Article

Estimation of Relative Load From Bar Velocity in the Full Back Squat Exercise

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Abstract

The use of bar velocity to estimate relative load in the back squat exercise was examined. Eighty strength-trained men performed a progressive loading test to determine their one-repetition maximum (1RM) and load-velocity relationship. Mean (MV), mean propulsive (MPV) and peak (PV) velocity measures of the concentric phase were analyzed. Both MV and MPV showed a very close relationship to %1RM (R2 = 0.96), whereas a weaker association (R2 = 0.79) and larger SEE (0.14 vs. 0.06 m•s-1) was found for PV. Prediction equations to estimate load from velocity were obtained. When dividing the sample into three groups of different relative strength (1RM/body mass), no differences were found between groups for the MPV attained against each %1RM. MV attained with the 1RM was 0.32 ± 0.03 m•s-1. The propulsive phase accounted for 82% of concentric duration at 40% 1RM, and progressively increased until reaching 100% at 1RM. Provided that repetitions are performed at maximal intended velocity, a good estimation of load (%1RM) can be obtained from mean velocity as soon as the first repetition is completed. This finding provides an alternative to the often demanding, time-consuming and interfering 1RM or nRM tests and allows to implement a velocity-based resistance training approach.

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... Another interesting focus of study would be to examine what happens when maintaining the same multimodal exercises in two FFT programs while modifying rest intervals, in which participants carry out the same number of repetitions with the same workload (same absolute training volume and absolute load but different density of training due to the different rest intervals). This could give rise to two situations: (1) Relative work intensities could differ as an absolute workload in one individual could represent different relative intensities depending on the velocity reached [13][14][15][16]. That is, with the introduction rest periods, repetitions could be performed at a higher velocity, representing a lower relative intensity for that absolute load. ...
... These variables were measured during the CMJ on a portable 92 × 92 × 12.5 cm force platform (Quattro Jump model 9290AD; Kistler Instruments, Winterthur, Switzerland). Jump height and power losses during an exercise session have been defined as indicators of mechanical and neuromuscular fatigue of the leg muscles [15]. Another variable recorded in this test was total CMJ duration. ...
... Thus, we were able to observe that many participants did not take breaks, or took minimal breaks (a few seconds) between repetitions. Several studies have shown that for a given absolute load (kg), subjects can show different velocities, meaning that this load can represent a different relative intensity (%) depending on the velocity reached by each subject in each exercise [13][14][15][16]. Thus, it could be that when the participants executed FFTstandard, because of the scarce rest intervals taken, execution velocities were reduced. ...
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Background: Functional Fitness Training (FFT) is a new exercise modality prioritizing functional multi-joint movements executed at high intensity as a circuit. Objective: To examine the impacts of introducing rest intervals in a FFT workout compared to "rounds for time" (RFT) FFT. Materials and Methods: Participants were 25 resistance-trained adults who completed two FFT workouts 1 week apart. The study design was crossover such that in a given session half the participants completed the standard and the other half the adapted FFT (FFTadapted). The workouts consisted of the same exercises (circuit of four rounds of exercises), but one (FFTadapted) included preset rest intervals (three sets of 1 min after each completed round). Before and after the workouts, countermovement jump ability and blood lactate were measured. Heart rate (HR) and ratings of perceived exertion (RPE) were measured post-exercise. Results: For both the standard and adapted protocols, mean HR was 90% age-predicted maximum. Final RPE was also similar for both workouts (~15-15.5) and indicated a "hard" work intensity. Both FFTs took the same time to complete (~13 min). Furthermore, no significant differences were observed in jump ability between FFTs. In contrast, lactate (15.11 ± 3.64 vs. 13.48 ± 3.64 mmol•L −1 , p < 0.05), measured 3 min post-exercise, was significantly lower in FFTadapted. Conclusions: In FFTadapted, there was a significant reduction in RPE and blood lactate concentrations after exercise, while there were no significant differences in either HR or jumping ability, compared to a FFT workout in RFT methodology.
... The participants were instructed to lower the bar slowly (~0.70-0.50 m·s −1 ) [38] and in a controlled motion until reaching 1 cm from the upper part of the xiphoid process. They were then told to stop for approximately 1.5 s [35] until the evaluator instructed them to extend their arms at maximum velocity without raising their trunk or shoulders from the bench. ...
... For the full squat, the subjects started in an upright position with their knees and hips extended. They kept their feet at the same distance as the width of their shoulders and the bar on the trapeziums at the level of the acromion [38]. This position was carefully verified so that it could be reproduced in subsequent series. ...
... Participants descended in a controlled manner at an average velocity of~0.70-0.50 m·s −1 until reaching a fibula-femoral flexion angle of 35-40 • along the sagittal plane [38] to achieve a full squat [40]. This was measured with a goniometer (Nexgen Ergonomics, Point Claire, QC, Canada). ...
Article
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The purpose of this study was to determine the mean propulsive velocity (MVP) at various percentages of one repetition maximum (1RM) in the full squat and chest press exercises. A total of 96 young women and 256 young men (recreational athletes) performed an incremental test (50–60–70–80% 1RM) comprising the bench press and full squat exercises in two different sessions. The individual load and velocity ratios were established through the MPV. Data were analyzed using SPSS software version 25.0, with the significance level set at 5%. The following findings were revealed: highly linear load-velocity relationships in the group of women (r = 0.806 in the squat, and r = 0.872 in the bench press) and in the group of men (r = 0.832 and r = 0.880, respectively); significant differences (p < 0.001) in the MPV at 50–70–80% 1RM between the bench press and the full squat in men and at 70–80% 1RM in women; and a high variability in the MPV (11.49% to 22.63) in the bench press and full squat (11.58% to 25.15%) was observed in women and men (11.31% to 21.06%, and 9.26% to 24.2%) at the different percentages of 1RM evaluated. These results suggest that the load-velocity ratio in non-strength-trained subjects should be determined individually to more precisely establish the relative load to be used in a full squat and bench press training program.
... A detailed description of the SQ testing protocol has been provided elsewhere [16]. Testing was performed on a Smith machine (Multipower Fitness Line, Peroga, Murcia, Spain). ...
... All rights reserved. ended when the attained concentric MPV was slower than ~0.60 m·s -1 , which corresponds to ~85% 1RM in the SQ [16]. Three repetitions were performed for light (MPV ≥ 1.10 m·s -1 ), two for medium (1.10 m·s -1 > MPV ≥ 0.80 m·s -1 ), and only one for the heaviest (MPV < 0.80 m·s -1 ) loads. ...
... The 1RM was individually estimated for each participant from the MPV value attained against the heaviest load lifted in the progressive test, as follows: (100 · load)/(-5.961 · MPV 2 − 50.71 · MPV + 117) [16]. Table 1. ...
Article
This study aimed to analyze the acute mechanical, metabolic and EMG response to five resistance exercise protocols (REP) in the full squat (SQ) exercise performed with 2 velocity conditions: maximal intended velocity (MaxV) vs. half-maximal velocity (HalfV). Eleven resistance-trained men performed 10 REP (5 with each velocity conditions) in random order (72-96 h apart). The REP consisted of 3 sets of 8-3 repetitions against 45-65% 1RM. The percent change in countermovement jump (CMJ) height, velocity attained with the load that elicited a ~1.00 m·s-1 (V1-load), surface EMG variables and blood lactate concentration were assessed pre- vs. post-exercise protocols. MaxV resulted in greater percent changes (Δ: 12-25%) and intra-condition effect sizes (ES: 0.76-4.84) in loss of V1-load and CMJ height compared to HalfV (Δ: 10-16%; ES: 0.65-3.90) following all REP. In addition, MaxV showed higher post-exercise lactate concentration than HalfV (ES: 0.46-0.83; p<0.05). For EMG variables, only the Dimitrov index resulted in relevant changes after each REP, with MaxV showing greater magnitude of changes (23-38%) than HalfV (12-25%) across all REP. These results suggest that voluntary movement velocity is a key aspect to consider since it clearly determines the overall training intensity during resistance exercise.
... A detailed description of the SQ testing protocol has been provided elsewhere. 35 The participants performed the SQ Note: ...
... The initial load was set at 30 kg for all participants and was gradually increased by 10 kg until the mean propulsive velocity (MPV) was lower than ~0.60 m·s −1 , which corresponds to ~85% 1RM in the SQ. 35 During the test, three repetitions were executed for light (MPV>1.10 m·s −1 ), two for medium (1.10 m·s −1 >MPV>0.80 ...
... Relative load (% 1RM) for each traininor each training session was determined from theg session was determined from the load-velocity relationship for the SQ. 35 Thus, a target velocity to be attained in the first (usually the fastest) repetition of the first set of each training session was used as an estimation of load, as follows: ~1.08 m·s −1 (~55% 1RM), ~1.00 m·s −1 (~60% 1RM), ~0.92 m·s −1 (~65% 1RM), and ~0.84 m·s −1 (~70% 1RM). Consequently, before starting the first set, adjustments in the proposed load (kg) were made when needed so that the velocity of the first repetition matched the scheduled target MPV (±0.03 m·s −1 ). ...
Article
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This study aimed to compare the effects of three resistance training (RT) programs differing in the magnitude of velocity loss (VL) allowed in each exercise set: 10%, 30% or 45% on changes in strength, vertical jump, sprint performance and EMG variables. Thirty‐three young men were randomly assigned into three experimental groups (VL10%, VL30% and VL45%; n=11 each) that performed a velocity‐based RT program for 8 weeks using only the full‐squat exercise (SQ). Training load (55‐70% 1RM), frequency (2 sessions/week), number of sets (3) and inter‐set recovery (4 min) were identical for all groups. Running sprint (20 m), countermovement jump (CMJ), 1RM, muscle endurance and EMG during SQ were assessed pre‐ and post‐training. All groups showed significantly (VL10%: 6.4‐58.6%; VL30%: 4.5‐66.2%; VL45%: 1.8‐52.1%; p<0.05‐0.001) improvements in muscle strength and muscle endurance. However, a significant group×time interaction (p<0.05) was observed in CMJ, with VL10% showing greater increments (11.9%) than VL30% and VL45%. In addition, VL10% resulted in greater percent change in sprint performance than the other two groups (VL10%: ‐2.4%; VL30%: ‐1.8%; VL45%: ‐0.5%). No significant changes in EMG variables were observed for any group. RT with loads of 55‐70% 1RM characterized by a low velocity loss (VL10%) provides a very effective and efficient training stimulus since it yields similar strength gains and greater improvements in sports‐related neuromuscular performance (jump and sprint) compared to training with higher velocity losses (VL30%, VL45%). These findings indicate that the magnitude of VL reached in each exercise set considerably influences the observed training adaptations.
... This novel procedure demonstrated that it is possible to estimate the 1RM without applying direct or indirect methods (González-Badillo and Sánchez-Medina, 2010). From that period to now, several studies proposed regression equations based on the load-velocity relationship in different resistance exercises, such as the full, parallel, and half squat Sánchez-Medina et al., 2017), 45 • inclined leg-press (Conceição et al., 2016), prone-bench pull (Sánchez-Medina et al., 2014) pull-up (Sánchez-Moreno et al., 2017, deadlift (Benavides-Ubric et al., 2020), and shoulder press (Hernández-Belmonte et al., 2020). However, all predictive equations are specific for trained young adults, which means that they might not be accurate to estimate the 1RM in other populations, such as older adults. ...
... Our results confirmed a very strong relationship between the movement velocity and relative load in the horizontal leg-press in older women and men, which corroborates our first hypothesis. The load-velocity relationship is well studied in several resistance exercises in trained young adults (Benavides-Ubric et al., 2020;González-Badillo and Sánchez-Medina, 2010;Pareja-Blanco et al., 2020;Sánchez-Medina et al., 2017). However, the measurement of lifting velocity to predict the relative load in older adults is a scarcely investigated topic. ...
... In line with previous findings (Marcos-Pardo et al., 2019), our data show that older adults attain lower lifting velocities for each relative load in the leg-press than trained young adults in the 45 • inclined legpress (Conceição et al., 2016) and full-back squat exercises Sánchez-Medina et al., 2017). When analyzing the differences between young and older adults in velocity values in load increments of 5%, on average, the range of velocities is narrower in older adults (peak velocity: ~0.05 m⋅s − 1 ; mean velocity: ~0.03 m⋅s − 1 ) than in strength-trained young adults (peak velocity: ~0.07 to 0.13 m⋅s − 1 ; mean velocity: ~0.06 to ~0.09 m⋅s − 1 ) (Conceição et al., 2016;Pareja-Blanco et al., 2020;Sánchez-Medina et al., 2017). ...
Article
This study analyzed the predictive ability of movement velocity to estimate the relative load (i.e., % of one-repetition maximum [1RM]) during the horizontal leg-press exercise in older women and men. Twenty-four women and fourteen men living in community-dwelling centers volunteered to participate in this study. All participants performed a progressive loading test up to 1RM in the horizontal leg-press. The fastest peak velocity (PV) and mean velocity (MV) attained with each weight were collected for analysis. Linear regression equations were modeled for women and men. We observed very strong linear relationships between both velocity variables and the relative load in the horizontal leg-press in women (PV: r² = 0.93 and standard error of the estimate (SEE) = 5.96% 1RM; MV: r² = 0.94 and SEE = 5.59% 1RM) and men (PV: r² = 0.93 and SEE = 5.96% 1RM; MV: r² = 0.94 and SEE = 5.97% 1RM). The actual 1RM and the estimated 1RM using both the PV and MV presented trivial differences and very strong relationships (r = 0.98–0.99) in both sexes. Men presented significantly higher (p < 0.001–0.05) estimated PV and MV against all relative loads compared to women (average PV = 0.81 vs. 0.69 m·s⁻¹ and average MV = 0.44 vs. 0.38 m·s⁻¹). Our data suggest that movement velocity accurately estimates the relative load during the horizontal leg-press in older women and men. Coaches and researchers can use the proposed sex-specific regression equations in the horizontal leg-press to implement velocity-monitored resistance training with older adults.
