2), with 30-second intraset rest every two repetitions. Mean propulsive force (MPF), velocity (MPV), power (MPP), and electromyography (EMG) values were recorded for each repetition. Blood lactate, maximal voluntary isometric BP contraction, and dynamic strength in BP were assessed pre- and post-exercise. The CS2 protocol resulted in greater mechanical performance (i. e. MPF, MPV, and MPP) and lower alterations of EMG parameters (i. e. root mean square and median frequency) during the exercise compared to CS6 and TS (TS < CS6 < CS2). The CS2 protocol induced smaller increases in lactate compared to TS and CS6. No significant “protocol x time” interactions were observed for the MVIC (maximal voluntary isometric BP contraction) variables. Introducing short but frequent intraset rest periods alleviates training-induced fatigue assessed by better performance maintenance.
... The faster movement when exercising at FULL than at partial ROM has been previously reported in the literature (Drinkwater et al., 2012;Krzysztofik et al., 2020, and this is explained by the longer propulsive phase, which is coupled with a longer acceleration phase, resulting in higher peak and mean velocity compared with any shorter ROM partial repetition. Notably, the propulsive phase constitutes 93% of the concentric duration in the bench press exercise at a similar load as that used in the present study, i.e., 65% of 1-RM (Sanchez-Medina et al., 2010). Thus, the ~20% higher mean and peak barbell velocity in FULL along with the higher work done per repetition compared with the partial ROM conditions may have contributed to the greater rate of fatigue and the lower number of repetitions. ...
This study compared the acute effects of different ranges of motion (ROM) on fatigue and metabolic responses during repeated sets of bench press exercise. Ten resistance trained men performed three sets to momentary failure with two-min rest intervals at three different ROM: full ROM (FULL), and partial ROM in which the barbell was moved either at the bottom half (BOTTOM) or the top half (TOP) of the full barbell vertical displacement. In TOP, a higher load was lifted, and a higher total number of repetitions was performed compared to FULL and BOTTOM (130 ± 17.6 vs. 102.5 ± 15.9 vs. 98.8 ± 17.5 kg; 55.2 ± 9.8, 32.2 ± 6.5 vs. 49.1 ± 16.5 kg, respectively p < 0.01). Work per repetition was higher in FULL than TOP and BOTTOM (283 ± 43 vs. 205 ± 32 vs. 164 ± 31 J/repetition, p < 0.01). Mean barbell velocity at the start of set 1 was 21.7% and 12.8% higher in FULL compared to TOP and BOTTOM, respectively. The rate of decline in mean barbell velocity was doubled from set 1 to set 3 (p < 0.01) and was higher in FULL than both TOP and BOTTOM (p < 0.001). Also, the rate of mean barbell velocity decline was higher in BOTTOM compared to TOP (p = 0.045). Blood lactate concentration was similarly increased in all ROM (p < 0.001). Training at TOP ROM allowed not only to lift a higher load, but also to perform more repetitions with a lower rate of decline in mean barbell velocity. Despite the lower absolute load and work per repetition, fatigue was higher in BOTTOM than TOP and this may be attributed to differences in muscle length.
... This momentary pause between the eccentric and concentric phases was applied to minimize the influence of the rebound effect and to allow for more consistent measurements. 33 No barbell bouncing on the chest, shoulder lifting, or torso off the bench were allowed. In the SQ exercise, the participants began with their knees and hips fully extended in an upright position with feet shoulderwidth apart and the bar resting on the trapezius. ...
Background: The aim of this study was to determine the influence of different percentages of blood flow restriction (BFR) and loads on mean propulsive velocity (MPV) and subjective perceived exertion during squat (SQ) and bench press (BP) exercises.
Hypothesis: Higher percentages of BFR will positively affect dependent variables, increasing MPV and reducing perceived exertion.
Study Design: Cross-sectional study.
Level of Evidence: Level 3.
Methods: Eight healthy young male athletes took part. Two sets of 6 repetitions at 70% 1-repetition maximum (1RM), 2 sets of 4 repetitions at 80% 1RM, and 2 sets of 2 repetitions at 90% 1RM were performed randomly; 5-minute recoveries were applied in all sets. The varying arterial occlusion pressure (AOP) applied randomly was 0% (Control [CON]), 80%, and 100%.
Results: No statistically significant differences in MPV were found during the BP exercise at any percentage of BFR at any percentage 1RM. During the SQ exercise, MPV results showed statistically significant increases of 5.46% (P = 0.04; ηp2 = 0.31) between CON and 100% AOP at 90% 1RM. The perceived exertion results for the BP exercise showed statistically significant reductions of -8.66% (P < 0.01; ηp2 = 0.06) between CON and 100% AOP at 90% 1RM. During the SQ exercise, the perceived exertion results showed significant reductions of -10.04% (P = 0.04; ηp2 = 0.40) between CON and 100% AOP at 80% 1RM; -5.47% (P = 0.02; ηp2 = 0.48) between CON and 80% AOP at 90% 1RM; and -11.83% (P < 0.01; ηp2 = 0.66) between CON and 100% AOP at 90% 1RM.
Conclusion: BFR percentages ~100% AOP at 90% 1RM improved acutely MPV (only in SQ exercises) and reduced acutely perceived exertion (in both exercises). These findings are important to consider when prescribing resistance training for healthy male athletes.
... As previously mentioned, each swimmer performed three repetitions with each selected load. Only the best repetition at each load, according to the criteria of fastest mean propulsive velocity, was further considered for the analysis [36]. Five minutes of rest were allowed in between to achieve a complete recovery. ...
This study aimed to identify the relationship between dryland tests and swimming performance in elite Paralympic swimmers. Fifteen competitive swimmers (age: 27.4 ± 5.4 years, height: 1.70 ± 6.8 m, body mass: 67.9 ± 9.2 kg; 9 males, 6 females) performed a lat pull-down and a bench press incremental load test to determine maximum power (Pmax), the strength corresponding to maximum power (F@Pmax), and the barbell velocity corresponding to maximum power (V@Pmax) from the force–velocity and power–velocity profiles. These outcomes were also normalized by the athlete’s body mass. Swimming performance was carried out from the best result in a 100 m freestyle race registered during an international competition. Lat pull-down F@Pmax was significantly associated with 100 m freestyle chronometric time (ρ = −0.56, p < 0.05), and lat pull-down V@Pmax presented a relationship with mean swimming velocity (ρ = 0.71, p < 0.01). Similarly, bench press F@Pmax and the normalized F@Pmax were significantly related to the mean swimming velocity (ρ = −0.51, ρ = −0.62, p < 0.05). Stepwise multiple regression showed that lat pull-down V@Pmax, bench press normF@Pmax, and V@Pmax accounted for 40.6%, 42.3%, and 65.8% (p < 0.05) of the mean swimming velocity variance. These preliminary results highlighted that simple dryland tests, although with a moderate relationship, are significantly associated with 100 m freestyle swimming performance in elite Paralympic swimmers.
... 3, 4, but no significant percentage loss was observed during the sets of training. The use of MPV as a reliable indicator for strength analysis has been well-documented in the literature since 2010 [20], including its application for assessing neuromuscular fatigue. However, most of these analyses have focused on specific interventions targeting muscular endurance and 1RM prediction [21,22]. ...