... Load-velocity relationships have been extensively studied for exercises such as the bench press [16][17][18][19][20][21][22][23], squat [17,19,[24][25][26][27], deadlift [19,28,29], bench pull [13,30], shoulder press [11,15,31], hip thrust [17,32] and pullup [33,34]. However, even though the inclined leg press is a recurring exercise for lower-limb strengthening, the load-velocity relationship for this exercise has not been extensively studied. ...
... This might be a practical tool in real situations given that coaches and athletes/trainees are generally interested in estimating load from velocity data. Therefore, the inclined leg press exercise can be added to the extensive list of basic strength training exercises in which real-time velocity is an appropriate indicator of the relative load [5,11,27]. ...
... One of the main limitations of this study is that the loads computed for further analysis were only those from trials within the 50%-100% 1RM range. This was justified by the limitation to maximally apply force under light loads [27,28]. Therefore, the reference data provided can only be applied to this load range. ...
Article
The objectives of this study were threefold: (i) to analyze the load-velocity relationships between mean propulsive velocity (MPV), mean velocity (MV), peak velocity (PV), and relative load during the inclined leg press exercise; (ii) to analyze the differences in the load-velocity relationships between males and females; and (iii) to determine gender-specific predictive equations for loads between 50%-100% one-repetition maximum (1RM) in a population of trained young college students. The load-velocity relationships of 15 males and 13 females were explored through a progressive loading test, up to the individual 1RM load. Gender-specific load-velocity relationships were plotted along with the individual relationships. High to very high associations were found for gender-specific load-MPV and load-MV relationships , whereas load-PV presented moderate associations. The gender-specific load-velocity relationships in males were steeper than in females for MPV, MV and PV. However, individual load-velocity relationships presented higher associations than gender-specific relationships for all subjects. Finally, the predicted velocity outcomes for each %1RM load were always significantly higher in males than in females, except for PV at 95% and 100% 1RM load. Taken collectively, the findings from the present study support the application of subject-specific and gender-specific load-velocity relationships, highlighting the disparities between male and female relationships.
... Among these, 12 were evaluated in the squat exercise and 22 in the bench-press exercise. Based on previous similar outcomes [19,25], apriori analysis suggested that a minimum sample size of 12 subjects was needed to observe a 0.5 m·s −1 change in movement velocity, with an α = 0.05, and statistical power = 0.80 (G*Power, v.3.1.7, University of Kiel, Kiel, Germany). ...
... In the squat exercise, the participants started from the upright position (knees and hips fully extended) and the barbell resting across the back at the level of the acromion. Then, they start to descend until the top of the thighs was below 90 • (eccentric phase) and the concentric phase was made at the maximum velocity to the initial position [24,25]. Trained spotters (i.e., two strength coaches) were present on both sides of the barbell to ensure safety. ...
... The initial load was set at 20 and 30 kg for all participants in the bench press and squat exercises, respectively, and was gradually increased by 10 kg increments. The test ended for each participant when they attained concentric MPV of 0.4 m·s −1 in the bench press and 0.6 m·s −1 in the squat, correspondent to 85% 1RM in both [22,25]. Inter-set recoveries ranged from 3 minutes (light) to 5 minutes (heavy loads). ...
Article
Background and objective: The purpose of this study was to investigate the effect of specific warm-up on squat and bench press resistance training. Methods: Thirty-four resistance-trained males (23.53 ± 2.35 years) participated in the current study. Among these, 12 were evaluated in the squat and 22 in the bench press. After determining the maximal strength load (1RM), each participant performed a training set (3 × 6 repetitions) with 80% 1RM (training load) after completing a specific warm-up and without warming up, in random order. The warm-up comprised 2 × 6 repetitions with 40% and 80% of the training load, respectively. Mean propulsive velocity, velocity loss, peak velocity, mechanical power, work, heart rate and ratings of perceived exertion were assessed. Results: The results showed that after the warm-up, the participants were able to perform the squat and bench press at a higher mean propulsive velocity in the first set (squat: 0.68 ± 0.05 vs. 0.64 ± 0.06 m⋅s-1, p = 0.009, ES = 0.91; bench press: 0.52 ± 0.06 vs. 0.47 ± 0.08 m⋅s-1, p = 0.02, ES = 0.56). The warm-up positively influenced the peak velocity (1.32 ± 0.12 vs. 1.20 ± 0.11 m⋅s-1, p = 0.001, ES = 1.23) and the time to reach peak velocity (593.75 ± 117.01 vs. 653.58 ± 156.53 ms, p = 0.009, ES = 0.91) during the squat set. Conclusion: The specific warm-up seems to enhance neuromuscular actions that enable a higher movement velocity during the first training repetitions and to allow greater peak velocities in less time.
... Data were exported to an excel spreadsheet, and linear regressions were used to determine the 1-RM from the L-V relationship (Jovanović & Flanagan, 2014). Velocities of 0.17 m/s and 0.33 m/s for BP (Janicijevic et al., 2021) and BS exercises (Sánchez-Medina et al., 2017) were used, respectively, to estimate 1-RM for pre-and post-test. This method presents a standard error of the estimate of ∼ 4.6% and ∼ 4.3% for BP and BS, respectively (Janicijevic et al., 2021;Sánchez-Medina et al., 2017). ...
... Velocities of 0.17 m/s and 0.33 m/s for BP (Janicijevic et al., 2021) and BS exercises (Sánchez-Medina et al., 2017) were used, respectively, to estimate 1-RM for pre-and post-test. This method presents a standard error of the estimate of ∼ 4.6% and ∼ 4.3% for BP and BS, respectively (Janicijevic et al., 2021;Sánchez-Medina et al., 2017). ...
Article
This study aimed to determine the effect of the intra-session exercise sequence of a concurrent training programme on the components of health-related physical fitness. Twenty-four healthy young adults were allocated into two different groups differing only in the exercise order to conduct an 8-week intra-session concurrent training programme consisting of three sessions of 60–90 minutes (180–270 min/week), with all-out running sprint intervals, back squat, and bench press endurance and resistance exercises (i.e., ET+RT and RT+ET). The 8-week intra-session concurrent training programme overall improved all the components of physical fitness regardless of the exercise sequence. However, ET + RT and RT + ET groups reported moderate and small improvements for squat jump (ET + RT: 3.82 cm [1.11 to 6.53 cm]; RT + ET: 0.31 cm [−1.72 to 2.33 cm]), countermovement jump (ET + RT: 3.76 cm [1.43 to 6.08 cm]; RT + ET: 2.07 cm [−0.03 to 4.17 cm]) and maximum oxygen uptake (ET + RT: 4.75 ml/kg/min [1.14 to 8.35 ml/kg/min]; RT + ET: 1.66 ml/kg/min [−0.89 to 4.21 ml/kg/min]), respectively. Therefore, greater lower-body power and cardiorespiratory fitness gains might be induced following the ET + RT sequence.
... A série foi interrompida quando a velocidade da barra diminuiu em duas repetições consecutivas. Se o mesmo deslocamento da barra não fosse replicado ou a velocidade controlada da barra durante a fase excêntrica não fosse alcançada, uma nova série era feita após 3 minutos de descanso [25]. A repetição mais rápida do BS em cada carga foi considerada para a análise. ...
... A fase de propulsão é a porção da fase concêntrica que ocorre até a fase de frenagem. Quando a aceleração (a) medida é maior do que a aceleração devido à gravidade, ou seja, a ≥ -9,81 m.s-2 [13,25]. ...
Article
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Objetivos: Os objetivos deste estudo foram: 1) comparar a relação carga-velocidade estimada pelo método de dois pontos entre homens e mulheres destreinados durante o exercício agachamento paralelo (BS) e 2) comparar o perfil carga-velocidade encontrado em nosso estudo com os perfis de carga-velocidade relatados na literatura científica para indivíduos treinados. Além disso, comparar a velocidade de 1RM medida com a velocidade de 1RM predita pelo método de dois pontos no exercício BS em indivíduos destreinados. Métodos: Setenta e seis indivíduos destreinados (38 homens (22,7 ± 4,4 anos; 174,9 ± 6,8 cm; 76,1 ± 14,9 kg) e 38 mulheres (24,7 ± 4,3 anos; 159,1 ± 6,0 cm; 64,7 ± 13,3 kg) realizaram um teste de uma repetição máxima e um teste progressivo de duas cargas com 20% e 70% 1RM para estimar suas relações carga-velocidade. Resultados: Os principais resultados revelaram que 1) a velocidade média propulsiva e a velocidade média atingida em cada carga relativa foram diferentes entre homens e mulheres (p < 0,05). No entanto, a velocidade de 1RM medida não foi significativamente diferente entre eles. Homens destreinados forneceram uma relação carga-velocidade mais acentuada do que as mulheres. Descobrimos que 2) os indivíduos destreinados de nosso estudo apresentaram um perfil carga-velocidade diferente dos indivíduos treinados dos estudos da literatura científica. Além disso, 3) a velocidade de 1RM medida foi menor do que a velocidade de 1RM predita (p < 0,05). Conclusão: Esses resultados sugerem que a relação carga-velocidade é dependente do sexo e treinamento, e que o método de dois pontos usando 20% e 70% 1RM não seria confiável para estimar a relação carga-velocidade no exercício agachamento paralelo em homens e mulheres destreinados. Palavras-chave: exercício; mensuração da velocidade; força muscular.
... 20% velocity loss threshold) [25]. Because movement velocity and barbell load are is inversely related [26,27], changes in velocity attained against a given load are indicative of changes in an individual's performance capabilities. Indeed, a decline in barbell velocity is representative of neuromuscular fatigue [28], whereas greater velocity attained against a given absolute load indicates enhanced muscle strength [26]. ...
... Because movement velocity and barbell load are is inversely related [26,27], changes in velocity attained against a given load are indicative of changes in an individual's performance capabilities. Indeed, a decline in barbell velocity is representative of neuromuscular fatigue [28], whereas greater velocity attained against a given absolute load indicates enhanced muscle strength [26]. Thus, VBT can be used to objectively manipulate resistance training load according to an individual's current physiological state. ...
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Background: Velocity-based training (VBT) may be an effective method for monitoring resistance training load because it accounts for daily changes in an individual’s physical performance capabilities. However, the current evidence comparing VBT to alternative resistance training methods is dominated by small individual studies reporting mixed results. A systematic review is required to increase precision, explore heterogeneity, and inform directions for future research. Objectives: To evaluate the effectiveness of regulating resistance training based on objective velocity feedback, compared to alternative resistance training methods that do not use velocity feedback (such as percentage of one repetition maximum, rating of perceived exertion, or repetitions in reserve), on changes in muscle strength, power, and sprint speed. Data sources: Systematic searches of PubMed, Embase, SportDiscus, CINAHL, Cochrane Central, ClinicalTrials.gov, ISRCTN, and SportRxiv, and citation searching until June 2021. Study eligibility criteria: Eligible studies included randomised trials that assessed muscle strength, power, or sprint speed in healthy participants before and after a VBT intervention and an alternative resistance training intervention lasting at least four weeks. Appraisal and synthesis: Standardised mean differences (SMDs) were pooled using a random effects model with a multi-level structure. Risk of bias was assessed with the Risk of Bias 2 (RoB 2) tool and the quality of evidence was evaluated using the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. Results: Four trials met the eligibility criteria, comprising 27 effect estimates and 88 participants. The main analyses showed trivial differences and imprecise interval estimates for effects on muscle strength (SMD 0.06, 95% CI -0.51 to 0.64; I2 = 42.9%; 10 effects from 4 studies; low quality evidence), power (SMD 0.11, 95% CI -0.28 to 0.49; I2 = 13.5%; 10 effects from 3 studies; low quality evidence), and sprint speed (SMD -0.10, 95% -0.72 to 0.53; I2 = 30.0%; 7 effects from 2 studies; very low quality evidence). The results were robust to various sensitivity analyses. Conclusion: The current evidence does not support the use of objective velocity feedback over alternative methods of regulating resistance training load to elicit improvements in muscle strength, power, or sprint speed. Further well-designed trials with larger samples are required to increase the precision of the effect estimates and overall quality of evidence. Registration: The review was preregistered on the Open Science Framework (https://osf.io/pz9fs).
... In addition, some researchers maintain that this relationship is very stable regardless of the modifications of the 1RM and the training experience of the participants (González-Badillo et al., 2017a, 2017b. It is known that the fastest repetition velocity attained during a set in the presence of an absolute load can be used as a good estimator of the relative intensity that this resistance represents at each moment with each exercise Sánchez-Medina, Pallarés, Pérez, Morán-Navarro, & González-Badillo, 2017). More recently, it has been proven that the mean velocity loss during the set is a reliable and quantifiable indicator that reflects the induced neuromuscular fatigue degree (Pareja-Blanco et al., 2016;, and therefore can be used as a variable to monitor resistance training and adjust the set load (González-Badillo et al., 2017b). ...
... These devices require the trajectory of the bar movement to be linear so that the recording is as reliable and accurate as possible (Harris et al., 2010;. Specifically, the linear velocity transducer used for this study as a 'gold-standard' (T-Force System) has been widely used to evaluate kinetic and kinematic variables in resistance exercises González-Badillo et al., 2011, 2014González-Badillo et al., 2017a;Pareja-Blanco et al., 2016;Sánchez-Medina et al., 2017). The high reliability (ICC = 1.00, ...
Article
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The purpose of this study was to analyse the reliability and validity of an opto-electronic sensor system (Velowin) for assessment of the bar-velocity in the deep squat exercise. Mean velocity , mean propulsive velocity and peak velocity generated in the deep squat exercise performed in the Smith machine bar were analysed compared to a linear velocity transducer considered as the gold standard. The study was conducted with a sample of 26 men with experience in resistance training. Six measurements were analysed for squat exercise in concentric phase using a progressive loading increase. Three consecutive repetitions were performed per load with a 3-4 min recovery between loads. Analysis of variance confirmed that there were no significant differences (p > 0.05) for the velocity variables between Velowin and T-Force for each of the loads. The reliability analysis showed high values of the intraclass correlation coefficient (ICC = 0.94-0.99), an 'almost perfect' Lin's concordance coefficient (CCC = 0.99) and a low coefficient of variation (CV <3.4%) for each of the loads and velocities. These results confirm the reliability and validity of the Velowin device for measuring the execution velocity in deep squat exercise. ARTICLE HISTORY
... Our results showed a strong association of the relative load with MV and PV (Figure 2), using both the linear and polynomial fit. These results concur with previous research (Benavides-Ubric, et al., 2020;Conceicao, et al., 2015;Garcia-Ramos, et al., 2019;Gonzalez-Badillo & Sanchez-Medina, 2010;Sánchez-Medina, et al., 2017;Sanchez-Moreno, et al., 2017) and extend current evidence to female breast cancer survivors, indicating that it is possible to accurately determine the %1RM that a given load represents during the concentric phase of the bilateral leg-press exercise, provided the movement is performed at maximal intended velocity. ...