Mean propulsive velocity (MPV) has been associated with neuromuscular fatigue; however, its suitability for strength training in Paralympic powerlifting (PP) remains uncertain. The objective of this work was to evaluate the MPV in two training methods (traditional-TRAD and eccentric-ECC). Eleven PP athletes were evaluated pre, during the intervention and post intervention at a load of 80% of the 1RM for TRAD and 110%–80% of 1 RM for ECC. The results demonstrated that there was no significant neuromuscular fatigue for the TRAD (~5% performance loss), as well as no significant decline in MPV during the intervention. For the ECC, there is a significant reduction in MPV before and after training (~12% loss of performance). A difference between TRAD and ECC after the intervention was also identified (0.87 m/s±0.22, 95% CI 0.72–1.02 vs. 0.72±0.20, 95% CI 0.59–0.86 p=0.042, F(3.30)=10.190, η2p=0.505 - very high effect). During the intervention for ECC, no significant decline in MPV was observed. The results of this study suggest that the mechanical indices of MPV do not seem to be effective indicators of neuromuscular fatigue in the sample studied or in the context of this specific training regime, being more indicated as a control of training volume.
... MPV corresponds to the mean velocity of the propulsive phase of each repetition. The propulsive phase was defined as that portion of the concentric phase during which the measured acceleration is greater than the acceleration due to gravity (i.e., <−9.8 m·s −2 ) [24]. For the MPV attained against 20 kg, the ICC was 0.99 (95% CI: 0.97; 0.99), and the CV was 2.4%. ...
Research on the evolution of performance throughout a season in team sports is scarce and mainly focused on men’s teams. Our aim in this study was to examine the seasonal variations in relevant indices of physical performance in female football players. Twenty-seven female football players were assessed at week 2 of the season (preseason, PS), week 7 (end of preseason, EP), week 24 (half-season, HS), and week 38 (end of season, ES). Similar to the most common used conditioning tests in football, testing sessions consisted of (1) vertical countermovement jump (CMJ); (2) 20 m running sprint (T20); (3) 25 m side-step cutting maneuver test (V-CUT); and (4) progressive loading test in the full-squat exercise (V1-LOAD). Participants followed their normal football training procedure, which consisted of three weekly training sessions and an official match, without any type of intervention. No significant time effects were observed for CMJ height (p = 0.29) and T20 (p = 0.11) throughout the season. However, significant time effects were found for V-CUT (p = 0.004) and V1-LOAD (p = 0.001). V-CUT performance significantly improved from HS to ES (p = 0.001). Significant increases were observed for V1-LOAD throughout the season: PS-HS (p = 0.009); PS-ES (p < 0.001); EP-ES (p < 0.001); and HS-ES (p = 0.009). These findings suggest that, over the course of the season, female football players experience an enhancement in muscle strength and change of direction ability. However, no discernible improvements were noted in sprinting and jumping capabilities during the same period.
... 21 The MPV of bar movement during the concentric phase was used as the analysis variable. 33 ...
Background
The perception of bar velocity loss (PVL) can be used as an alternative method for autoregulating intraset repetitions during velocity-based training. This study analyzed the accuracy and reliability of the PVL as a method to autoregulate the intraset repetitions using a moderate velocity loss (VL) threshold (15–30%).
Methods
A total of 22 resistance-trained men were familiarized with the PVL in a single session. Test–retest was performed in two sessions 1 week apart, in which participants completed three sets of bench press and back squat at 40, 60, and 80% 1 repetition maximum (1RM). Participants stopped the sets when they reached a moderate VL zone using their PVL. Accuracy was assessed by analyzing whether the mean VL (actual) and the lower and upper limits of the confidence interval (CI) (95%) of each set were within the established VL range and quantifying the relative frequency of correctly interrupted sets. Test–retest reliability was examined by the intraclass correlation coefficient and coefficient of variation.
Results
PVL showed acceptable accuracy in both exercises at 60 and 80% 1RM (50–65% success rate) and retest for all loads (53–76% success rate). Similar PVL percentages were observed between most of the sets for the test and retest (p > 0.05). Accuracy improved during the retest, especially for bench press (40% 1RM) and back squat (40 and 80% 1RM). PVL was not reliable in the test–retest comparison.
Conclusion
PVL can be a strategy with acceptable accuracy to autoregulate the intraset repetitions in a moderate zone (VL15–30%), but its reliability does not appear satisfactory after one familiarization session.
... The repetition yielding the highest MPV for each load was considered for subsequent analysis. Of note, MPV corresponds to the portion of the concentric action during which the measured acceleration is greater than the acceleration because of gravity (29.81 m·s 22 ) (38). On average, the participants completed 8.5 6 1.8 loads. ...
Cornejo-Daza, PJ, Sánchez-Valdepeñas, J, Rodiles-Guerrero, L, Páez-Maldonado, JA, Ara, I, León-Prados, JA, Alegre, LM, Pareja-Blanco, F, and Alcazar, J. Vastus lateralis muscle size is differently associated with the different regions of the squat force-velocity and load-velocity relationships, rate of force development, and physical performance young men. J Strength Cond Res XX(X): 000–000, 2023—The influence that regional muscle size and muscle volume may have on different portions of the force-velocity (F-V) and load-velocity (L-V) relationships, explosive force, and muscle function of the lower limbs is poorly understood. This study assessed the association of muscle size with the F-V and L-V relationships, rate of force development (RFD) and maximal isometric force in the squat exercise, and vertical jump performance via countermovement jump (CMJ) height. Forty-nine resistance-trained young men (22.7 ± 3.3 years old) participated in the study. Anatomical cross-sectional area (ACSA) of the vastus lateralis (VLA) muscle was measured using the extended field of view mode in an ultrasound device at 3 different femur lengths (40% [distal], 57.5% [medial], and 75% [proximal]), and muscle volume was estimated considering the VLA muscle insertion points previously published and validated in this study. There were significant associations between all muscle size measures (except distal ACSA) and (a) forces and loads yielded at velocities ranging from 0 to 1.5 m·s ⁻¹ ( r = 0.36–0.74, p < 0.05), (b) velocities exerted at forces and loads ranging between 750–2,000 N and 75–200 kg, respectively ( r = 0.31–0.69, p < 0.05), and (c) RFD at 200 and 400 milliseconds ( r = 0.35–0.64, p < 0.05). Proximal and distal ACSA and muscle volume were significantly associated with CMJ height ( r = 0.32–0.51, p < 0.05). Vastus lateralis muscle size exhibited a greater influence on performance at higher forces or loads and lower velocities and late phases of explosive muscle actions. Additionally, proximal ACSA and muscle volume showed the highest correlation with the muscle function measures.
... For the repetitions with the empty bar, weight plates were set up underneath the barbell sleeves to match the height of the loaded bar conditions. Two repetitions were performed at each load, and the repetition with the highest mean velocity (MV) was used for analysis (49). Each repetition began from the static position from the floor. ...
Boffey, D, DiPrima, JA, Kendall, KL, Hill, EC, Stout, JR, and Fukuda, DH. Influence of body composition, load-velocity profiles, and sex-related differences on army combat fitness test performance. J Strength Cond Res 37(12): 2467–2476, 2023—The Army Combat Fitness Test (ACFT) became the U.S. Army's mandatory physical fitness test in April of 2022. The purpose of this study was to determine the relationship between ACFT performance and both body composition and velocity profiles and to determine sex differences for these variables. Data were collected at 2 timepoints 4 months apart, from male ( n = 55) and female ( n = 17) Army Reserve Officers' Training Corps (ROTC) cadets. Body composition was assessed with a bioelectrical impedance spectroscopy device, and cadets completed a hex bar deadlift load-velocity profile (LVP) and ACFT on separate days. Stepwise multiple regressions were used to explain the amount of variance in ACFT total score and individual event performance. Significance for statistical tests was defined as an alpha level of p ≤ 0.05. Muscle mass and body fat percentage accounted for 49% of shared variance of total ACFT score, and deadlift maximal power and maximal velocity accounted for 67% of shared variance of total ACFT score. The 3 repetition maximum deadlift, standing power throw, hand-release push-up, and sprint-drag-carry events favored cadets with more muscle mass, whereas the leg tuck was influenced by the body fat percentage and the 2-mile run was affected by fat mass. Sex had greater predictive capability for the 2-mile run than body composition. Men outperformed women on all individual events, with the greatest differences on standing power throw and sprint-drag-carry. It is recommended that Army ROTC cadets taking the ACFT maximize lower-body power production and increase muscle mass.