... Therefore, we cannot ascertain that the present results will be generalizable to female breast cancer survivors with very low strength levels. However, previous studies (Gonzalez-Badillo & Sanchez-Medina, 2010;Sánchez-Medina, et al., 2017;Sanchez-Moreno, et al., 2017) have shown a high stability of the velocity attained at different exercises with each percentage of 1RM in participants with very diverse strength levels, especially in women (Torrejón, Balsalobre-Fernández, Haff, & García-Ramos, 2019). Therefore, it is very likely that the regression equations presented here would be applicable to most female breast cancer survivors. ...
Article
The aims of this study were: i) to analyze the load-velocity relationship in the bilateral leg-press exercise in female breast cancer survivors, ii) to assess whether mean velocity (MV) or peak velocity (PV) show stronger relationship with the relative load, and iii) to examine whether linear (LA) or polynomic (PA) adjustment predict the velocities associated with each %1RM with greater precision. Twenty-two female breast cancer survivors (age: 50.2±10.8 years, weight: 69.6±15.2 kg, height: 160.51±5.25 cm) completed an incremental load test until 1RM in the bilateral leg-press exercise. The MV and the PV of the concentric phase were measured in each repetition using a linear velocity transducer, and were analyzed by regression models using LA and PA. A very close relationship of MV (R²=0.924; p<0.0001; SEE=0.08m.s⁻¹ by LA, and R²=0.952; p<0.0001; SEE=0.063 m.s⁻¹ by PA) and PV (R²=0.928; p<0.0001; SEE=0.119 m.s⁻¹ by LA and R²=0.941; p<0.0001; SEE=0.108 m.s⁻¹ by PA) with %1RM were observed. The MV of 1RM was 0.24±0.03 m·s⁻¹, whereas the PV at 1RM was 0.60±0.10 m.s⁻¹. A comprehensive analysis of the bilateral leg-press load-velocity relationship in breast cancer survivors is presented. The results suggest that MV is the most recommendable velocity variable to prescribe the relative load during resistance training, and that the PA presents better accuracy to predict velocities associated with each %1RM, although LA is sufficiently valid to use this model as an alternative to the quadratic model. The implications for resistance training in breast cancer are discussed.
... The MCV of a lift is defined as the average speed attained during the concentric phase of a movement (9,11). Furthermore, studies have shown a near-perfect inverse relationship between velocity and loads where velocity tends to decrease as loads increase in intensity (20,21). Technology that can easily be utilized in strength and conditioning facilities, such as linear position transducers, provide health and fitness professionals a field-based tool for assessing MCV (5,16). ...
... Employing fewer warm-up sets than previously recommended would be useful for strength and conditioning professionals working with athletes who have limited time availability for 1RM testing. However, issues with previous research evaluating the estimation of 1RM values with fewer warm-up sets are 1) exclusion of female participants, 2) evaluation of exercises not traditionally used for 1RM protocols (i.e., latpulldown and seated row), and 3) exclusion of free weight bench press, which is commonly used for assessing muscular strength (13, 18,19,21). Therefore, the purpose of this study was to determine whether the number of warm-up sets and relative intensity impacts the prediction of velocity-based 1RM values. ...
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International Journal of Exercise Science 14(4): 971-979, 2021. The purpose of this study was to determine whether the number of warm-up sets and relative intensity impacts the prediction of velocity-based one-repetition maximum (1RM) values. Twenty resistance-trained individuals (males: n = 10, females: n = 10) participated in this study. Warm-up sets consisted of subject's bench-pressing loads at 50 (five-repetitions), 70 (three-repetitions), and 90% (one-repetition) of estimated 1RM. A maximum of four attempts were performed to determine 1RM, while recording mean concentric velocity (MCV) using a linear position transducer during warm-up and 1RM trials in order to develop load-velocity profiles. Specifically, four different velocity-based 1RM equations (EQ) were developed from the warm-up sets of 50, 70, and 90% (MCV-EQ1), 50 and 90% (MCV-EQ2), 70 and 90% (MCV-EQ3), and 50 and 70% (MCV-EQ4). Constant error (CE) for the MCV prediction equations were not statistically significant for any comparisons (CEs = 0.80 to 2.96kg, all p > 0.05). Correlation coefficients between the MCV prediction methods and measured 1RM were near perfect for all comparisons (r ≥ 0.98, all p < 0.001). The standard error of estimate (SEE) and 95% limits of agreement (LOAs) were lowest for MCV-EQ1 (7.86 kg and ± 15.00 kg, respectively) and slightly higher for MCV-EQ3 (9.24 kg and 17.74 kg, respectively). Nonetheless, SEEs and 95% LOAs for MCV-EQ2 (8.10 kg and ± 15.55kg, respectively) and MCV-EQ4 (8.38 kg and ± 16.08 kg, respectively) were similar as MCV-EQ1. Current study results indicated that an additional warm-up set only slightly increases the accuracy of velocity-based 1RM estimations. Furthermore, larger differences in relative intensity will help produce slightly more accurate 1RM values.
... Many previous studies have shown a relationship between load and velocity which can be presented as the force-velocity profile [3,5,22,[24][25][26]. The load-velocity or forcevelocity profile demonstrates that with increasing load, the velocity should decrease and vice-versa. ...
... Characteristics of studies included in review.Table 1. Cont. BS 1RM: PVBT: ↑ 19.6%, OTL: ↑ 18.3% BP 1RM: PVBT: ↑ 8.5%, OTL: ↑ 10.2% DL 1RM: PVBT: ↑ 10.9, OTL: ↑ 22.9% BS PP: PVBT: ↑ 18.3%, OTL: ↑ 20.1% BP PP: PVBT: ↑ 14.5%, OTL: ↑ 27.9%, DL PP: PVBT:↑ 15.7%, OTL: ↑ 20.1% Note: P3, third training phase; VO 2max , maximal oxygen uptake; VT2, ventilatory threshold; PS max paddling speed at VO 2max , paddling speed at VT2; 1RM, one repetition maximum; BP, bench press; PBP, prone bench pull; T0, first date of tests during training cycle; T3, last date of tests during training cycle; U16, under-16 team; U18, under-18 team; U21, under-21 team; RT, resistance training; V1LOAD, the load that elicited 1.00 m/s velocity in the full squat exercise; CMJ, countermovement jump; MAS, maximal aerobic speed; FS, full squat; CMJ 20 , countermovement jump with 20 kg; FS 20-30-40 , full squat with load: 20, 30, 40 kg; FS 50-60 , full squat with load: 50, 60 kg; T[20][21][22][23][24][25][26][27][28][29][30] acceleration capacity between 20 and 30 m; VL15, group that trained with a mean velocity loss of 15% in each set; VL30, group that trained with a mean velocity loss of 30% in each set; AMPV, average mean propulsive velocity attained against absolute loads common to Pre-and Post-tests in the squat progressive loading test; T30, 30-m sprint; YYIRT, Yo-yo intermittent recovery test level 1; VBT, velocity-based training; PVBT, progressive velocity-based training; OTL, optimum training load; BS, back squat; DL, deadlift; PP, peak power output; FSG, full squat group; COM, combined group; CG, control group. ...
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Due to drawbacks of the percentage-based approach, velocity-based training was proposed as a method to better and more accurately prescribe training loads to increase general and specific performance. The purpose of this study was to perform a systematic review of the studies that show effects of velocity-based resistance training on strength and power performance in elite athletes. Electronic searches of computerized databases were performed according to a protocol that was agreed by all co-authors. Four databases—SportDiscus with Full Text and MEDLINE via EBSCO, SCOPUS, and Web of Science—were searched. Seven studies were found which researched the effects of velocity-based resistance training on athletes after a given training period. The analyzed studies suggest that applying velocity losses of 10–20% can help induce neuromuscular adaptations and reduce neuromuscular fatigue. Using velocity zones as part of a separate or combined (e.g., plyometric) training program can elicit adaptations in body composition and performance parameters. Moreover, velocity zones can be programmed using a periodized or non-periodized fixed velocity zones protocol. Lastly, obtaining instantaneous feedback during training is a more effective tool for increasing performance in sport-specific parameters, and should be used by sport practitioners to help keep athletes accountable for their performance.
... Since this study was conducted on a VBRT approach, individualization of the relative load (%1RM) for each testing session was determined from the general load-velocity relationship for SQ [23] and BP [24]. Thereby, the target velocity to be attained in the first (usually the fastest) repetition of the first set of each session was used as an indicator of the relative load for all subjects. ...
... A detailed description of the progressive loading test protocol for both exercises has been provided elsewhere [23,28], and the execution technique was exactly reproduced throughout the study. For the full SQ exercise, subjects started from the upright position with the knees and hips fully extended, stance approximately shoulder-width apart, and the barbell resting across the back at the level of the acromion. ...
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This study aimed to compare the effect on bar execution velocity and number of repetitions between two velocity-based resistance training protocols only differing in the set configuration of the full-squat (SQ) and bench-press (BP) exercises. Moderately strength-trained men were assigned to a traditional (TS, n = 9)- or an alternating-set (AS, n = 10) configuration group to perform four testing sessions against different relative loads (55–60–65–70% 1RM). Relative load, magnitude of intra-set velocity loss (%VL), number of sets, inter-set recovery time, and exercise order were matched for both groups in each session. Mean propulsive velocity of the first repetition (MPVfirst), average number of repetitions per set (NRS), total number of repetitions (TNR), and total training time per session (TT) were measured. No significant differences between training conditions were observed for any relative load in MPVfirst, NRS, and TNR in both exercises. The TS group completed a significantly higher number of repetitions (p < 0.05) at faster velocities (MPV > 0.9–1.1 m·s−1) in the SQ. In conclusion, training sessions performing AS between SQ and BP exercises with moderate relative loads and %VL result in similar bar execution velocity and volume, but in a more time-efficient manner, than the traditional approach
... Este estudio no identifico diferencias significativas entre los grupos para ninguno de los tres parámetros examinados (Potencia máxima, potencia media propulsiva y potencia pico), aunque identifico cierta tendencia hacia cargas de Pmax ligeramente más bajas para el grupo más fuerte (G3). En un estudio posterior Sánchez-Medina et al. (Sánchez-Medina, Pallarés, Pérez, Morán-Navarro, & González-Badillo, 2017) también con hombres deportistas verificaron si la velocidad alcanzada en cada% 1RM en sentadilla profunda dependía de los niveles de la TFR, los sujetos fueron clasificadas en tres subgrupos según su TFR grupo 1 (G1), n = 24, TFR ≤ 1.30; grupo 2 (G2), n = 29, 1.30 < TFR ≤ 1.50; y grupo 3 (G3), n = 27, TFR > 1.50., no encontraron diferencias significativas para la VMP alcanzada en cada % de 1RM, o en la media de la velocidad de 1RM entre grupos, tampoco se presentó correlación entre V1RM y TFR. González-Badillo et al. (Gonzalez-Badillo & Sanchez-Medina, 2010) (Conceicao, Fernandes, Lewis, Gonzalez-Badillo, & Jimenez-Reyes, 2016) indican que el perfil de carga-velocidad no parece diferir entre los participantes emparejados por edad y con diferentes TFR. ...
... Estas diferencias entre los estudios podrían deberse a que los participantes de los estudios de Sánchez-Medina et al.(2017) eran atletas, hombres con una TFR en sentadilla profunda superiores a 1,0, mientras que en el presente estudio las participantes eran mujeres, no deportistas y con una TFR de 0.65 para el grupo débil y 0.84 para el grupo fuerte. Uno de los principales inconvenientes de estos estudios como lo plantea Torrejón et al. (2019) es que, el perfil de la velocidad de carga ha sido analizado casi que exclusivamente en hombres. ...
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Objetivo: Comparar la tasa de fuerza relativa (TFR) con distintos indicadores de fuerza en mujeres jóvenes. Métodos: Se evaluaron a 146 mujeres que se distribuyeron en tres grupos de acuerdo con los resultados de la TFR obtenida en el ejercicio de sentadilla y se compararon los resultados obtenidos en las pruebas de Fuerza prensil de la mano derecha e izquierda (FPMD- FPMI), Fuerza isométrica miembros inferiores (FIMI), Fuerza máxima de pecho (FMP), Fuerza máxima en sentadilla (FMS) Velocidad de desplazamiento sobre treinta metros (V30), altura del salto en (CMJ), potencia de pedaleo (PP) y la velocidad media propulsiva de miembros superiores e inferiores (VMPMS-VMPMI) obtenida al 50%, 60%, 70% y 80% de una repetición máxima en sentadilla. Resultados: Se observaron diferencias significativas (p?0,01) entre los grupos en la FMS, CMJ, V30, VMP y PP, y la mayoría de las variables presentaban la diferencia entre el G1 y G3 (p?0,01).
... The 1RM SQ and 1RM BP were estimated using a linear position transducer (Chronojump, Boscosystem, Barcelona, Spain) for measuring movement velocity. The assessment began after a specific warm up protocol previously used [25]. Both exercises were assessed using a squat rack, a bench, and an Olympic barbell (Taurus, Argentina). ...
... Three repetitions were performed with each load with a 3-min rest interval between each set. The test was concluded when participants reached a mean propulsive velocity (MPV) close to 0.5 m/s and the 1RM value was estimated from the velocity attained with the heaviest load used, as previously described [25]. Bench press was performed starting from a complete extension of the elbows until the barbell touched the chest. ...
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BACKGROUND: This study examined the differences in physical and anthropometric traits between specific playing positions (i.e., forwards: front row, second row, back row; backs: half backs, centers, wings/fullbacks) in amateur rugby players and analyzed the magnitude of correlations among jump, sprint, and strength measures in forwards and backs. METHOD: Sixty-four male rugby players were assessed in anthropometrics, a variety of vertical jumps, 10- and 30-m sprint, and strength tests (i.e., squat and bench press). RESULTS: Front row forwards (FFR) demonstrated significantly higher body mass (BM) than second row (FSR) and back row (FBR) (107.4 ± 12.8, 99.1 ± 9.9 and 91.6 ± 7.6 kg respectively; p< 0.001). FFR showed greater absolute strength in bench press and squat, although no differences were found in relative strength. Regarding the differences in jump performance, FBR and FSR showed significantly (p< 0.05) and significant to non-significant (p= 0.042–0.078, ES = 0.90–1.55) higher jumps in all tasks compared to FFR. Moreover, FBR demonstrated lower sprint times and greater maximum sprinting speed (MSS) than FFR (p< 0.01). For the backs, centers (BCEN) were significantly heavier (p< 0.05) and exhibited a non-significantly moderate larger sprint momentum (p= 0.068, ES = 0.75) compared to half backs (BHB). MSS values were small to moderately greater in favor of wings/fullbacks [BWFB] (p= 0.188–0.059, ES = 0.50–0.71). Finally, statistically significant correlations were found between drop jump (flight time) and jump height across all jump tasks, sprint times and speed for both forwards (r= 0.541 to 0.996, p< 0.001) and backs (r= 0.422 to 0.995, p< 0.05). CONCLUSIONS: In conclusion, FFR demonstrated significant, small to very large differences, when compared to their specific peers, whereas the backs were more similar. Additionally, our results indicated moderate to strong associations between explosive tasks such as sprinting and jumping in both playing positions.
... MPV + 117.0 (standard error of estimate = 4.0% 1RM). 20 In addition to 1RM, 3 other variables derived from this test were used to analyze how the different training interventions affected the load-velocity relationship: (1) average MPV attained against all absolute loads common to pretraining and posttraining (AV), (2) average MPV attained against absolute loads that were moved faster than 1 m·s −1 at pretraining (AV>1, "light" loads), and (3) average MPV attained (Ahead of Print) against absolute loads that were moved slower than 1 m·s −1 at pretraining (AV<1, "heavy" loads). A linear velocity transducer (T-Force System; Ergotech, Murcia, Spain), whose reliability has been reported elsewhere, 12 was used to measure bar velocity. ...
... Relative intensities were determined from the load-velocity relationship for the SQ exercise. 20 Thus, a target MPV to be attained in the first (usually the fastest) repetition of the first exercise set in each session was used as an estimation of %1RM. The absolute load (in kilogram) was individually adjusted to match the velocity associated (±0.03 m·s −1 ) with the %1RM intended for each session. ...
Article
Purpose: This study analyzed the effects of 3 training interventions: 1 isolated endurance training (ET) and 2 concurrent training (CT), which differed in the velocity loss (VL) magnitude allowed during the resistance training (RT) set: 15% (VL15) versus 45%, on strength and endurance running performance. Methods: A total of 33 resistance- and endurance-trained men were randomly allocated into 3 groups: VL15, VL 45%, and ET. ET was similar across all groups. The CT groups differed in the VL allowed during the RT set. Before and after the 8-week training program the following tests were performed: (1) running sprints, (2) vertical jump, (3) progressive loading test in the squat exercise, and (4) incremental treadmill running test up to maximal oxygen uptake. Results: Significant differences (P < .001) in RT volume (approximately 401 vs 177 total repetitions for VL 45% and VL15, respectively) were observed. Significant "group" × "time" interactions were observed for vertical jump and all strength-related variables: the CT groups attained significantly greater gains than ET. Moreover, a significant "group" × "time" interaction (P = .03) was noted for velocity at maximal oxygen uptake. Although all groups showed increases in velocity at maximal oxygen uptake, the VL15 group achieved greater gains than the ET group. Conclusions: CT interventions experienced greater strength gains than the ET group. Although all groups improved their endurance performance, the VL15 intervention resulted in greater gains than the ET approach. Therefore, moderate VL thresholds in RT performed during CT could be a good strategy for concurrently maximizing strength and endurance development.
... In fact, since strong correlation has been shown between execution velocity and 1RM (García-Ramos, Pestaña-Melero et al., 2018;Muñoz-López et al., 2017;Pérez-Castilla et al., 2020), the VBT monitoring allows the creation of individualised velocity profile (Alcazar et al., 2017;Banyard et al., 2018), as well as the degree of fatigue (García-Ramos, Torrejón et al., 2018;Haff & Nimphius, 2012;Sánchez-Medina & González-Badillo, 2011). Hence, VBT facilitates the prescription of personalised velocity training zones and the knowledge of the athlete's physiological state (Conceição et al., 2016;González-Badillo et al., 2015;González-Badillo & Sánchez-Medina, 2010) in a robust, non-invasive, and highly sensitive way (González-Badillo & Sánchez-Medina, 2010;Martínez-Cava et al., 2019;Morán-Navarro et al., 2019;Sánchez-Medina & González-Badillo, 2011;Sánchez-Medina et al., 2017). ...
... In the field of VBT, TEM and SEM values of the maximum concentric velocity of 0.07-0.10 m/s can affect the 1RM values by 5% (González-Badillo & Sánchez-Medina, 2010;Martínez-Cava et al., 2019;Sánchez-Medina & González-Badillo, 2011;Sánchez-Medina et al., 2017). All of these values can help standardise the analysis of the results. ...
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This systematic review aimed to summarise and analyse the evidence on the reliability and validity of linear tranducers (LTs) in exercises of different nature and different modes of execution. This systematic review was carried out under PRISMA guidelines, and was carried out using three databases (PubMed, Web of Sciences, and Scopus). Of the 351 initially found, 21 were included in the qualitative synthesis. The results reflected that linear position transducers (LPTs) were valid and reliable in monitoring movement velocity in non-plyometric exercises. However, precision and reliability were lower in execution protocols without isometric phase and in the execution of exercises in multiple planes of movement, with greater measurement errors at higher sampling frequencies. On the other hand, linear velocity transducers (LVTs) proved to be valid and reliable in measuring velocity during plyometric and non-plyometric exercises performed on the Smith machine, with less variation in measurement in the latter. Finally, the use of peak values is recommended, since they are less dependent on the technological errors of LTs. Therefore, the performance of non-plyometric exercises, carried out in the Smith machine and with an isometric phase in the execution of the movement, will help to minimise the technological error of the LTs.
... The MPV was calculated as the moment where the total acceleration (summation of inertial acceleration 1 the acceleration of gravity) was higher than 29.81 m·s 22 and analyzed from each repetition using the manufacturer's software (SmartCoach, v.5.8.0.4 for Windows). The estimated RM for each subject was calculated using individual linear regression, setting load (in kg) as the independent variable, the best MPV repetition from each set as the dependent variable, and a general theoretical RM speed specific for the full squat of 0.32 m·s 21 (34). ...
Article
Muñoz-López, A, Marín-Galindo, A, Corral-Pérez, J, Costilla, M, Sánchez-Sixto, A, Sañudo, B, Casals, C, and Ponce-González, JG. Effects of different velocity loss thresholds on passive contractile properties and muscle oxygenation in the squat exercise using free weights. J Strength Cond Res XX(X): 000-000, 2021-The current study assessed the impact between different velocity loss thresholds on changes in the muscle contractile properties and muscle oxygenation after a single resistance training (RT) session. Thirty physically active men participated in a crossover study performing 3 sets of the squat exercise at a lifted speed of ≈0.75 m·s -1, with 2 different velocity loss thresholds: 20% (VL20) vs 40% (VL40) in a randomized order. Contractile properties of the knee extensor muscles were tested using tensiomyography. In addition, muscle oxygenation was continuously measured from baseline until the end of the exercise session. The vastus lateralis showed a significant moment by condition interaction in time delay (p = 0.044), muscle displacement (p = 0.001), and contraction velocity (p = 0.007), with greater reductions in VL40. In both trainings, oxygenated hemoglobin and tissue oxygen index decreased, whereas deoxygenated hemoglobin increased (moment as the main effect, p < 0.05), but without a moment by condition interaction. VL40 showed a lower deoxygenation slope in set 1 (-0.468%·s-1, p = 0.001) and set 3 (-0.474%·s-1, p = 0.037) as well as higher losses in set 1 (-41.50%, p = 0.003), set 2 (-41.84%, p = 0.002), and set 3 (-62.51%, p < 0.001), compared with VL20. No differences were found in the recovery period between conditions. In conclusion, during the RT program design, coaches and athletes should consider that VL40 produces higher mechanical and neuromuscular impairments than VL20, which seems to be necessary for hypertrophy to occur; however, VL40 also produces a longer period of lower oxygen supply than VL20, which can induce fast-to-slow muscle fiber transition.
... Associations between maximal and explosive strength capacities are best displayed by individual load-velocity profiles [13]. A plethora of studies analyzed load-velocity profiles using a linear velocity transducer in various settings, concluding that velocitybased monitoring of strength performance is a precise method to assess the effort and the estimated relative load of athletes [14][15][16][17]. In addition, the force-power relationship has recently received more attention in helping to maximize power performances in ballistic and multi-joint exercises [18][19][20]. ...
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This study assessed the effects of a 7-day creatine (CRE) supplementation on the load–velocity profile and repeated sub-maximal bouts in the deep squat using mean propulsive velocity (MPV) and mean propulsive power (MPP). Eleven strength-trained men (31.4 ± 5.4 years) supplemented 0.3 g·kg−1·d−1 CRE or a placebo (PLA, maltodextrin) for seven days in a randomized order, sepa-rated by a 30-day washout period. Prior to and after the supplementation, the subjects performed an incremental maximal strength (1RM) test, as well as 3 × 10 repetitions and a repeti-tions-to-failure test (RFT), all at 70% 1RM. Maximal strength remained statistically unaltered in CRE (p = 0.107) and PLA (p = 0.568). No statistical main effect for time (p = 0.780) or interaction (p = 0.737) was observed for the load–velocity profile. The number of repetitions during RFT remained statistically unaltered in both conditions (CRE: +16.8 ± 32.8%, p = 0.112; PLA: +8.2 ± 47.2%, p = 0.370), but the effect size was larger in creatine compared to placebo (g = 0.51 vs. g = 0.01). The total work during RFT increased following creatine supplementation (+23.1 ± 35.9%, p = 0.043, g = 0.70) but remained statistically unaltered in the placebo condition (+15.0 ± 60.8%, p = 0.801, g = 0.08; between conditions: p = 0.410, g = 0.25). We showed that CRE loading over seven days did not affect load–velocity characteristics but may have increased total work and power output during submaximal deep squat protocols, as was indicated by moderate effect sizes.
... Esses procedimentos são realizados assumindo a existência de um número médio aproximado de repetições máximas por série que podem ser realizadas com cada percentual de 1RM, de acordo com o tipo de exercício e o nível de treinamento do sujeito [9,10,12], e, portanto, considera-se que um certo número de repetições máximas representa uma intensidade relativa específica (%1RM). Embora essa abordagem elimine a necessidade de realizar um teste direto de 1RM, também não está isenta de desvantagens: Intensidade de treinamento como velocidade de execução na ação concêntrica (VMP da 1ª repetição) Atualmente, como resultado dos avanços tecnológicos que permitem medir a velocidade de execução em exercícios com pesos livres, há a possibilidade de determinar/estimar, com alto grau de precisão, a intensidade relativa (%1RM) que representa a carga absoluta usada na sessão de treinamento, a partir da primeira (ou mais rápida) repetição da série, sempre executada a máxima velocidade possível [5,[25][26][27][28], tudo através de equações de regressão específicas para cada exercício. Isso ocorre porque a velocidade média propulsiva da repetição mais rápida da série está intrinsecamente associada à magnitude relativa da carga (%1RM), e, portanto, cada %1RM tem sua própria velocidade [5]. ...
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Determinação e controle da intensidade e volume do treinamento de força na pesquisa nas ciências do exercício e sua aplicação. Resumo Nos estudos iniciais, que documentaram os efeitos positivos do treinamento com pesos e a execução de esforços musculares repetidos [1-3], o propósito da ciência de conhecer a melhor maneira de definir, controlar e dosar o treinamento de força tem sido uma das questões que concentraram o maior interesse e esforço. Trata-se de uma questão extremamente importante, pois os resultados originários dos trabalhos científicos de maior qualidade devem possibilitar a continuação da geração do corpo de conhecimento que ajuda a melhorar a metodologia do treinamento e, portanto, as participações na prática dos profissionais. Para que isso seja cumprido, os estudos científicos devem ter, entre outros atributos, um método preciso de determinação e controle das variáveis que definem o estímulo do treinamento proposto, a fim de verificar a relação entre ele e os efeitos produzidos. No entanto, se isso não acontecer, pesquisadores e profissionais do treinamento correm o risco de tomar decisões sobre a configuração dos estímulos (manipulação das variáveis da carga) com base em conclusões científicas "falsas" ou incertas, na melhor das hipóteses. Palavras-chave: Variáveis, dosagem, quantificação, carga, intensidade, volume.
... Rather, due to differences in participants' abilities, the uniform load conveniently elicited a wider range of observed velocities for this exercise (compared to the other configurations, where individualized loads were used and the range of velocities was narrow), which we consid-Sports 2021, 9, 123 5 of 15 ered preferable for addressing the research question over a more ample range of feasible movement speeds. The two velocity realms for squats were chosen because they correspond to intensities of~75-80% 1-RM, typically used for strength endurance training or training aimed at inducing hypertrophy, and~90% 1-RM, typically used for improving maximal strength [19,20], respectively. Moreover, these velocity realms filled out the slower end of the spectrum of typical training velocities not covered by the other three exercises. ...