This study aimed to analyze the evolution of repetition velocity throughout a set until failure in the bench-press exercise and to analyze the relationships between the percentage of performed repetitions (%Rep) regarding the maximum number of repetitions that can be completed (MNR) and the percentage of velocity loss (VL) in women. Sixteen women performed one set until failure with four different intensities (50%, 60%, 70%, and 80% of one-repetition maximum, 1RM). Two-testing sessions were performed with 50% and 80% 1RM to evaluate data stability. The level of significance was set at p ≤ 0.05. A close relationship was observed between the magnitude of VL and the %Rep (R² = 0.85–0.92) and a low standard error of the estimation (6.85–9.81%). Regarding reliability, the MNR showed a coefficient of variation (CV) of 16.1% and 20.8% for 50% and 80% 1RM, respectively. Regarding the %Rep for a given VL (from 15% VL), CVs were: 6.3–19.6%, being higher when VL reached in the set was lower. This study shows the usefulness of monitoring VL to estimate, with considerable precision, the %Rep in women. However, the %Rep when a given VL was reached revealed only satisfactory absolute reliability from a certain VL threshold (>15% VL).
Objective
The aim of this study was to examine the acute effects on mechanical, neuromuscular, metabolic, and muscle contractile responses to different set configurations in full-squat (SQ).
Methods
Twenty-two men performed three SQ sessions that consisted of 3 sets of 12 repetitions with 60% 1RM with 4 minutes inter-set rests: a) traditional set (TS): no rest within the set; b) cluster-6 (CS6): a 30 seconds intraset rest after the 6th repetition of each set; and c) cluster-2 (CS2): a 30 seconds intraset rest every 2 repetitions. Mechanical (i.e., force, velocity, and power) and electromyography (EMG) values were recorded for every repetition. A battery of tests was performed: a) tensiomyography (TMG), b) blood lactate c), countermovement jump (CMJ), d) maximal isometric SQ, and e) performance with the load that resulted in a velocity of 1 m·s−¹ at baseline (V1-load). Repeated measured ANOVA analyses were used to compare the 3 protocols.
Results
As the number of intraset rests increased (TS < CS6 < CS2), mechanical performance was better maintained (p < 0.01) and EMG variables were less altered (p = 0.05). At post, CS2 and CS6 displayed lower lactate concentration, lesser reductions in CMJ height, and smaller alterations in TMG-derived variables than TS (p < 0.05).
Conclusion
The introduction of short and frequent intraset rest periods during resistance exercise alleviates training-induced fatigue, resulting in better maintenance of performance. This approach can be applied during the in-season period when minimizing fatigue is a priority.
Purpose: This study compared the effects of off- and on-bike resistance training (RT) on endurance cycling performance as well as muscle strength, power and structure. Methods: Well-trained male cyclists were randomly assigned to incorporate two sessions/week of off- (full squats, n=12) or on-bike (all-out efforts performed against very high resistances and thus at very low cadences, n=12) RT during 10 weeks, with all RT-related variables [number of sessions, sets, and repetitions, duration of recovery periods, and relative loads (70% of one-repetition maximum)] matched between the two groups. A third, control group (n=13) did not receive any RT stimulus but all groups completed a cycling training regime of the same volume and intensity. Outcomes included maximum oxygen uptake (V ̇ O2max), off-bike muscle strength (full
squat) and on-bike (‘pedaling’) muscle strength and peak power capacity (Wingate test), dual-energy X-ray absorptiometry-determined body composition (muscle/fat mass), and muscle structure (cross-sectional area, pennation angle). Results: No significant within/between-group effect was found for V ̇ O2max. Both the off- (mean Δ=2.6-5.8%) and on-bike (4.5-7.3%) RT groups increased squat and pedaling-specific strength parameters after the intervention compared to the control group (–5.8-–3.9%) (p<0.05) with no significant differences between them. The two RT groups also increased Wingate performance (4.1% and 4.3%, respectively, vs. –4.9% in the control group, p≤0.018), with similar results for muscle cross-sectional area (2.5% and 2.2%, vs. –2.3% in the control group, p≤0.008). No significant within/between-group effect was found for body composition. Conclusions: The new proposed on-bike RT could be an effective alternative to conventional off-bike RT training for improving overall and pedaling-specific muscle strength, power, and muscle mass.
The purpose of this study was to determine the 1 repetition maximum (1RM) of the jump shrug (JS) using the barbell acceleration characteristics of repetitions performed with relative percentages of the hang power clean (HPC). Fifteen resistance-trained men (age=25.5±4.5 years, body mass=88.5±15.7 kg, height=176.1±8.5 cm, relative 1RM HPC=1.3±0.2 kg·kg-1) completed two testing sessions that included performing a 1RM HPC and JS repetitions with 20, 40, 60, 80, and 100% of their 1RM HPC. A linear position transducer was used to determine concentric duration and the percentage of the propulsive phase (P%) where barbell acceleration was greater than gravitational acceleration (i.e., a > −9.81 m/s2). Two 1 way repeated measures ANOVA were used to compare each variable across loads, whereas Hedge’s g effect sizes were used to examine the magnitude of the differences. Concentric duration ranged from 449.7 to 469.8 milliseconds and did not vary significantly between loads (p=0.253; g=0.20-0.39). The P% was 57.4±7.2%, 64.8±5.9%, 73.2±4.3%, 78.7±4.0%, and 80.3±3.5% when using 20, 40, 60, 80, and 100% 1RM HPC, respectively. P% produced during the 80 and 100% 1RM loads were significantly greater than those at 20, 40, and 60% 1RM (p<0.01, g=1.30-3.90). In addition, P% was significantly greater during 60% 1RM compared with both 20 and 40% 1RM (p<0.01, g=1.58-2.58) and 40% was greater than 20% 1RM (p=0.003, g=1.09). A braking phase was present during each load and, thus, a 1RM JS load was not established. Heavier loads may be needed to achieve a 100% propulsive phase when using this method.
Sweet, DK, Qiao, J, Rosbrook, P, and Pryor, JL. Load-velocity profiles before and after heated resistance exercise. J Strength Cond Res 38(6): 1019–1024, 2024—This study examined neuromuscular performance using load-velocity (L-V) profiles in men and women before and after resistance exercise (RE) in hot (HOT; 40° C) and temperate (TEMP; 21° C) environments. Sixteen ( f = 8, m = 8) resistance-trained individuals completed a single 70-minute whole-body high-volume load (6 exercises, 4 sets of 10 repetitions) RE bout in HOT and TEMP. Before and after RE, rectal temperature (T RE ), muscle temperature of the vastus lateralis (T VL ) and triceps brachii (T TB ), and an L-V profile for the deadlift and bench press were recorded. Thermoregulatory and L-V data were analyzed using separate 2-way repeated measures analysis of variances (ANOVAs; condition [hot, temperate] and time [pre, post]) with significance level set at p ≤ 0.05. Deadlift peak velocity was reduced at 60% 1 repetition maximum (1RM) after RE in HOT but not TEMP. Peak velocity of 40% 1RM bench press was lower in TEMP vs. HOT pre-RE ( p < 0.01). Peak velocity was decreased at all loads in the deadlift L-V profile after RE, regardless of condition. Despite elevated T RE (TEMP; 37.58 ± 0.35, HOT; 38.20 ± 0.39° C), T VL (TEMP; 35.24 ± 0.62, HOT; 37.92 ± 0.55° C), and T TB (TEMP; 35.05 ± 0.78, HOT; 38.00 ± 0.16° C) after RE in HOT vs. TEMP ( p < 0.01), RE in HOT did not broadly affect L-V profiles. This indicates heated resistance exercise can be performed with high-volume load and high ambient temperature with minimal performance impairment.