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Velocity-based training (VBT) is a resistance training method by which training variables are manipulated based on kinematic outcomes, e.g., barbell velocity. The better precision for monitoring and manipulating training variables ascribed to VBT assumes that velocity is measured and communicated correctly. This study assessed the validity of several mobile and one stationary VBT device for measuring mean and peak concentric barbell velocity over a range of velocities and exercises, including low- and high-velocity, ballistic and non-ballistic, and plyometric and non-plyometric movements, and to quantify the isolated effect of device attachment point on measurement validity. GymAware (r = 0.90–1, standard error of the estimate, SEE = 0.01–0.08 m/s) and Quantum (r = 0.88–1, SEE = 0.01–0.18 m/s) were most valid for mean and peak velocity, with Vmaxpro (r = 0.92–0.99, SEE = 0.02–0.13 m/s) close behind. Push (r = 0.69–0.96, SEE = 0.03–0.17 m/s) and Flex (r = 0.60–0.94, SEE = 0.02–0.19 m/s) showed poorer validity (especially for higher-velocity exercises), although typical errors for mean velocity in exercises other than hang power snatch were acceptable. Effects of device placement were detectable, yet likely small enough (SEE < 0.1 m/s) to be negligible in training settings.
... None of the participants reached muscle failure in any of the sets. Three variables were recorded: a) the average of the mean propulsive velocity for the five loads (MPV5l); b) relative strength (RS), which was obtained from the quotient of one repetition maximum (1RM)/body weight; and c) estimation of 1RM, which was determined from the mean propulsive velocity (MPV) of the last test load, which was in turn calculated from the formula proposed by [33]. The mentioned variables were determined using a linear encoder (Chronojump ® , Barcelona, Spain). ...
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The aim of this study was to explore the anthropometric profile and evaluate physical fitness variables of the members of the Chile women's national football team based on their playing positions. Fifty football players participated in this study, which was carried out during the period of training for the France 2019 Women's World Cup and the Japan 2020 Olympic Games. Body composition and physical condition (muscular strength, sprint, agility, and aerobic fitness) were assessed. The goalkeepers showed greater weight (p < 0.001), height (p = 0.002), and %Fat (p = 0.010) compared to the rest of the playing positions. There were also differences between positions in relative strength (RS) (p = 0.001), running speed at 10 and 30 m (T10 and T30, respectively), agility (AGI) (p < 0.001), and yo-yo test (MYYR1) (p < 0.001). RS, T10, T30, and countermovement jump (CMJ) were significantly correlated (p ≤ 0.05) with anthropometric variables (p ≤ 0.05). MYYR1 was also significantly correlated with anthropometric variables (p ≤ 0.05). In conclusion, goalkeepers show greater weight and height, as well as worse results in MYYR1, AGI, T10, T30, and RS compared to the rest of the players. Forwards present better performance in running speed and agility. Better performance in physical condition is associated with better body composition values (greater muscle mass and lower fat mass). Greater relative strength indicates greater performance in explosive actions. Therefore, to meet the demands of high competition, it is important to establish ideal profiles in anthropometry and physical condition variables based on the playing position.
... Recently, simple methods of measuring movement velocities during resistance exercise have enabled the frequent and easy determination of the force-velocity profiles [12,16,27,29,36,37] and load-velocity relationships in order to create generalized equations for the estimation of maximum strength (1RM) and %1RM from movement velocity [7,11,14,15,21,26,28,32,33,35]. These approaches provide strength and conditioning coaches with useful information to monitor adaptations and adjust strength training programs. ...
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Study aim : This study compared movement velocity and force-velocity profile parameters measured by a free video analysis software program, with the use of a high-speed video recording, and a validated linear position transducer (LPT). Material and methods : Ten team-sports athletes performed double-leg and single-leg ballistic lower limb extensions on a leg press machine against a wide range of resistive loads. Each repetition was recorded by the LPT a high-speed camera (300 fps), and later analysed with a free video analysis software program. Results : Mean and peak movement velocity presented high reliability (ICC: 0.990 and 0.988, p < 0.001) and agreement between the two measuring systems (systematic bias: –0.06 ± 0.04 and –0.01 ± 0.03 m/s, respectively). Force-velocity profile parameters were also similar: maximum velocity at zero load (Vo: 1.79 ± 0.15 vs. 1.78 ± 0.12 m/s, p = 0.64), slope (b: –1585 ± 503 vs. –1562 ± 438 N · s/m, p = 0.43), maximum force at zero velocity (Fo: 2835 ± 937 vs. 2749 ± 694 N, p = 0.41) and maximum power (1274 ± 451 vs 1214 ± 285 W, p = 0.38). Both measuring systems could similarly detect the individual force or velocity deficit (p=0.91). Conclusion : In conclusion, a free video analysis software combined with a high-speed camera was shown to be a reliable, accurate, low bias and cost-effective method in velocity-based testing.
... The stance width and foot position were individually adjusted and carefully replicated on every lift. From this position, the participants were required to descend until making contact with the bench and then to perform the concentric phase of the movement in an explosive manner [29,30]. The height of the bench was individually selected and allowed each participant to descend with the hips below the knee line, according to the rules of the International Powerlifting Federation [31]. ...
Article
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Although velocity control in resistance training is widely studied, its utilization in eliciting post-activation performance enhancement (PAPE) responses receives little attention. Therefore, this study aimed to evaluate the effectiveness of heavy-loaded barbell squats (BS) with velocity loss control conditioning activity (CA) on PAPE in subsequent countermovement jump (CMJ) performance. Sixteen resistance-trained female volleyball players participated in this study (age: 24 ± 5 yrs.; body mass: 63.5 ± 5.2 kg; height: 170 ± 6 cm; relative BS one-repetition maximum (1RM): 1.45 ± 0.19 kg/body mass). Each participant performed two different conditions: a set of the BS at 80% 1 RM with repetitions performed until a mean velocity loss of 10% as the CA or a control condition without CA (CNTRL). To assess changes in jump height (JH) and relative mean power output (MP), the CMJ was performed 5 min before and throughout the 10 min after the CA. The two-way analysis of variance with repeated measures showed a significant main effect of condition (p = 0.008; η2 = 0.387) and time (p < 0.0001; η2 = 0.257) for JH. The post hoc test showed a significant decrease in the 10th min in comparison to the value from baseline (p < 0.006) for the CNTRL condition. For the MP, a significant interaction (p = 0.045; η2 = 0.138) was found. The post hoc test showed a significant decrease in the 10th min in comparison to the values from baseline (p < 0.006) for the CNTRL condition. No significant differences were found between all of the time points and the baseline value for the CA condition. The CA used in the current study fails to enhance subsequent countermovement jump performance in female volleyball players. However, the individual analysis showed that 9 out of the 16 participants (56%) responded positively to the applied CA, suggesting that the PAPE effect may be individually dependent and should be carefully verified before implementation in a training program.
... Apart from 3D motion capturing, which are considered "gold standard," linear position-velocity transducers generally seem to obtain valid and reliable movement velocities (21). Especially, the T-Force system has been used in various research settings (18,22,24) and has been validated in numerous studies, showing an excellent validity and reliability when compared with camera-based motion capturing and linear velocity-position transducer (4). Compared with other systems, IMUs do not depend on a cable-extension or a multi-camera system and are easily attached to the body or the barbell (2). ...
Article
We aimed at assessing the validity and test-retest reliability of the inertial measurement unit-based Vmaxpro sensor compared with a Vicon 3D motion capture system and the T-Force sensor during an incremental 1-repetition maximum (1RM) test and at submaximal loads. Nineteen subjects reported to the laboratory for the 1RM test sessions, whereas 15 subjects carried out another 3 sessions consisting of 3 repetitions with 4 different intensities (30, 50, 70, and 90% of 1RM) to determine the intra- and interday reliability. The Vmaxpro sensor showed high validity (Vicon: R2 = 0.935; T-Force: R2 = 0.968) but an overestimation of the mean velocities (MVs) of 0.06 ± 0.08 m·s−1 and 0.06 ± 0.06 m·s−1 compared with Vicon and T-Force, respectively. Regression analysis indicated a systematic bias that is increasing with higher MVs. The intraclass correlation coefficients (ICCs) for Vmaxpro were moderate to high for intraday (ICC: 0.662–0.938; p ≤ 0.05) and for interday (ICC: 0.568–0.837; p ≤ 0.05) reliability, respectively. The Vmaxpro is a valid and reliable measurement device that can be used to monitor movement velocities within a training session. However, practitioners should be cautious when assessing movement velocities on separate days because of the moderate interday reliability.
... Velocity-based training (VBT) uses instantaneous velocity feedback to objectively monitor and adjust the resistance training load (Orange, Metcalfe et al., 2019). Because movement velocity and barbell load are inversely related (Orange, Metcalfe et al., 2020;Sánchez-Medina et al., 2017), changes in velocity attained against a given load are indicative of changes in an individual's performance capability. Indeed, a decline in barbell velocity is associated with neuromuscular fatigue (Sánchez-Medina & González-Badillo, 2011), whereas greater velocity attained against a given absolute load indicates enhanced neuromuscular readiness . ...
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We estimated the effectiveness of using velocity feedback to regulate resistance training load on changes in muscle strength, power, and linear sprint speed in apparently healthy participants. Academic and grey literature databases were systematically searched to identify randomised trials that compared a velocity-based training intervention to a 'traditional' resistance training intervention that did not use velocity feedback. Standardised mean differences (SMDs) were pooled using a random effects model. Risk of bias was assessed with the Risk of Bias 2 tool and the quality of evidence was evaluated using the GRADE approach. Four trials met the eligibility criteria, comprising 27 effect estimates and 88 participants. The main analyses showed trivial differences and imprecise interval estimates for effects on muscle strength (SMD 0.06, 95% CI -0.51-0.63; I2 = 42.9%; 10 effects from 4 studies; low-quality evidence), power (SMD 0.11, 95% CI -0.28-0.49; I2 = 13.5%; 10 effects from 3 studies; low-quality evidence), and sprint speed (SMD -0.10, 95% CI -0.72-0.53; I2 = 30.0%; 7 effects from 2 studies; very low-quality evidence). The results were robust to various sensitivity analyses. In conclusion, there is currently no evidence that VBT and traditional resistance training methods lead to different alterations in muscle strength, power, or linear sprint speed.
... VBRT requires that the concentric phase of the exercise is performed with maximum velocity and the velocity of each individual repetition is measured. VBRT can be used to estimate the daily 1-RM using the concentric velocity of the first repetition of the exercise (after warm-up sets) to adjust the training load for that training session (González-Badillo and Sánchez-Medina 2010;Sánchez-Medina et al. 2017). Moreover, velocity loss during each set can be used to terminate the set and, in doing so, target specific training adaptations Pareja-Blanco et al. 2017). ...
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Purpose Men and women typically display different neuromuscular characteristics, force–velocity relationships, and differing strength deficit (upper vs. lower body). Thus, it is not clear how previous recommendations for training with velocity-loss resistance training based on data in men will apply to women. This study examined the inter-sex differences in neuromuscular adaptations using 20% and 40% velocity-loss protocols in back squat and bench press exercises. Methods The present study employed an 8-week intervention (2 × week) comparing 20% vs. 40% velocity-loss resistance training in the back squat and bench press exercises in young men and women (~ 26 years). Maximum strength (1-RM) and submaximal-load mean propulsive velocity (MPV) for low- and high-velocity lifts in squat and bench press, countermovement jump and vastus lateralis cross-sectional area were measured at pre-, mid-, and post-training. Surface EMG of quadriceps measured muscle activity during performance tests. Results All groups increased 1-RM strength in squat and bench press exercises, as well as MPV using submaximal loads and countermovement jump height ( P < 0.05). No statistically significant between-group differences were observed, but higher magnitudes following 40% velocity loss in 1-RM ( g = 0.60) and in low- ( g = 1.42) and high-velocity ( g = 0.98) lifts occurred in women. Training-induced improvements were accompanied by increases in surface EMG amplitude and vastus lateralis cross-sectional area. Conclusion Similar increases in strength and power performance were observed in men and women over 8 weeks of velocity-based resistance training. However, some results suggest that strength and power gains favor using 40% rather than 20% velocity loss in women.
... The peak force (PF) was continuously assessed during all attempts in the SQ at a sample frequency of 1,000 Hz by a linear position transducer (Chronojump) attached to the barbell. The assessment began after a specific warm-up protocol previously used (24). Both exercises were assessed using a squat rack, a bench, and an Olympic barbell (Taurus, Argentina). ...
Article
The aims of this study were twofold: to compare the strength-related performance between young forwards and backs rugby players and to examine the correlations between strength deficit (SDef), strength parameters, and sprint and jump performance. Fifty-seven male rugby players (mean 6 SD: age, 17.4 6 1.3 years) performed anthropometric and body composition assessments, vertical jumps, 30-m sprint, and squat (SQ) and bench press (BP) 1-repetition maximum tests (1RM SQ and BP). The differences in the tested variables between positions were analyzed through an independent t-test. A Pearson’s correlation coefficient was used to assess the relationships among the variables. Significant differences were observed for anthropometric and body composition measures and jump and sprint performance between positions (p,0.05; effect size [ES]: 0.60–1.34), except for 5-m velocity (p < 0.080; ES: 0.57). Backs demonstrated higher relative 1RM than forwards in both exercises (p < 0.009 and p < 0.008; ES 5 0.88 and 0.91, for SQ and BP, respectively). In addition, backs demonstrated lower SDef from 70 to 90% 1RM (p < 0.048) but small-to-moderate nonsignificant lower SDef against lighter loads compared with forwards (50–60% 1RM). Overall, SDef across all loads (r: 0.378 to 0.529) and 1RM SQ (r: 0.504 to 0.590) were significantly related to sprint performance. Therefore, young rugby players who present lower magnitudes of SDef and superior 1RM SQ performance tend to be faster in linear sprints.
... It has been reported that there is no difference in linear functions and second-order polynomial fits (1). However, some studies have shown that nonlinear functions can provide better fits than linear functions (9,17,21). Individualized fitting second-order polynomials equation with each load and MV was also used to predict the %1RM estimate. The individualized MV at 100% 1RM was used to predict the 1RM value. ...
Article
The aim of this study was to determine if bar velocity can be used to estimate the one-repetition maximum (1RM) on the hexagonal bar deadlift. Twenty-two NCAA Division I male ice hockey players (age= 21.0 ± 1.5 yrs, height= 182.9 ± 7.3 cm, body mass= 86.2 ± 7.3 kg) completed a progressive loading test using the hexagonal bar deadlift at maximum intended velocity to determine their 1RM. Mean concentric velocity (MV) was measured for each load via a linear position transducer. The a-priori alpha level of significance was set at p = 0.05. MV showed a very strong relationship to %1RM (R2 = 0.85). A non-significant difference and a trivial effect size (ES) were observed between actual and predicted 1RM (p = 0.90, ES = -0.08). Near-perfect correlations were also discovered between actual and predicted 1RM (R = 0.93) with low typical error and coefficient of variation (5.11 kg, 2.53%, respectively). The current study presented results that add the HBD to the list of exercises with established load-velocity relationships. The predictive ability for 1RM HBD indicates that this is a viable means of prediction of 1RM.
... Se encontró una correlación positiva entre la velocidad lineal de la barra (VMP) y la velocidad angular de la rodilla (VAR). Sin embargo, así como estudios previos [1] han demostrado que a una carga relativa al 1RM corresponde una VMP determinada, en el caso de la VAR difícilmente se podrá establecer esta relación directa debido a la variabilidad inter-sujeto probablemente a causa de factores antropométricos. Referencias: ...
Conference Paper
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Introducción: La velocidad de ejecución parece ser uno de los principales aspectos para el control de la carga de entrenamiento. El análisis del movimiento del deportista a partir de sensores inerciales en vez de la sensorización de las barras o máquinas de musculación podría ser una alternativa para el control de la velocidad de ejecución en una sesión de entrenamiento de la fuerza. El presente estudio tiene como objetivo contrastar la velocidad angular de la rodilla (VAR) a partir de un dispositivo inercial con la velocidad media propulsiva de la barra (VMP) en el ejercicio de sentadilla completa para su aplicación en el control de la carga de entrenamiento. Métodos: Un total de 8 sujetos (26±4,72 años, 75±19,6 kg) practicantes de CrossFit participaron en el estudio. Posteriormente a un calentamiento general y familiarización, se realizó una serie de 3 repeticiones a máxima velocidad concéntrica de sentadilla completa con dos cargas cercanas al teórico pico de potencia (60% y 70% 1RM). La VAR se midió a partir de un sistema inercial DyCare Lynx (Barcelona, España) y VMP a partir de un Encoder Lineal Chrono-Jump ® (Barcelona, España). La prueba se realizó con una barra guiada para asegurar el movimiento lineal de la barra. Resultados: En un total de 48 repeticiones se obtuvo una correlación positiva entre la VAR y la VMP (r=0.73; p<0.05). Además, se encontraron diferencias significativas en la VAR medida a partir de Lynx entre las cargas del 60% y 70% 1RM de sentadilla completa (diferencia 41,15 ± 14,15 º/s ; p<0.05). El Coeficiente de Variación intra-sujeto (CV) fue de un 9,6% en el caso de la VAR y de un 3,1% en la VMP. 70%1RM 60%1RM Tabla 1: Promedio de velocidad en cada una de las cargas valoradas por los dos sistemas. Lineal (m/s) 0,80±0,14 1,00±0,05 Angular (º/s) 136,17±26,17 177,32±29,59 Conclusiones: La VAR medida a partir del sistema inercial "Lynx" fue sensible a cambios de un 10% 1RM en el ejercicio de sentadilla completa realizado a la máxima velocidad, demostrando una variabilidad intra-sujeto (CV) por debajo del 10%. Se encontró una correlación positiva entre la velocidad lineal de la barra (VMP) y la velocidad angular de la rodilla (VAR). Sin embargo, así como estudios previos [1] han demostrado que a una carga relativa al 1RM corresponde una VMP determinada, en el caso de la VAR difícilmente se podrá establecer esta relación directa debido a la variabilidad inter-sujeto probablemente a causa de factores antropométricos.
... Currently, because of advances in technology that allow the execution velocity measurement in exercises with free weights, there is the possibility of determining/estimating, with a high degree of precision, the relative intensity (%1RM) that represents the absolute load lifted from the first (or fastest) repetition of the set, always performed at the maximum possible velocity [5,[25][26][27][28], all this through specific regression equations for each exercise. This result occurs because the mean propulsive velocity of the fastest repetition of the set is intrinsically associated with the relative load magnitude (%1RM), and therefore each %1RM has its velocity [5]. ...
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Nos estudos iniciais, que documentaram os efeitos positivos do treinamento com pesos e a execução de esforços musculares repetidos, o propósito da ciência de conhecer a melhor maneira de definir, controlar e dosar o treinamento de força tem sido uma das questões que concentraram o maior interesse e esforço. Trata-se de uma questão extremamente importante, pois os resultados originários dos trabalhos científicos de maior qualidade devem possibilitar a continuação da geração do corpo de conhecimento que ajuda a melhorar a metodologia do treinamento e, portanto, as participações na prática dos profissionais. Para que isso seja cumprido, os estudos científicos devem ter, entre outros atributos, um método preciso de determinação e controle das variáveis que definem o estímulo do treinamento proposto, a fim de verificar a relação entre ele e os efeitos produzidos. No entanto, se isso não acontecer, pesquisadores e profissionais do treinamento correm o risco de tomar decisões sobre a configuração dos estímulos (manipulação das variáveis da carga) com base em conclusões científicas "falsas" ou incertas, na melhor das hipóteses.
... In this sense several authors had mentioned that 1RM changes over days. Thus, that measurement is not feasible in the long term since athletes could achieve an overload easier, and they could get injuried (Gorostiaga et al., 2012;Sánchez-Medina et al., 2017). Aim: This study examined differences in 1RM between days, mechanical and metabolic fatigue, and risk of injury when bench press testing was performed over four consecutive days. ...
Conference Paper
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El deporte ecuestre sigue creciendo en popularidad, pero las investigaciones anteriores se refieren, por un lado, a las barreras relacionadas con las lesiones asociadas a este deporte, y por otro, a los beneficios de la equitación terapéutica para personas con discapacidad (MacKinnon & Laliberte, 1995). No existen muchos estudios acerca los beneficios para la salud y las barreras para la participación de las personas que no padecen estos trastornos (Koca, 2016). El propósito de analizar las relaciones causa-efecto de las mujeres que practican equitación, es comprender los niveles en los que la salud se ve afectada, abarcando el cuerpo y la mente de las participantes. 2540 mujeres jinetes (1827 amateurs y 713 profesionales) completaron el EBBS (Exercise Benefits/Barriers Scale) (Sechrist et al., 1987) el cual consta de 43 ítems, 29 ítems del constructo de beneficios y 14 ítems bajo el constructo barreras. Los beneficios para la salud con mayor puntuación media son: mejora de vida, rendimiento físico, interacción social y salud preventiva. En lo referido a las barreras: gasto de tiempo, esfuerzo físico, entorno de ejercicio y desánimo familiar. Existen fuertes correlaciones positivas entre casi todos los beneficios estando menos conectados rendimiento físico e interacción social. A diferencia de los beneficios, las barreras tienen muy poca correlación entre sí, y son casi independientes unas de otras. Entre las barreras y los beneficios hay correlaciones muy pequeñas o nulas. Respecto a la diferencia entre jinetes profesionales y amateurs, en los beneficios los profesionales obtienen mayores puntuaciones en esfuerzo físico y los amateurs en salud preventiva. En lo que respecta a las barreras, las jinetes profesionales puntúan más alto en gasto de tiempo y las amateurs en entorno de ejercicio y desánimo familiar. Una conclusión importante es que las participantes obtuvieron impacto positivo en el constructo beneficios para la salud.
... In this sense several authors had mentioned that 1RM changes over days. Thus, that measurement is not feasible in the long term since athletes could achieve an overload easier, and they could get injuried (Gorostiaga et al., 2012;Sánchez-Medina et al., 2017). Aim: This study examined differences in 1RM between days, mechanical and metabolic fatigue, and risk of injury when bench press testing was performed over four consecutive days. ...
Conference Paper
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Recreational running, or jogging has increased in recent years, becoming a global phenomenon (Scheerder et al., 2015). However, due to busy schedules and personal reasons, some of the participants tend to practice physical activity in the evening (Saleh et al., 2019). Despite amateur runners’ reason to participate has been widely analyzed, night runners’ motivational aspects remain unclear. Therefore, the aim of this research was to analyze night amateur athletes’ motivation to run. Data from 233 participants (52.8% male and 47.2% female) was collected, and to assess night runners’ motivations, the Polish translation of the motivations of marathoners’ scales (MOMS) created by Masters and Ogles was used (Dybała, 2013). Descriptive and relational statistics were carried out and results showed that five out of nine dimensions of MONS scale showed statistical differences gender wise (p < 0.001). Female scored higher in motivations related to weight concern, while male scored significantly higher in personal goal achievement, competition, recognition, and affiliation reasons to participate. Partially in concordance with previous research, we conclude that male night runners’ motivation is related to performance aspects (personal goal achievement and competition), and social aspects (recognition and affiliation), while female night runners show a higher motivation to run related to weight concern than male athletes. In conclusion, these results should be taken into account when promoting active lifestyles and night running participation.
... From this position, participants were then asked to perform the concentric phases as fast as possible. Initial load was set at 20 kg and was progressively increased in 10 kg increments until an MV of <0.6 m/s was reached, corresponding to ≈85% of 1RM [21]. MV was measured using the PUSH band ™ 2.0 (PUSH Inc., Toronto, Canada). ...
Article
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It has been suggested that sex differences exist in recovery following strength training. This study aimed to investigate the differences in recovery kinetics between resistance trained males and females following two different back squat (BSq) protocols. The first protocol (eight females and eight males) consisted of five sets of five repetitions at 80% of their one-repetition maximum (1RM) in the BSq (SMRT), while the second (seven females and eight males) consisted of five sets to muscular failure (MF) with a 4–6RM load (RMRT). The recovery was quantified with the mean concentric velocity (MV) at 80% of the 1RM immediately before and 5 min, 24, 48, and 72 h after the training protocol. Following the SMRT, a significant between-sex difference, favoring the females, was observed at 5 min, 24 h, and 48 h following the SMRT (p < 0.05, Effect Size (ES) = 1.01–2.25). Following the RMRT, only the males experienced a significant drop in performance after 5 min compared to the baseline (p = 0.025, ES = 1.34). However, no sex differences were observed at any timepoint (p > 0.05). These results suggest that males experienced more fatigue than females following a protocol where the volume relative to the 1RM was matched, while no differences in fatigue were evident following a protocol in which multiple sets were performed to MF.
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Strength and conditioning specialists commonly deal with the quantification and selection the setting of protocols regarding resistance training intensities. Although the one repetition maximum (1RM) method has been widely used to prescribe exercise intensity, the velocity-based training (VBT) method may enable a more optimal tool for better monitoring and planning of resistance training (RT) programs. The aim of this study was to compare the effects of two RT programs only differing in the training load prescription strategy (adjusting or not daily via VBT) with loads from 50 to 80% 1RM on 1RM, countermovement (CMJ) and sprint. Twenty-four male students with previous experience in RT were randomly assigned to two groups: adjusted loads (AL) ( n = 13) and non-adjusted loads (NAL) ( n = 11) and carried out an 8-week (16 sessions) RT program. The performance assessment pre- and post-training program included estimated 1RM and full load-velocity profile in the squat exercise; countermovement jump (CMJ); and 20-m sprint (T20). Relative intensity (RI) and mean propulsive velocity attained during each training session (V session ) was monitored. Subjects in the NAL group trained at a significantly faster V session than those in AL ( p < 0.001) (0.88–0.91 vs. 0.67–0.68 m/s, with a ∼15% RM gap between groups for the last sessions), and did not achieve the maximum programmed intensity (80% RM). Significant differences were detected in sessions 3–4, showing differences between programmed and performed V session and lower RI and velocity loss (VL) for the NAL compared to the AL group ( p < 0.05). Although both groups improved 1RM, CMJ and T20, NAL experienced greater and significant changes than AL (28.90 vs.12.70%, 16.10 vs. 7.90% and −1.99 vs. −0.95%, respectively). Load adjustment based on movement velocity is a useful way to control for highly individualised responses to training and improve the implementation of RT programs.
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This study aimed to: i) analyze the differences in anthropometric, body composition, physical, and technical parameters in elite female football players across distinct playing positions; ii) examine the correlations between kicking velocity (KV) and physical performance, and the relationships between linear sprint and curve sprint (CS) times. Twenty-six female players (n = 26, age: 27 ± 4 years) of an elite football team completed the following assessments: anthropometric, body-composition, squat one-repetition maximum (1RM), 30-m linear sprint, 17-m CS, vertical jump, endurance, and KV measurements. In terms of body composition, only muscle mass was significantly different (P = 0.046) in favour of forwards compared to midfielders. Regarding physical performance, overall, jump and sprint capacities were superior in defenders and forwards compared to midfielders (P < 0.05). Linear and CS times (P < 0.05, r = 0.450 to 0.573) and loads at 1 m/s in the squat (P < 0.05, r = 0.508) were significantly correlated to KV. Lastly, moderate to strong correlations were observed between linear and CS times (r = 0.396 to 0.916). In conclusion, in this international team, physical performance was higher for defenders and forwards compared to midfielders, especially in terms of sprint and jump abilities. Additionally, significant relationships were detected between strength-and speed-related qualities and KV.
Article
In this study, we aimed to analyze (i) the strength and power changes after resistance training (RT) in elite futsal players, and (ii) the associations between the session rate of perceived exertion (sRPE) and perceived total quality recovery (TQR), and the sRPE and TQR with the volume load of the RT program. Ten elite futsal players (24.8 ± 5.4 years; 76.2 ± 7.1 kg; 1.77 ± 0.05 m) performed an in-season 8-week RT program twice per week. RT consisted of 2-3 sets x 3-6 reps at 45-65% of one-repetition maximum (1RM) with maximal velocities in the full squat and complementary exercises with the same volume. We assessed the TQR before every session, while the sRPE was calculated after each RT session. One week before and after the intervention, we measured the countermovement jump (CMJ) height, isometric hip adduction strength (IHAS), 1RM, and peak power (PP) in the full squat progressive loading test. After the 8-week training program, there was a significant improvement in most outcomes, yet the gains (%Δ) remained below the minimal detectable change (MDC), except for IHAS (CMJ: p < 0.05, %Δ = 6.7, MDC% = 7.2; IHAS: p < 0.001, %Δ = 19.1, MDC% = 14.6; 1RM: p > 0.05, %Δ = 9.2, MDC% = 21.5; PP: p < 0.05; %Δ = 14.4, MDC% = 22.4). We also found a significant negative correlation between TQR and the sRPE (r = -0.45, p < 0.001). Our data suggest that RT based on low-volume and low-to-moderate loads may not produce a sufficient stimulus to induce meaningful dynamic strength and power gains in elite futsal players, although it improves isometric strength. Furthermore, monitoring TQR before sessions may show coaches how the elite futsal player will perceive the session's intensity.