The aims of this study were to assess (i) the load–velocity relationship during the box squat exercise in women survivors of breast cancer, (ii) which velocity variable (mean velocity [MV], mean propulsive velocity [MPV], or peak velocity [PV]) shows stronger relationship with the relative load (%1RM), and (iii) which regression model (linear [LA] or polynomic [PA]) provides a greater fit for predicting the velocities associated with each %1RM. Nineteen women survivors of breast cancer (age: 53.2 ± 6.9 years, weight: 70.9 ± 13.1 kg, and height: 163.5 ± 7.4 cm) completed an incremental load test up to one‐repetition maximum in the box squat exercise. The MV, MPV, and the PV were measured during the concentric phase of each repetition with a linear velocity transducer. These measurements were analyzed by regression models using LA and PA. Strong correlations of MV with %1RM (R² = 0.903/0.904; the standard error of the estimate (SEE) = 0.05 m.s⁻¹ by LA/PA) and MPV (R² = 0.900; SEE = 0.06 m.s⁻¹ by LA and PA) were observed. In contrast, PV showed a weaker association with %1RM (R² = 0.704; SEE = 0.15 m.s⁻¹ by LA and PA). The MV and MPV of 1RM was 0.22 ± 0.04 m·s⁻¹, whereas the PV at 1RM was 0.63 ± 0.18 m.s⁻¹. These findings suggest that the use of MV to prescribe relative loads during resistance training, as well as LA and PA regression models, accurately predicted velocities for each %1RM. Assessing and prescribing resistance exercises during breast cancer rehabilitation can be facilitated through the monitoring of movement velocity.
The purpose of this study is to examine the effect of plyometric resistance training applied to the Turkish National Junior Men's Boxing Team during the European Championship preparation process. A total of 14 athletes from the Turkish National Junior Men's Boxing Team volunteered to participate in the study. The average age of the boxers was 17.57±1.04 years, the average height was 172.28±5.7 cm, the average weight was 72.14±2.9 kg, and the average body fat percentage was 20.47±1.15%. Participants engaged in a plyometric resistance training program prepared and scheduled by the researchers throughout the preparation camp. Various physical and biomotor parameters of all boxers (weight, BMI, body fat percentage, Squat, vertical jump, reaction time, grip strength, 5-meter speed, 10-meter speed, 40-meter speed, flexibility included) were measured at the beginning and end of the camp. Statistical analyses of all data were performed using the SPSS 22.0 statistical package program. Normal distribution analyses were conducted using the Shapiro-Wilk Test. Wilcoxon Test was used for the pre-test and post-test comparison of Body Mass Index and weight values, while the paired T-test statistic was used for the pre-test and post-test comparison of body fat percentage, Squat, vertical jump, reaction time, grip strength, 5-meter speed, 10-meter speed, 40-meter speed, and flexibility values. A significance value of p < 0.05 was accepted. Statistically significant changes were observed between pre- and post-camp changes. In conclusion, we suggest that a well-designed plyometric resistance training program can positively contribute to the physical and biomotor parameters of national junior male boxers before an important tournament during a preparation camp.
Velocity-based training (VBT) can help all people who participate in resistance training (RT) programs to improve/maintain health and physical fitness levels. VBT is a RT intervention that uses velocity feedback to prescribe and/or manipulate training load. Two new variables are adopted for prescribing the training load in VBT, one is the initial fastest repetition velocity in sets to set the load instead of %1RM, the other is the velocity loss threshold (VL) to terminate the set instead of the traditional fixed repetitions. VBT sessions relatively have lower volume and lower post-exercise fatigue, and this reason may encourage people to use it as a training method. In addition, VBT devices help coaches to predict optimal load and volume before each training session; so modified training variables result in a better adaptation. On the other hand, VBT devices are expensive and the dose-response relationship between velocity loss and neuromuscular adaptation is still not clear.
The purpose of this study was to investigate the reproducibility of findings derived from a new iso-inertial dynamometer during bench press (BP) and squat (SQ) and to provide descriptive data for recreational athletes. A position transducer and accelerometer were combined to assess velocity and power during free weight lifting exercises. Simulated movement with a pulley system revealed the excellent technical consistency of the dynamometer. Sixteen male subjects participated in the study. Iso-inertial tests consisted of lifting as fast as possible four different relative loads (35, 50, 70, 90% 1RM in BP and 45, 60, 75, 90% 1RM in SQ). The test was repeated one week later. Analysis of variance revealed no significant variation between sessions or trials. Reproducibility was better in velocity than in power, although it remained fairly good in both exercises (coefficients of variation [CV] never exceeding 10%) except for the time to peak power parameter. Descriptive data confirmed the classical force-velocity and force-power relationships for BP and SQ. In conclusion, this study demonstrated reliable measurements in BP and SQ iso-inertial exercises. Monitoring force-velocity and force-power relationships offers an original functional approach in strength training supervision.
The aim of this study was to investigate the kinematics, kinetics, and neural activation of the traditional bench press movement performed explosively and the explosive bench throw in which the barbell was projected from the hands. Seventeen male subjects completed three trials with a bar weight of 45% of the subject's previously determined 1RM. Performance was significantly higher during the throw movement compared to tile press for average velocity, peak velocity, average force, average power, and peak power. Average muscle activity during the concentric phase for pectoralis major, anterior deltoid, triceps brachii, and biceps brachii was higher for the throw condition. It was concluded that performing traditional press movements rapidly with light lends does not create ideal loading conditions for the neuromuscular system with regard to explosive strength production, especially in the final stages of the movement, because ballistic weight loading conditions where the resistance was accelerated throughout the movement resulted in a greater velocity of movement, force output, and EMG activity.
The performance of ten elite powerlifters were analyzed in a simulated competition environment using three-dimensional cinematography and surface electromyography while bench pressing approximately 80% of maximum, a maximal load, and an unsuccessful supramaximal attempt. The resultant moment arm (from the sagittal and transverse planes) of the weight about the shoulder axis decreased throughout the upward movement of the bar. The resultant moment arm of the weight about the elbow axis decreased throughout the initial portion of the ascent of the bar, recording a minimum value during the sticking region, and subsequently increased throughout the remainder of the ascent of the bar. The electromyograms produced by the prime mover muscles (sternal portion of pectoralis major, anterior deltoid, long head of triceps brachii) achieved maximal activation at the commencement of the ascent phase of the lift and maintained this level essentially unchanged throughout the upward movement of the bar. The sticking region, therefore, did not appear to be caused by an increase in the moment arm of the weight about the shoulder or elbow joints or by a minimization of muscular activity during this region. A possible mechanism which envisages the sticking region as a force-reduced transition phase between a strain energy-assisted acceleration phase and a mechanically advantageous maximum strength region is postulated.
Considerable debate exists as to whether the qualities of muscle function exist as general or specific physiological capacities. If there is a generality of muscle function then strong relationships would exist between various measures of function for the same muscle(s), independent of the test contraction, mode or velocity. The purpose of this study was to examine the relationship between isometric and dynamic measures of muscle function to determine the existence of generality or specificity. A group of 22 men, experienced in weight training, were tested for lower and upper body dynamic and isometric measures of strength and speed-strength. The changes in these measures consequent to a resistance training programme were also investigated. The results of this study indicated that whilst isometric and dynamic measures of strength did significantly correlate (r = 0.57-0.61), the relationship was below that required to denote statistical generality. More important, the changes in isometric and dynamic strength consequent to a dynamic heavy resistance training programme were unrelated (r = 0.12-0.15). Thus the mechanisms that contribute to enhanced dynamic strength appeared unrelated to the mechanisms that contribute to enhanced isometric strength. Measures of dynamic and isometric speed-strength were unrelated, as were the changes in these measures resulting from training. The results of this study demonstrated that a generality of muscle function did not exist and that modality specific results were observed. Consequently this study calls into question the validity of isometric tests to monitor dynamically induced training adaptations.
Although explosive power in lower-body movements has been extensively studied, there is a paucity of research examining such movements in the upper body. This study aimed to investigate the influence of load and the stretch shortening cycle (SSC) on the kinematics, kinetics, and muscle activation that occurs during maximal effort throws. A total of 17 male subjects performed SSC and concentric only (CO) bench throws using loads of 15%, 30%, 45%, 60%, 75%, 90% and 100% of their previously determined one repetition maximum bench press. The displacement, velocity, acceleration, force and power output as well as the electromyogram (EMG) from pectoralis major, anterior deltoid, and triceps brachii were recorded for each throw. The results were compared using multivariate analysis of variance with repeated measures. A criterion alpha level of P < or = 0.05 was used. Similar force velocity power relationships were determined for this multijoint upper-body movement as has been found for isolated muscles, single joint movements, and vertical jumping. The highest power output was produced at the 30% [563 (104) W] and 45% [560 (86) W] loads during the SSC throws. Force output increased as a function of load; however, even the lighter loads resulted in considerable force due to the high accelerations produced. Average velocity, average and peak force, and average and peak power output were significantly higher for the SSC throws compared to the CO throws. However, peak velocity and height thrown were not potentiated by performing the pre-stretch because the duration and range of movement allowed the ability of the muscle to generate force at high shortening velocities to dominate the resulting throw. As such, explosive movements involving longer concentric actions than experienced during brief SSC movements may be limited by the ability of the muscle to produce force during fast contraction velocities.
A great deal of literature has investigated the effects of various resistance training programmes on strength and power changes. Surprisingly, however, our understanding of the stimuli that affect adaptation still remains relatively unexplained. It is thought that strength and power adaptation is mediated by mechanical stimuli, that is the kinematics and kinetics associated with resistance exercise (e.g. forces, contraction duration, power and work), and their interaction with other hormonal and metabolic factors. However, the effect of different combinations of kinematic and kinetic variables and their contribution to adaptation is unclear. The mechanical response to single repetitions has been investigated by a number of researchers; however, it seems problematic to extrapolate the findings of this type of research to the responses associated with a typical resistance training session. That is, resistance training is typified by multiple repetitions, sets and exercises, rest periods of varying durations and different movement techniques (e.g. controlled and explosive). Understanding the mechanical stimuli afforded by such loading schemes would intuitively lead to a better appreciation of how various mechanical stimuli affect adaptation. It will be evident throughout this article that very little research has adopted such an approach; hence our understanding in this area remains rudimentary at best. One should therefore remain cognizant of the limitations that exist in the interpretation of research in this field. We contend that strength and power research needs to adopt a set kinematic and kinetic analysis to improve our understanding of how to optimise strength and power.
The endocrine system plays an important role in strength and power development by mediating the remodelling of muscle protein. Resistance training scheme design regulates muscle protein turnover by modifying the anabolic (testosterone, growth hormone) and catabolic (cortisol) responses to a workout. Although resistance exercise increases the concentrations of insulin-like growth factor 1 in blood following exercise, the effect of scheme design is less clear, most likely due to the different release mechanisms of this growth factor (liver vs muscle). Insulin is non-responsive to the exercise stimulus, but in the presence of appropriate nutritional intake, elevated blood insulin levels combined with resistance exercise promotes protein anabolism. Factors such as sex, age, training status and nutrition also impact upon the acute hormonal environment and, hence, the adaptive response to resistance training. However, gaps within research, as well as inconsistent findings, limit our understanding of the endocrine contribution to adaptation. Research interpretation is also difficult due to problems with experimental design (e.g. sampling errors) and various other issues (e.g. hormone rhythms, biological fluid examined). In addition to the hormonal responses to resistance exercise, the contribution of other acute training factors, particularly those relating to the mechanical stimulus (e.g. forces, work, time under tension) must also be appreciated. Enhancing our understanding in these areas would also improve the prescription of resistance training for stimulating strength and power adaptation.
The aim of this study was to investigate the ability of isoinertial assessment to monitor training effects. Both parametric and curve analysis of the results were used to underline the specificity of maximal strength and maximal velocity resistance training methods.
Twenty-four untrained subjects were randomly assigned into three groups: a maximal strength-training group (heavy loads: 80% to 98% of the one repetition maximum [1-RM]), a maximal velocity-training group (light loads: 25% to 50% of 1-RM) and a control group. All the subjects were tested in bench press exercises before and after the 6-week training period. An isoinertial dynamometer was used to assess velocity and power at four increasing loads: 35%, 50%, 70% and 95% of the 1-RM load. Post-test protocol also included a trial at 105% of the 1-RM load.
Isoinertial assessment demonstrated for both training groups significant gains at each load. Some specific adaptations appeared: strength training presented a greater increase for average power (+49%, P<0.001) and average velocity (+48%, P<0.001) at 95% of 1-RM, while velocity training emerged as a more effective way to improve performance at 35% and 50% of 1-RM (+11 to 22%) in comparison with strength training (+7 to 12%). The analysis of power and velocity curves specified that strength training enhanced performance earlier in the movement, while velocity training extended the propulsive action at the end of movement.
The original combination of parametric and curve isoinertial assessment appears to be a relevant method for monitoring specific training effects. The complementarity of both strength and velocity training programmes underlined in this study could lead to practical applications in profiling training programmes.
The purpose of this study was to investigate the force-velocity response of the neuromuscular system to a variety of concentric only, stretch-shorten cycle, and ballistic bench press movements. Twenty-seven men of an athletic background (21.9 +/- 3.1 years, 89.0 +/- 12.5 kg, 86.3 +/- 13.6 kg 1 repetition maximum [1RM]) performed 4 types of bench presses, concentric only, concentric throw, rebound, and rebound throw, across loads of 30-80% 1RM. Average force output was unaffected by the technique used across all loads. Greater force output was recorded using higher loading intensities. The use of rebound was found to produce greater average velocities (12.3% higher mean across loads) and peak forces (14.1% higher mean across loads). Throw or ballistic training generated greater velocities across all loads (4.4% higher average velocity and 6.7% higher peak velocity), and acceleration-deceleration profiles provided greater movement pattern specificity. However, the movement velocities (0.69-1.68 m.s(-1)) associated with the loads used in this study did not approach actual movement velocities associated with functional performance. Suggestions were made as to how these findings may be applied to improve strength, power, and functional performance.