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This study aimed to evaluate the reliability and the level of agreement of the ADR encoder to measure the mean propulsive velocity (MPV) of the bar in the bench press (BP) exercise on the Smith machine. Eleven males (21.6 ± 1.5 years; body mass 76.05 ± 9.73 kg) performed the protocol with isometric phase prior to concentric muscle action (PP) and the protocol in the absence of isometric phase (N-PP) for BP exercise on Smith machine. ADR encoder reported reliability values with almost perfect correlations in all training zones and protocols (PP: ICC = 0.940–0.999, r = 0.899–0.997, CV = 1.56%–4.05%, SEM = 0.0022–0.0153,and MDC = 0.006–0.031 m/s; N-PP: ICC = 0.963–0.999, r = 0.946–0.998, CV = 0.70%–3.01%, SEM = 0.0012–0.0099, and MDC = 0.003–0.027 m/s). Although the levels of agreement were high in both protocols (PP: SEM = 0.0024–0.0204 m/s, MDC = 0.007–0.057 m/s; N-PP: SEM = 0.0034–0.0288 m/s, MDC = 0.009–0.080 m/s), ADR encoder considerably underestimated the MPV values in both protocols (PP: t = −2.239 to −9.486, p < 0.001–0.01; N-PP: t = −6.901 to −17.871, p < 0.001) with respect to the gold standard (T-Force). In conclusion, ADR encoder offers high reliability for the measurement of MPV in bench press exercise performed on Smith machine regardless of their execution mode, in the entire range of intensities. However, this device is not interchangeable with T-Force since it considerably underestimates the MPV values, especially at low loads (0%–40%). Furthermore, the use of too wide load ranges suggests that the data be interpreted with caution, pending further research to corroborate the findings presented.
Thesis
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El cáncer es una de las principales causas de mortalidad en España, siendo el cáncer de mama el más diagnosticado en mujeres. La propia enfermedad y los tratamientos oncológicos producen distintos efectos secundarios, entre los que se encuentra la fatiga relativa al cáncer (CRF). Ésta, es una de las secuelas más prevalentes y que más afecta la vida diaria de las supervivientes de cáncer de mama. Con una etiología compleja, la CRF se desencadena por distintos mecanismos fisiológicos, por lo que su tratamiento puede requerir la aplicación de terapias tanto farmacológicas, como no farmacológicas. Entre las últimas, el ejercicio físico es la terapia más efectiva para reducir su impacto. De modo general, existe amplia evidencia sobre los beneficios que el ejercicio físico produce en pacientes y supervivientes de cáncer. Los efectos de entrenamientos de tipo aeróbico, entrenamiento de fuerza, actividades cuerpo-mente y/o actividades deportivas, son una creciente área de estudio, especialmente prolífica en supervivientes de cáncer de mama. Así, para la reducción de la CRF, existen guías específicas donde el ejercicio forma parte esencial del tratamiento. Aunque en ellas se propone la práctica de actividad física de tipo concurrente (incluyendo tanto entrenamiento aeróbico, como de fuerza), diversos autores apuntan que es preciso individualizar la prescripción de ejercicio físico. Esto se debe, en parte, al diferente nivel de tolerancia al ejercicio de los supervivientes de cáncer, que incluso puede resultar una barrera para la práctica de actividad física. Dentro de los diferentes tipos de entrenamiento, el entrenamiento de la musculatura inspiratoria (IMT), ha sido propuesto como una herramienta válida para la mejora de la condición física y la función pulmonar en pacientes de diversas patologías. Debido a su sencillez y viabilidad a la hora de implementarlo, y a su demostrado efecto sobre el aumento de la tolerancia al ejercicio, el IMT ha sido estudiado en personas con distintas patologías, incluyendo tumores intratorácicos y abdominales. En supervivientes de cáncer de mama (SCM), aunque el IMT no ha sido analizado en profundidad, se ha reconocido que podría mejorar la capacidad de ejercicio en esta población. Sin embargo, no se ha publicado ningún estudio que analice su efectividad en la reducción de la fatiga. Por otro lado, el nivel de actividad física (AF), ha sido asociado a la mejora de la calidad de vida (QoL) en supervivientes de cáncer y la reducción de la CRF. Por este motivo, el nivel de actividad física ha sido estudiado en cohortes de SCM españolas. Sin embargo, y a pesar de que sería interesante conocer el estado de dicha cuestión, se desconoce cuáles son los niveles actuales de actividad física y calidad de vida de las SCM españolas. Dada la importancia que tiene el nivel de actividad física sobre la CRF y la QoL, y debido al efecto que el IMT podría tener sobre este efecto secundario de las SCM, esta Tesis Doctoral fijó dos objetivos. En primer lugar, analizar los niveles de actividad física y QoL en una muestra representativa de la población de supervivientes de cáncer de mama españolas (Estudio 1). En segundo lugar, analizar el efecto del IMT sobre su CRF, capacidad funcional y tolerancia al esfuerzo (Estudio 2). Para el primer objetivo (Estudio 1), se administraron dos cuestionarios a la población objetivo a través del contacto con distintas asociaciones de pacientes y entidades relacionadas. Uno para el registro de datos sobre patrón de AF (HUNT1-PAQ), y otro, específico para evaluar la QoL en supervivientes de cáncer de mama (FACT-B). Una vez se alcanzó el número de respuestas que se había considerado mínimo para que la muestra fuera representativa de la población española de SCM, se realizó un análisis descriptivo de los resultados. Para el segundo objetivo (Estudio 2) se realizó una intervención experimental, en el que se aplicó, a SCM, un programa de ejercicio, en el que se combinó un programa de IMT con un entrenamiento de fuerza con cargas ligeras. Las participantes, fueron asignadas a un grupo intervención (realizando el IMT) y un grupo placebo, realizando todas ellas el entrenamiento de fuerza. Entre las valoraciones seleccionadas, se administró un cuestionario específico de análisis del nivel de fatiga (FACIT-F). El Estudio 1 reveló que las supervivientes de cáncer de mama españolas, no cumplían con las recomendaciones mínimas de actividad física propuestas por las principales organizaciones internacionales. Por otro lado, el análisis de correlaciones realizado, mostró que el índice de masa corporal (IMC) y la intensidad del ejercicio, eran las variables más relacionadas con la QoL de las SCM españolas. Adicionalmente, se propuso el cuestionario HUNT1-PAQ como herramienta de fácil aplicación, en el ámbito clínico, para evaluar el nivel de actividad física de las supervivientes de cáncer de mama. Finalmente, los resultados del Estudio 2 mostraron un incremento en la puntuación del cuestionario FACIT-F en el grupo experimental, que había modificado su presión inspiratoria máxima tras 6 semanas de IMT. Esto muestra que el IMT es una herramienta segura, viable y efectiva en la reducción del nivel de CRF de las supervivientes de cáncer de mama.
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Introduction Movement velocity (MV) has been featured as a more accurate and stable variable for resistance exercise (RE) monitoring. However, its application in RE prescription based on self-selected MV (MVss) is not possible because the benefits were evaluated only in the maximal intended MV practice context. Thus, the objective of this study was to verify the validity and reliability of MVss as a performance measure in RE. Methods A group of 41 people (28.75 ± 10.06 years, 77.25 ± 9.04 kg, 1.76 ± 0.06 m for men and 30.25 ± 15.97 years, 62.96 ± 14.31 kg, 1.65 ± 0.06 for women) volunteered to participate in this study, and their performances were evaluated in knee extension and close grip pull-down, using a rotary position transducer. Results In fact, the results presented evidence of concurrent validity of MVss, although its predictive validity must be questioned (R² = 0.5; P < 0.05). Moreover, two points of performance transitions seem to exist, which could characterize three distinct zones of effort. Additionally, performances in both RE presented reasonable indicatives of reliability in consecutive evaluations (typical error = 0.05–0.07 m/s), suggesting the existence of minimal MVss thresholds. Despite the positive analyses of validity and reliability, practical applications of the MVss thresholds proposed here should be viewed with caution for RE monitoring in the individual context, taking into account the real capability to discriminate maximal and submaximal performances not supported by average-based comparisons.
Chapter
Resistance training (RT) is one of the most popular methods of exercise for improving physical fitness. The current interest in RT by women is evidenced by the great number of women who now train and the growth of female training contests. It is well documented that long-term systematic RT causes increased muscle strength and cardiovascular function. Regarding women, evidence has shown other related benefits such as an increased bone mineral density, improvements in maternal health and perinatal outcomes during pregnancy, changes in body composition, improvements in health-related outcomes in old age, and the treatment and risk reduction for multiple chronic diseases. In this chapter, we will cover the importance of RT training in women and its associated increase in general physical fitness and so in quality of life. We will describe the physiological mechanisms related to resistance training in women, and some gender differences. We will also describe the main effects and characteristics of RT programs in women, and focus on the potential benefits of resistance exercise during pregnancy and post-partum. Finally, we will try to provide some recommendations specific to women RT based on current research.
Article
Purpose: To compare the strength and athletic adaptations induced by 4 programming models. Methods: Fifty-two men were allocated into 1 of the following models: linear programming (intensity increased while intraset volume decreased), undulating programming (intensity and intraset volume were varied in each session or set of sessions), reverse programming (intensity decreased while intraset volume increased), or constant programming (intensity and intraset volume kept constant throughout the training plan). All groups completed a 10-week resistance-training program made up of the free-weight bench press, squat, deadlift, prone bench pull, and shoulder press exercises. The 4 models used the same frequency (2 sessions per week), number of sets (3 per exercise), interset recoveries (4 min), and average intensity throughout the intervention (77.5%). The velocity-based method was used to accurately adjust the planned intensity for each model. Results: The 4 programming models exhibited significant pre-post changes in most strength variables analyzed. When considering the effect sizes for the 5 exercises trained, we observed that the undulating programming (mean effect size = 0.88-2.92) and constant programming (mean effect size = 0.61-1.65) models induced the highest and lowest strength enhancements, respectively. Moreover, the 4 programming models were found to be effective to improve performance during shorter (jump and sprint tests) and longer (upper- and lower-limb Wingate test) anaerobic tasks, with no significant differences between them. Conclusion: The linear, undulating, reverse, and constant programming models are similarly effective to improve strength and athletic performance when they are implemented in a real-context routine.
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Chapter
Currently, velocity-based training (VBT) is one of the hot topics in sport science and among strength and conditioning coaches. However, its wide use has spread some misunderstandings of the fundamental concepts of this methodology. It should be highlighted that this is not a new training method, but rather, a new approach that enables more accurate, frequent, and objective control of resistance training intensity and volume. The VBT approach is no other thing than recording lifting velocity every repetition during resistance training. The quantification of actual repetition velocities achieved during resistance training sessions provides a more consistent and precise understanding of training effects, opening up the possibility to establish causal relationships between stimuli and response, which is one of the main and most important targets of research and practice in sport science. As such, VBT can be defined as a resistance training method that uses movement velocity to improve training process and enhance training effects, via a deeper understanding of the input signal (actual training load) and the output signal (changes in performance). Through this chapter we will see how VBT contributes to improve the resistance training methodology, as well as discuss its potential benefits, limitations, and practical implications.
Experiment Findings
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Durante 6 semanas, un grupo de mujeres supervivientes de cáncer de mama (n = 10) realizaron IMT junto con un protocolo de ejercicio de fuerza con cargas ligeras (gomas elásticas). El grupo control (n=10) realizaba tan sólo el entrenamiento de cargas.
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Purpose: The purpose of this study was to investigate the influence of relative strength levels on load-velocity relationships in the back squat (BS). Methods: Healthy male participants (N=18) experienced in the BS performed at relative intensity (as %1RM) intervals of their estimated one-repetition maximum (1RM) up to their maximal effort. Participants were then grouped according to relative strength (1RM/body mass) into weak or strong. A comparison was made using a 2x8 (group by relative intensity) repeated-measures analysis of variance (RM-ANOVA) to identify group effects and intensity zone effect on mean concentric velocity (MCV) of the BS. Results: A significant within-subjects difference was shown between weak vs. strong [F(2.973,57.568) = 298.604, p < .001]. However, contrary to what was hypothesized, weaker participants tended to perform at higher velocities across all intensity zones. Group difference on MCV was different in trend, but not found as significance [F(1,16) = 3.212, p = .092]. Conclusion: Although group difference was not found as significant effect, strength and conditioning professionals should be advised that velocity characteristics of the BS may differ between individuals of different strength levels throughout %1RM ranges. Periodic testing and monitoring of individual athletes may be required in order to capture physical gain due to strength improvement and use of velocity as a tool for training prescription.
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Aim: To analyze the effects of two resistance training (RT) programs that used the same relative loading but different repetition volume, using the velocity loss during the set as the independent variable: 15% (VL15) vs. 30% (VL30). Methods: Sixteen professional soccer players with RT experience (age 23.8 ± 3.5 years, body mass 75.5 ± 8.6 kg) were randomly assigned to two groups: VL15 (n = 8) or VL30 (n = 8) that followed a 6-week (18 sessions) velocity-based squat training program. Repetition velocity was monitored in all sessions. Assessments performed before (Pre) and after training (Post) included: estimated one-repetition maximum (1RM) and change in average mean propulsive velocity (AMPV) against absolute loads common to Pre and Post tests; countermovement jump (CMJ); 30-m sprint (T30); and Yo-yo intermittent recovery test (YYIRT). Null-hypothesis significance testing and magnitude-based inference statistical analyses were performed. Results: VL15 obtained greater gains in CMJ height than VL30 (P < 0.05), with no significant differences between groups for the remaining variables. VL15 showed a likely/possibly positive effect on 1RM (91/9/0%), AMPV (73/25/2%) and CMJ (87/12/1%), whereas VL30 showed possibly/unclear positive effects on 1RM (65/33/2%) and AMPV (46/36/18%) and possibly negative effects on CMJ (4/38/57%). The effects on T30 performance were unclear/unlikely for both groups, whereas both groups showed most likely/likely positive effects on YYIRT. Conclusions: A velocity-based RT program characterized by a low degree of fatigue (15% velocity loss in each set) is effective to induce improvements in neuromuscular performance in professional soccer players with previous RT experience.