The purposes of this investigation were to assess whether maximal isoinertial (triceps pushdown [TP] and triceps extension [TE]), isometric and isokinetic (1.04, 2.08, 3.14, 4.16, and 5.20 rad·s-1) forearm extension strength measures: 1) presented statistical generality when they were correlated prior to and following 4, 8, and 12 wk of resistance training; 2) were similarly affected by training; and 3) presented statistical generality when their changes as a consequence of training were intercorrelated. Fifteen men (11 experimental and 4 controls) without a history of resistance training participated in the study. Training involved four sets of 8-12 repetitions, each followed by 90-s recovery, at 70-75% one repetition maximum (1RM), three times a week, for 12 wk. Training incorporated the TP, close-grip bench press, and triceps kickback exercises. Prior to and after 4, 8, and 12 wk of training, the intercorrelations among the TP, isometric, and isokinetic indices almost always achieved statistical generality (i.e., r2 > 0.5). It was concluded that the strength measures generally discriminated similarly between subjects. However, the sensitivity of the strength measures to the effects of training were dissimilar. While all strength indices increased with the training, the timing(isoinertial prior to isometric and isokinetic adaptations) and magnitude(TP>TE> isometric>isokinetic) of these adaptations varied greatly. None of the intercorrelations between changes in the strength indices achieved statistical generality. Furthermore, factor (F)-analyses on these changes indicated that in the initial and later stages of training, there were three and four discrete factors, respectively, accounting for strength development. These factors were thought to reflect differential effects of training on the structural, neural (including learning), and mechanical mechanisms underpinning each strength index. Possible applications of this research design in better understanding strength development were also canvassed.
The purpose of the study was to evaluate selected parameters describing performance characteristics of a free-weight and isokinetic bench press. A secondary purpose was an attempt to clarify the technique requirements essential for a successful lift. Parameters describing the free-weight condition were generated from cinematographic data (150 fps) for five trials each at 90 and 75% of the subject's maximal performance (1RM). Isokinetic data were obtained from an instrumented Cybex Power Bench Press at two speeds corresponding to the average speeds for the free-weight conditions. Despite differences, accommodation appeared to occur for both methods when the lifts were performed maximally. A "sticking region" was defined as the portion of the free-weight activity when the subjects' force application was less than the weight of the bar. No significant difference (P less than 0.05) was observed between the 90% 1RM (26.02%) and 75% 1RM (26.94%) mean relative time values for these regions. For the Cybex device, the percentage of the activity which was isokinetic was longer for the slower speeds of rotation (0.47 rad X s-1 = 70%) and steadily decreased until the movement was only 50% isokinetic at 1.74 rad X s-1. The observed relationships between applied force-time data along with anatomical considerations suggest an ideal technique for the lift.
The purpose of this investigation was to develop a new test of muscle function, termed the iso-inertial force-mass relationship, and to determine its relationship to dynamic physical performance in comparison to an isometric test. A group of 13 trained subjects performed an isometric, and a series of iso-inertial maximal upper body tests, in a bench press movement at loads of 30%, 60%, 100% (concentric) and 100%, 130% and 150% (eccentric) of maximum. Vertical forces exerted throughout the movement were recorded by a force plate. In addition, the subjects performed the following three performance tests: a maximal bench press, a seated shotput, and two drop bench-press throws from a height of 0.25 m, with loads of 10 kg and 30% of maximum. Correlation analysis demonstrated that in each instance the iso-inertial force mass tests were the best predictors of performance (r = 0.78-0.88) with both contraction type and mass specific effects apparent. Maximal isometric force and rate of force development were significantly related to some performance variables (r = 0.22-0.78). However, for all the performance movements assessed, the iso-inertial test modality recorded the highest relationship to performance. The difference in the relationship between performance and iso-inertial and isometric test modalities was particularly evident in the light load dynamic performance of the seated shotput (r = 0.86 vs r = 0.38, respectively). These results are explained in part by the neural and mechanical differences between iso-inertial and isometric muscle actions and their respective specificity to dynamic physical performance.
The purposes of this investigation were to assess whether maximal isoinertial (triceps pushdown [TP] and triceps extension [TE]), isometric and isokinetic (1.04, 2.08, 3.14, 4.16, and 5.20 rad.s-1) forearm extension strength measures: 1) presented statistical generality when they were correlated prior to and following 4, 8, and 12 wk of resistance training; 2) were similarly affected by training; and 3) presented statistical generality when their changes as a consequence of training were intercorrelated. Fifteen men (11 experimental and 4 controls) without a history of resistance training participated in the study. Training involved four sets of 8-12 repetitions, each followed by 90-s recovery, at 70-75% one repetition maximum (1RM), three times a week, for 12 wk. Training incorporated the TP, close-grip bench press, and triceps kickback exercises. Prior to and after 4, 8, and 12 wk of training, the intercorrelations among the TP, isometric, and isokinetic indices almost always achieved statistical generality (i.e., r2 > 0.5). It was concluded that the strength measures generally discriminated similarly between subjects. However, the sensitivity of the strength measures to the effects of training were dissimilar. While all strength indices increased with the training, the timing (isoinertial prior to isometric and isokinetic adaptations) and magnitude (TP > TE > isometric > isokinetic) of the adaptations varied greatly. None of the intercorrelations between changes in the strength indices achieved statistical generality. Furthermore, factor (F)-analyses on these changes indicated that in the initial and later stages of training, there were three and four discrete factors, respectively, accounting for strength development. These factors were thought to reflect differential effects of training on the structural, neural (including learning), and mechanical mechanisms underpinning each strength index. Possible applications of this research design in better understanding strength development were also canvassed.
This investigation compared the relationship of isokinetic and isoinertial tests of muscular function to dynamic upper body performances. The electromiyographic activity of each of the tests of muscular function, as recorded by surface electrodes, were examined to determine whether neural differences underlie the ability of the test to relate to performance. Twenty four subjects performed isokinetic and isoinertial tests of muscular function in a bench press movement. The isokinetic tests were performed at velocities of 60, 90 and 120 deg/s while the isoinertial tests were performed at loads of 30%, 60% and 130% of the one repetition maximum. Subjects also performed the following tests of dynamic performance: a maximum one repetition bench press (1 RM), a seated shotput throw and two drop bench press throws from a height of 0.25 m at various loads. Forces/torques, displacement and electromyographic data were recorded from the isoinertial and isokinetic tests. Both the isoinertial and isokinetic parameters were related to the various measures of upper body performance (r = 0.33-0.94), however, neither was superior at predicting performance. Further, the relationship between the tests of muscular function were consistently high (r = 0.75-0.88). This was the case, even though the magnitude of the EMG signals were significantly higher in the isoinertial, as compared to the isokinetic tests. It is postulated that structural considerations, such as a specific testing position, rather than neural factors, underlie the observed results. These results support previous research which has reported the existence of a generality of strength across dynamic testing modalities.