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Purpose: The aim of this study was to determine whether athletes from different sports disciplines present similar mean propulsive velocity (MPV) in the half-squat (HS) during submaximal and maximal tests, enabling prediction of 1 repetition maximum (1-RM) from MPV at any given submaximal load. Methods: Sixty-four male athletes, comprising American football, rugby and soccer players, sprinters and jumpers, and combat sports strikers, attended two testing sessions separated by 2-4 weeks. On the first visit, a standardized 1-RM test was performed. On the second visit, athletes performed HS on the Smith-machine equipment, using relative percentages of 1-RM in order to determine the respective MPV of submaximal and maximal loads. Linear regression established the relationship between MPV and percentage of 1-RM. Results: A very strong linear relationship (R2 ≈ 0.96) was observed between the MPV and the percentages of HS 1-RM, resulting in the following equation: % of HS 1-RM = -105.05 · MPV + 131.75. The MPV at HS 1-RM was ≈ 0.3 m·s-1. Conclusion: This equation can be used to predict the HS 1-RM on the Smith-machine equipment with a high degree of accuracy.
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The purpose of this study was to investigate the relationship between movement velocity and relative load in three lower limbs exercises commonly used to develop strength: leg press, full squat and half squat. The percentage of one repetition maximum (%1RM) has typically been used as the main parameter to control resistance training; however, more recent research has proposed movement velocity as an alternative. Fifteen participants performed a load progression with a range of loads until they reached their 1RM. Maximum instantaneous velocity (Vmax) and mean propulsive velocity (MPV) of the knee extension phase of each exercise were assessed. For all exercises, a strong relationship between Vmax and the %1RM was found: leg press (r(2)adj = 0.96; 95% CI for slope is [-0.0244, -0.0258], P < 0.0001), full squat (r(2)adj = 0.94; 95% CI for slope is [-0.0144, -0.0139], P < 0.0001) and half squat (r(2)adj = 0.97; 95% CI for slope is [-0.0135, -0.00143], P < 0.0001); for MPV, leg press (r(2)adj = 0.96; 95% CI for slope is [-0.0169, -0.0175], P < 0.0001, full squat (r(2)adj = 0.95; 95% CI for slope is [-0.0136, -0.0128], P < 0.0001) and half squat (r(2)adj = 0.96; 95% CI for slope is [-0.0116, 0.0124], P < 0.0001). The 1RM was attained with a MPV and Vmax of 0.21 ± 0.06 m s(-1) and 0.63 ± 0.15 m s(-1), 0.29 ± 0.05 m s(-1) and 0.89 ± 0.17 m s(-1), 0.33 ± 0.05 m s(-1) and 0.95 ± 0.13 m s(-1) for leg press, full squat and half squat, respectively. Results indicate that it is possible to determine an exercise-specific %1RM by measuring movement velocity for that exercise.
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The purpose of this study was to analyze the effects of a low-load, high-velocity resistance training (RT) combined with plyometrics on physical performance in pre-peak height velocity (PHV) soccer players. Thirty young soccer players from the same academy were randomly assigned to either a strength training (STG, n = 15) or a control group (CG, n = 15). Strength training consisted of full squat exercise with low-load (45-58% 1RM) and low-volume (4-8 repetitions per set) combined with jumps and sprints twice a week over 6 weeks of preseason. The effect of the training protocol was assessed using sprint performance over 10 and 20 m (T10, T20, T10-20), countermovement jump (CMJ), estimated one-repetition maximum (1RMest) and average velocity attained against all loads common to pre- and post-tests (AV) in full squat. STG showed significant improvements (P = .004 - .001) and moderate to very large standardized effects (ES = 0.71 - 2.10) in all variables measured, whereas no significant gains were found in CG (ES = -0.29 to 0.06). Moreover, significant test × group interactions (P < .003 - .001) and greater between-groups ES (0.90 - 1.97) were found for all variables in favour of STG compared to CG. Only 6 weeks of preseason low-volume and low-loads RT combined with plyometrics can lead to relevant improvements in strength, jump and sprint performance. Thus, the combination of field soccer training and lightweight strength training could be used for a greater development of the tasks critical to soccer performance in pre-PHV soccer players.
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This study aimed to determine the effects of combined resistance training and plyometrics on physical performance in under-15 soccer players. One team (n=20) followed a 6-week resistance training program combined with plyometrics plus a soccer training program (STG), whereas another team (n=18) followed only the soccer training (CG). Strength training consisted of full squats with low load (45-60% 1RM) and low-volume (2-3 sets and 4-8 repetitions per set) combined with jumps and sprints twice a week. Sprint time in 10 and 20 m (T10, T20, T10-20), CMJ height, estimated one-repetition maximum (1RMest), average velocity attained against all loads common to pre- and post-tests (AV) and velocity developed against different absolute loads (MPV20, 30, 40 and 50) in full squat were selected as testing variables to evaluate the effects of the training program. STG experienced greater gains (P<0.05) in T20, CMJ, 1RMest, AV and MPV20, 30, 40 and 50 than CG. In addition, STG showed likely greater effects in T10 and T10-20 compared to CG. These results indicate that only 6 weeks of resistance training combined with plyometrics in addition to soccer training produce greater gains in physical performance than typical soccer training alone in young soccer players. © Georg Thieme Verlag KG Stuttgart · New York.
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This study aimed to analyze the effect of velocity based-resistance training (RT) with moderate load and few repetitions per set combined with jumps and sprints on physical performance in young soccer players of different ages. A total of 44 elite youth soccer players belonging to three teams participated in this study: an under-16 team (U16, n = 17) and an under-18 team (U18, n = 16) performed maximal velocity RT program for 26 weeks in addition to typical soccer training, whereas an under-21 team (U21, n = 11) did not perform RT. Before and after the training program all players performed: 20-m running sprint (T20); countermovement jump (CMJ); a progressive isoinertial loading test in squat to determine the load which players elicited ∼1 m·s (V1LOAD); and an incremental field test to determine maximal aerobic speed (MAS). U16 showed significantly (P = .000) greater gains for V1LOAD than U18 and U21 (100/0/0%). Only U16 showed significantly (P = .01) greater gains than U21 (99/1/0%) for CMJ height. U18 obtained a likely better effect on CMJ performance than U21 (89/10/1%). The beneficial effects on T20 between groups were unclear. U16 showed a likely better effect on MAS than U21 (80/17/3%), whereas the rest of comparisons were unclear. The changes in CMJ correlated to the changes in T20 (r = -.49) and V1LOAD (r = .40). In conclusion, velocity-based RT with moderate load and few repetitions per set seems to be an adequate methodology to improve the physical performance in young soccer players.
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The purpose of this study was to determine the effects of two different strength-power training models on sprint performance. Forty-eight soldiers of the Brazilian brigade of special operations with at least one year of army training experience were divided into a control group (CG: n = 15, age: 20.2 ± 0.7 years, body height: 1.74 ± 0.06 m, and body mass: 66.7 ± 9.8 kg), a traditional training group (TT: n = 18, age: 20.1 ± 0.7 years, body height: 1.71 ± 0.05 m, and body mass: 64.2 ± 4.7 kg), and a complex training group (CT: n = 15, age: 20.3 ± 0.8 years, body height: 1.71 ± 0.07 m; and body mass: 64.0 ± 8.8 kg). Maximum strength (25% and 26%), CMJ height (36% and 39%), mean power (30% and 35%) and mean propulsive power (22% and 28%) in the loaded jump squat exercise, and 20-m sprint speed (16% and 14%) increased significantly (p≤0.05) following the TT and CT, respectively. However, the transfer effect coefficients (TEC) of strength and power performances to 20-m sprint performance following the TT were greater than the CT throughout the 9-week training period. Our data suggest that TT is more effective than CT to improve sprint performance in moderately trained subjects.
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This study aimed to compare the effect on neuromuscular performance of 2 isoinertial resistance training programs that differed only in actual repetition velocity: maximal intended (MaxV) vs. half-maximal (HalfV) concentric velocity. 21 resistance-trained young men were randomly assigned to a MaxV (n=10) or HalfV (n=11) group and trained for 6 weeks using the full squat exercise. A complementary study (n=8) described the acute metabolic and mechanical response to the protocols used. MaxV training resulted in a likely more beneficial effect than HalfV on squat performance: maximum strength (ES: 0.94 vs. 0.54), velocity developed against all (ES: 1.76 vs. 0.88), light (ES: 1.76 vs. 0.75) and heavy (ES: 2.03 vs. 1.64) loads common to pre- and post-tests, and CMJ height (ES: 0.63 vs. 0.15). The effect on 20-m sprint was unclear, however. Both groups attained the greatest improvements in squat performance at their training velocities. Movement velocity seemed to be of greater importance than time under tension for inducing strength adaptations. Slightly higher metabolic stress (blood lactate and ammonia) and CMJ height loss were found for MaxV vs. HalfV, while metabolite levels were low to moderate for both conditions. MaxV may provide a superior stimulus for inducing adaptations directed towards improving athletic performance.
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To determine whether the ergogenic effects of caffeine ingestion on neuromuscular performance are similar when ingestion takes place in the morning and in the afternoon. Double blind, cross-over, randomized, placebo controlled design. Thirteen resistance-trained males carried out bench press and full squat exercises against four incremental loads (25%, 50%, 75% and 90% 1RM), at maximal velocity. Trials took place 60min after ingesting either 6mgkg(-1) of caffeine or placebo. Two trials took place in the morning (AMPLAC and AMCAFF) and two in the afternoon (PMPLAC and PMCAFF), all separated by 36-48h. Tympanic temperature, plasma caffeine concentration and side-effects were measured. Plasma caffeine increased similarly during AMCAFF and PMCAFF. Tympanic temperature was lower in the mornings without caffeine effects (36.7±0.4 vs. 37.0±0.5°C for AM vs. PM; p<0.05). AMCAFF increased propulsive velocity above AMPLAC to levels similar to those found in the PM trials for the 25%, 50%, 75% 1RM loads in the SQ exercise (5.4-8.1%; p<0.05). However, in the PM trials, caffeine ingestion did not improve propulsive velocity at any load during BP or SQ. The negative side effects of caffeine were more prevalent in the afternoon trials (13 vs. 26%). The ingestion of a moderate dose of caffeine counteracts the muscle contraction velocity declines observed in the morning against a wide range of loads. Caffeine effects are more evident in the lower body musculature. Evening caffeine ingestion not only has little effect on neuromuscular performance, but increases the rate of negative side-effects reported.
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Abstract The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity. Twenty participants were assigned to a MaxV (n = 9) or HalfV (n = 11) group and trained 3 times per week during 6 weeks using the bench press (BP). Repetition velocity was controlled using a linear velocity transducer. A complementary study (n = 10) aimed to analyse whether the acute metabolic (blood lactate and ammonia) and mechanical response (velocity loss) was different between the MaxV and HalfV protocols used. Both groups improved strength performance from pre- to post-training, but MaxV resulted in significantly greater gains than HalfV in all variables analysed: one-repetition maximum (1RM) strength (18.2 vs. 9.7%), velocity developed against all (20.8 vs. 10.0%), light (11.5 vs. 4.5%) and heavy (36.2 vs. 17.3%) loads common to pre- and post-tests. Light and heavy loads were identified with those moved faster or slower than 0.80 m·s(-1) (∼60% 1RM in BP). Lactate tended to be significantly higher for MaxV vs. HalfV, with no differences observed for ammonia which was within resting values. Both groups obtained the greatest improvements at the training velocities (≤0.80 m·s(-1)). Movement velocity can be considered a fundamental component of RT intensity, since, for a given %1RM, the velocity at which loads are lifted largely determines the resulting training effect. BP strength gains can be maximised when repetitions are performed at maximal intended velocity.
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Purpose: The purpose of this study was to determine the oral dose of caffeine needed to increase muscle force and power output during all-out single multijoint movements. Methods: Thirteen resistance-trained men underwent a battery of muscle strength and power tests in a randomized, double-blind, crossover design, under four different conditions: (a) placebo ingestion (PLAC) or with caffeine ingestion at doses of (b) 3 mg · kg(-1) body weight (CAFF 3mg), (c) 6 mg · kg(-1) (CAFF 6mg), and (d) 9 mg · kg(-1) (CAFF 9mg). The muscle strength and power tests consisted in the measurement of bar displacement velocity and muscle power output during free-weight full-squat (SQ) and bench press (BP) exercises against four incremental loads (25%, 50%, 75%, and 90% one-repetition maximum [1RM]). Cycling peak power output was measured using a 4-s inertial load test. Caffeine side effects were evaluated at the end of each trial and 24 h later. Results: Mean propulsive velocity at light loads (25%-50% 1RM) increased significantly above PLAC for all caffeine doses (5.4%-8.5%, P = 0.039-0.003). At the medium load (75% 1RM), CAFF 3mg did not improve SQ or BP muscle power or BP velocity. CAFF 9mg was needed to enhance BP velocity and SQ power at the heaviest load (90% 1RM) and cycling peak power output (6.8%-11.7%, P = 0.03-0.05). The CAFF 9mg trial drastically increased the frequency of the adverse side effects (15%-62%). Conclusions: The ergogenic dose of caffeine required to enhance neuromuscular performance during a single all-out contraction depends on the magnitude of load used. A dose of 3 mg · kg(-1) is enough to improve high-velocity muscle actions against low loads, whereas a higher caffeine dose (9 mg · kg(-1)) is necessary against high loads, despite the appearance of adverse side effects.
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