Muscle cross-sectional area of the quadriceps femoris (CSAQF), maximal isometric strength (handgrip test and unilateral knee extension/flexion), the shape of isometric force-time curves, and power-load curves during concentric and stretch-shortening cycle (SSC) actions with loads ranging from 15 to 70% of one repetition maximum half-squat (1RMHS) and bench-press (1RMBP) were examined in 26 middle-aged men in the 40-year-old (M40) (mean age 42, range 35-46) and 21 elderly men in the 65-year-old age group (M65) (mean age 65, range 60-74). Maximal bilateral concentric (1RMHS and 1RMBP), unilateral knee extension (isometric; MIFKE and concentric; 1RMKE) strength and muscle CSA in M65 were lower (P < 0.001) than in M40. The individual values of the CSAQF correlated with the individual values of maximal concentric 1RMHS, 1RMKE and MIFKE in M65, while the corresponding correlations were lower in M40. The maximal MIFKE value per CSA of 4.54 +/- 0.7 N m cm-2 in M40 was greater (P < 0. 05-0.01) than that of 4.02 +/- 0.7 N m cm-2 recorded in M65. The maximal rate of force development of the knee extensors and flexors in M65 was lower (P < 0.01-0.001) and the heights in squat and counter-movement jumps as much as 27-29% lower (P < 0.001) than those recorded in M40. M65 showed lower (P < 0.001) concentric power values for both upper and lower extremity performances than those recorded for M40. Maximal power output was maximized at the 30-45% loads for the upper extremity and at the 60-70% loads for the lower extremity extensors in both age groups. Muscle activation of the antagonists was significantly higher (P < 0.01-0.001) during the isometric and dynamic knee extension actions in M65 than in M40. The present results support a general concept that parallel declines in muscle mass and maximal strength take place with increasing age, although loss of strength may vary in both lower and upper extremity muscles in relation to the type of action and that ageing may also lead to a decrease in voluntary neural drive to the muscles. Explosive strength and power seem to decrease with increasing age even more than maximal isometric strength in both actions but power was maximized at the 30-45% loads for the upper and at the 60-70% loads for the lower extremity action in both age groups. High antagonist muscle activity may limit the full movement efficiency depending on the type of muscle action, testing conditions and the velocity and/or the time duration of the action, especially in the elderly.
The influence of maximal strength, as measured by the maximal load lifted for one repetition (1RM), on power production in the initial 200 ms of the concentric phase for both rebound and nonrebound movements was investigated. We also investigated the effect of external load upon this relationship.
Twenty-seven male subjects (21.9 +/- 3.1 yr, 89.0 +/- 12.5 kg) were separated by previously determined bench press IRM into high (100.88 +/- 7.24 kg) and low (72 +/- 6.61 kg) RM groups. Concentric only bench presses and rebound bench presses were compared between and within groups to note the effect of RM across external loads of 40%, 60%, and 80% 1RM, on instantaneous, mean, and peak power output.
The results of this study clearly indicated the enhancement of concentric motion by prior eccentric muscle action (336-1332% enhancement in the first 20 ms). Possessing a high RM augmented power production in the initial 200 ms of stretch-shorten cycle activity, across all the external resistances tested (P < 0.05). The temporal characteristics of this enhancement, however, differed across loads. That is, 80% IRM loading showed a later time to peak enhancement (80 ms vs 20 ms). Interestingly, the influence of RM on concentric only motion in the initial 200 ms across the external resistances tested was found to be nonsignificant.
The results suggest that the role of maximal strength during initial power production between concentric and stretch-shorten cycle activity differs, which has important implications for the training of athletes.
The influence of contraction type and movement type on power output of the upper body musculature was investigated across loads of 30-80% 1RM. Twenty seven males (21.9+/-3.1 years, 89.0+/-12.5 kg, 86.32+/-13.66 kg 1RM) of an athletic background but with no weight training experience in the previous six months volunteered for the study. The results were compared using multivariate analysis of variance with repeated measures (p< or =0.05). It was found that the combinations of load, movement and contraction type affected mean and peak power in different capacities. Mean power output for rebound motion was 11.7% greater than concentric only motion. The effect of the rebound was to produce greater peak accelerations (38.5%--mean across loads), greater initial force and peak forces (14.1%--mean across loads) and early termination of the concentric phase. Peak power output was most influenced by the ability to release the bar, the greater mean velocities across all loads (4.4% average velocity and 6.7% peak velocity) attained using such a technique appeared the dominating influence. Loads of 50-70% 1RM were found to maximize mean and peak power. Loading the neuromuscular system to maximize mean or peak power output necessitates an understanding of the force-velocity characteristics of the training movement and the requirements of the individual related to the athletic performance and their training status.
Three studies that used rugby league players experienced in power training methods as subjects were performed to investigate the resistance (percentage of 1 repetition maximum [1RM]) that maximized the average mechanical power output (Pmax) during the jump squat exercise. Maximum strength was assessed via 1RM (studies 2 and 3) or 3RM (study 1) during the full-squat exercise. Pmax was assessed during barbell jump squats, using resistances of 40, 60, 80, and 100 kg within the Plyometric Power System. All studies found that power output was maximized by resistances averaging circa 85-95 kg, representing 55-59% of 1RM full-squat strength. However, loads in the range of 47-63% of 1RM were often similarly effective in maximizing power output. The results of this investigation suggest that athletes specifically trained via both maximal strength and power training methods may generate their maximal power outputs at higher percentages of 1RM than those previously reported for solely strength-trained athletes and that there would appear to be an effective range of resistances for maximizing power output.
Levels of upper-body strength and power can distinguish between athletes of different levels in a number of sports. The purpose of this investigation was to compare the maximum upper-body strength and power of 22 professional National Rugby League (NRL) and 27 state- and city-league, college-aged (SRL) rugby league players. All players were from the same football club and had undergone the same preseason strength and power training program for the 8 weeks prior to testing. Maximum strength was assessed by a 1 repetition maximum bench press (1RM BP). Maximum power (Pmax) and power output with loads of 40, 50, 60, 70, and 80 kg (P40, P50, P60, P70, and P80) were assessed during BP throws using the plyometric power system (PPS). Despite no differences in body mass or height, the NRL players were significantly stronger and more powerful in every variable measured. Furthermore, the differences in power output between groups became more pronounced with increasing barbell loads. Overall strength and power were highly related (r = 0.82); however, the relationship between these variables was somewhat less in the stronger NRL group (NRL r = 0.58, SRL r = 0.85). The percentage 1RM which maximized power output was also significantly lower for the NRL group as well as for stronger subgroups within each group. The results suggest that maximum strength largely influences power output; however, once a strength plateau has been reached, the changing training emphasis toward power training or the negative effects of high-volume conditioning training may alter the extent of the relationship.
The power output generated with different barbell loads and which resistance generated the maximum mechanical power output (Pmax) during explosive bench press-type throws (BT) in a smith machine device were investigated in power-trained athletes. Thirty-one rugby league players were tested for 1 repetition maximum (1RM) free-weight bench press strength (1RM BP). Maximal power output was assessed by the Plyometric Power System during BT using resistances of 40, 50, 60, 70, and 80 kg (BT P40, BT P50, BT P60, BT P70, and BT P80). It was found that BT Pmax occurred with resistance of 70.1 +/- 7.9 kg, representing 55 +/- 5.3% of 1RM BP of 129.7 +/- 14.3 kg. The power output with all loads except the BT P70 were different from the BT Pmax. The BT P70 and BT P80 were not different from each other. Furthermore, the BT P60 and BT P80 were not different from each other. This suggests that although resistances of 55% 1RM BP may maximize power output during explosive BT, loads in the range of 46-62% also allow for high power outputs. Resistances of 31-45% of 1RM BP resulted in significantly lower power outputs. Compared with previous research of BT in strength-trained athletes, the results of this investigation suggest that power-trained athletes may generate their Pmax at higher percentages of 1RM.
The purpose of this study was to evaluate the use of traditional resistance training equipment in the measurement of muscular power. This was accomplished by measuring the velocity of movement through a measured distance during maximal effort lifts using a Smith rack. The reliability of the method was established using 10 male volunteers who performed both bench press and squat exercises in a Smith rack. Maximal power output was determined at 30, 40, 50, 60, 70, 80, and 90% of the subject's 1 repetition maximum (1RM). Test-retest power values were not statistically different. Another 15 male volunteers who had previous muscle biopsy data from the vastus lateralis muscle performed the same maximal power output evaluation. There were no significant relationships between peak power outputs and fiber-type expressions when linear regressions were performed. The power curve produced by graphing power output vs. the percentage of 1RM indicates that peak power output occurs between 50 and 70% of 1RM for the squat and between 40 and 60% of 1RM for the bench press. These data indicate that this method of evaluation of muscle power is reliable, although it is not predictive of muscle fiber-type percentages.
Maximal concentric one repetition maximum half-squat (1RM(HS)), bench-press (1RM(BP)), power-load curves during concentric actions with loads ranging from 30% to 100% of 1RM(HS) and 1RM(BP)were examined in 70 male subjects divided into five groups: weightlifters (WL, n=11), handball players (HP, n=19), amateur road cyclists (RC, n=18), middle-distance runners (MDR, n=10) and age-matched control subjects (C, n=12). The 1RM(HS)values in WL, HP and RC were 50%, 29% and 28% greater, respectively, ( P<0.001-0.01) than those recorded for MDR and C. The half-squat average power outputs at all loads examined (from 30% to 100%) in WL and HP ( P<0.001 at 45% and 60% with HP) were higher ( P<0.05-0.001) than those in MDR, RC and C. Average power output at the load of 30% of 1RM(HS) in RC was higher ( P<0.05) than that recorded in MDR and C. Maximal power output was produced at the load of 60% for HP, MDR and C, and at the load of 45% for WL and RC. The 1RM(BP) in WL was larger ( P<0.05) than those recorded in HP, RC, MDR and C. In the bench press, average muscle power outputs in WL and HP were higher ( P<0.05-0.001) than those in MDR, RC and C, and were maximized at a load of 30% of 1RM for WL and HP, and at 45% for RC, MDR and C. In addition, the velocities that elicited the maximal power in the lower extremities were lower ( approximately 0.75 m.s(-1)) than those occurring in the upper extremities ( approximately 1 m.s(-1)). The data suggest that the magnitude of the sport-related differences in strength and/or muscle power output may be explained in part by differences in muscle cross-sectional area, fibre type distribution and in the muscle mechanics of the upper and lower limbs as well as by training background.
The purpose of this study was to investigate the force-velocity response of the neuromuscular system to a variety of concentric only, stretch-shorten cycle, and ballistic bench press movements. Twenty-seven men of an athletic background (21.9 +/- 3.1 years, 89.0 +/- 12.5 kg, 86.3 +/- 13.6 kg 1 repetition maximum [1RM]) performed 4 types of bench presses, concentric only, concentric throw, rebound, and rebound throw, across loads of 30-80% 1RM. Average force output was unaffected by the technique used across all loads. Greater force output was recorded using higher loading intensities. The use of rebound was found to produce greater average velocities (12.3% higher mean across loads) and peak forces (14.1% higher mean across loads). Throw or ballistic training generated greater velocities across all loads (4.4% higher average velocity and 6.7% higher peak velocity), and acceleration-deceleration profiles provided greater movement pattern specificity. However, the movement velocities (0.69-1.68 m.s(-1)) associated with the loads used in this study did not approach actual movement velocities associated with functional performance. Suggestions were made as to how these findings may be applied to improve strength, power, and functional performance.
The ability to optimise muscular power output is considered fundamental to successful performance of many athletic and sporting activities. Consequently, a great deal of research has investigated methods to improve power output and its transference to athletic performance. One issue that makes comparisons between studies difficult is the different modes of dynamometry (isometric, isokinetic and isoinertial) used to measure strength and power. However, it is recognised that isokinetic and isometric assessment bear little resemblance to the accelerative/decelerative motion implicit in limb movement during resistance training and sporting performance. Furthermore, most people who train to increase power would have limited or no access to isometric and/or isokinetic dynamometry. It is for these reasons and for the sake of brevity that the findings of isoinertial (constant gravitational load) research will provide the focus of much of the discussion in this review.
One variable that is considered important in increasing power and performance in explosive tasks such as running and jumping is the training load that maximises the mechanical power output (Pmax) of muscle. However, there are discrepancies in the research as to which load maximises power output during various resistance exercises and whether training at Pmax improves functional performance is debatable. There is also some evidence suggesting that Pmax is affected by the training status of the individuals; however, other strength variables could quite possibly be of greater importance for improving functional performance. If Pmax is found to be important in improving athletic performance, then each individual’s Pmax needs to be determined and they then train at this load. The predilection of research to train all subjects at one load (e.g. 30% one repetition maximum [1RM]) is fundamentally flawed due to inter-individual Pmax differences, which may be ascribed to factors such as training status (strength level) and the exercise (muscle groups) used. Pmax needs to be constantly monitored and adjusted as research suggests that it is transient. In terms of training studies, experienced subjects should be used, volume equated and the outcome measures clearly defined and measured (i.e. mean power and/or peak power). Sport scientists are urged to formulate research designs that result in meaningful and practical information that assists coaches and strength and conditioning practitioners in the development of their athletes.
The influence of various loads on power output in the jump squat (JS), squat (S), and power clean (PC) was examined to determine the load that maximizes power output in each lift.
Twelve Division I male athletes participated in four testing sessions. The first session involved performing one-repetition maximums (1RM) in the S and PC, followed by three randomized testing sessions involving either the JS, S, or PC. Peak force, velocity, and power were calculated across loads of 0, 12, 27, 42, 56, 71, and 85% of each subject's 1RM in the JS and S and at 10% intervals from 30 to 90% of each subject's 1RM in the PC.
The optimal load for the JS was 0% of 1RM; absolute peak power was significantly lower from the optimal load at 42, 56, 71, and 85% of 1RM (P < or = 0.05), whereas peak power relative to body mass was significantly lower at 27% of 1RM in addition to 42, 56, 71, and 85% of 1RM. Peak power in the S was maximized at 56% of 1RM; however, power was not significantly different across the loading spectrum. The optimal load in the PC occurred at 80% of 1RM. Relative peak power at 80% of 1RM was significantly different from the 30 and 40% of 1RM.
This investigation indicates that the optimal load for maximal power output occurs at various percentages of 1RM in the JS, S, and PC.
The objective of this investigation was to examine the influence of body mass in the calculation of power and the subsequent effect on the load-power relationship in the jump squat, squat, and power clean. Twelve Division I male athletes were evaluated on their performance across various intensities in all the 3 lifts. Power output was calculated using 3 separate techniques: (a) including the contribution of body mass in force output (IBM), (b) including the contribution of the mass of body less the mass of the shanks and feet in force output (IBMS), and (c) excluding the contribution of body mass in force output (EBM). Peak power, peak power relative to body mass, and peak force calculated using EBM were significantly (p < or = 0.05) lower than outputs calculated with IBM and IBMS. The load that maximized power output was unchanged between the 3 techniques in the jump squat (0% 1 repetition maximum [1RM]) and power clean (80% 1RM) but was shifted from 56% (IBM and IBMS) to 71% 1RM (EBM) in the squat. Across all 3 movements, the shape of the load-power curve was affected when derived via the EBM method as a result of the underrepresentation of power output at light loads. This was due to the majority of the load being neglected when the mass of the body was removed from the system mass used in the calculation of force. This study indicates that not only is the actual power output significantly lower when body mass is excluded from the force output of a lower body movement, but the load-power relationship is altered as well. Therefore, it is imperative that the mass of the individual being tested is incorporated into the calculation of force used to determine power output during lower-body movements.
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