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Abstract

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.
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... From this, mean and peak velocity are the most investigated outputs. The CV from these Optic devices Velowin Courel-Ibanez et al. [36], Peña Garcia-Orea et al. [82], Peña Garcia-Orea et al. [72], Garcia-Ramos et al. [71], Laza-Cagigas et al. [68], Perez-Castilla et al. [10] Courel-Ibanez et al. [36], Peña Garcia-Orea et al. [82], Peña Garcia-Orea et al. [72], Garcia-Ramos et al. [71], Perez-Castilla et al. [10] Flex Weakley et al. [22] Weakley et al. [22] 47,60,63]. This may be an issue for practitioners as mean concentric velocity is often advised for monitoring resistance training adaptations in non-ballistic exercises (e.g., squats, bench press) [64-66]. ...
... From this, mean and peak velocity are the most investigated outputs. The CV from these Optic devices Velowin Courel-Ibanez et al. [36], Peña Garcia-Orea et al. [82], Peña Garcia-Orea et al. [72], Garcia-Ramos et al. [71], Laza-Cagigas et al. [68], Perez-Castilla et al. [10] Courel-Ibanez et al. [36], Peña Garcia-Orea et al. [82], Peña Garcia-Orea et al. [72], Garcia-Ramos et al. [71], Perez-Castilla et al. [10] Flex Weakley et al. [22] Weakley et al. [22] 47,60,63]. This may be an issue for practitioners as mean concentric velocity is often advised for monitoring resistance training adaptations in non-ballistic exercises (e.g., squats, bench press) [64-66]. ...
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Background Monitoring resistance training has a range of unique difficulties due to differences in physical characteristics and capacity between athletes, and the indoor environment in which it often occurs. Traditionally, methods such as volume load have been used, but these have inherent flaws. In recent times, numerous portable and affordable devices have been made available that purport to accurately and reliably measure kinetic and kinematic outputs, potentially offering practitioners a means of measuring resistance training loads with confidence. However, a thorough and systematic review of the literature describing the reliability and validity of these devices has yet to be undertaken, which may lead to uncertainty from practitioners on the utility of these devices. Objective A systematic review of studies that investigate the validity and/or reliability of commercially available devices that quantify kinetic and kinematic outputs during resistance training. Methods Following PRISMA guidelines, a systematic search of SPORTDiscus, Web of Science, and Medline was performed; studies included were (1) original research investigations; (2) full-text articles written in English; (3) published in a peer-reviewed academic journal; and (4) assessed the validity and/or reliability of commercially available portable devices that quantify resistance training exercises. Results A total of 129 studies were retrieved, of which 47 were duplicates. The titles and abstracts of 82 studies were screened and the full text of 40 manuscripts were assessed. A total of 31 studies met the inclusion criteria. Additional 13 studies, identified via reference list assessment, were included. Therefore, a total of 44 studies were included in this review. Conclusion Most of the studies within this review did not utilise a gold-standard criterion measure when assessing validity. This has likely led to under or overreporting of error for certain devices. Furthermore, studies that have quantified intra-device reliability have often failed to distinguish between technological and biological variability which has likely altered the true precision of each device. However, it appears linear transducers which have greater accuracy and reliability compared to other forms of device. Future research should endeavour to utilise gold-standard criterion measures across a broader range of exercises (including weightlifting movements) and relative loads.
... Thus, the two ends of the bar were fixed, allowing only the vertical movement of the bar. To estimate the execution velocity of each repetition in the different tests, a previously validated optoelectronic instrument [22] was used, with a sampling frequency of 500 Hz (Velowin v.1.7.232, Instrumentos y Tecnología Deportiva; Murcia, Spain). ...
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Background: The aim of this study was to verify the reproducibility of a resistance training protocol in the bench press (BP) exercise, based on traditional recommendations, analysing the effect of the muscle fatigue of each set and of the whole exercise protocol. Methods: In this cross-sectional study, thirty male physical education students were divided into three groups according to their relative strength ratio (RSR), and they performed a 1RM BP test (T1). In the second session (T2), which was one week after T1, the participants performed a BP exercise protocol of three sets with the maximum number of repetitions (MNR) possible to muscle failure, using a relative load corresponding to 70% 1RM determined through the mean propulsive velocity (MPV) obtained from the individual load-velocity relationship, with 2 min rests between sets. Two weeks later, a third session (T3) identical to the second session (T2) was performed. The MPV of each repetition of each set and the blood lactate level after each set were calculated, and mechanical fatigue was quantified through the velocity loss percentage of the set (% loss MPV) and in a pre-post exercise test with an individual load that could be lifted at ~1 m·s-1 of MPV. Results: The number of repetitions performed in each set was significantly different (MNR for the total group of participants: set 1 = 12.50 ± 2.19 repetitions, set 2 = 6.06 ± 1.98 repetitions and set 3 = 4.20 ± 1.99 repetitions), showing high variation coefficients in each of the sets and between groups according to RSR. There were significant differences also in MPVrep Best (set 1 = 0.62 ± 0.10 m·s-1, set 2 = 0.42 ± 0.07 m·s-1, set 3 = 0.36 ± 0.10 m·s-1), which significantly reduced the % loss MPV of all sets (set 1 = 77.4%, set 2 = 64%, set 3 = 54.2%). The lactate levels increased significantly (p < 0.05) (set 1 = 4.9 mmo·L-1, set 2 = 6 mmo·L-1, set 3 = 6.5 mmo·L-1), and MPV loss at 1 m·s-1 after performing the three sets was 36% in T2 and 34% in T3, with acceptable intrasubject variability (MPV at 1 m·s-1 pre-exercise: SEM ≤ 0.09 m·s-1, CV = 9.8%; MPV at 1 m·s-1 post-exercise: SEM ≤ 0.07 m·s-1, CV = 11.7%). Conclusions: These exercise propositions are difficult to reproduce and apply. Moreover, the number of repetitions performed in each set was significantly different, which makes it difficult to define and control the intensity of the exercise. Lastly, the fatigue generated in each set could have an individual response depending on the capacity of each subject to recover from the preceding maximum effort.
... In this set-up, both ends of the barbell are fixed allowing only vertical movement of the bar. To estimate the execution velocity of each repetition in different tests, a previously validated opto-electronic instrument was used [24] with a sampling frequency of 500 Hz (Velowin v.1.7.232, Instruments and Sports Technology; Murcia, Spain). ...
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Citation: Maté-Muñoz, J.L.; Garnacho-Castaño, M.V.; Hernández-Lougedo, J.; Maicas-Pérez, L.; Notario-Alonso, R.; Da Silva-Grigoletto, M.E.; García-Fernández, P.; Heredia-Elvar, J.R. Analysis of the Use and Applicability of Different Variables for the Prescription of Relative Intensity in Bench Press Exercise. Biology 2022, 11, 336. https://
... Beyond other studies can complement and ratify the results obtained in ours (Peña García-Orea et al., 2019), the authors of the original study fail to understand the purpose and scientific contribution of the letter to the editor, especially when their authors do not question the reliability of the Velowin device and our results do not contradict others published in this regard (Courel-Ibañez et al., 2019;Laza-Cagigas et al., 2018;Peña García-Orea, Belando-Pedreño, Merino-Barrero, Jiménez-Ruiz, & Heredia-Elvar, 2018). For this reason, we suggest its authors to continue their research work and do not discredit the review process of this prestigious journal. ...
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The ‘letter to the Editor’ is supposedly a means to advance scientific knowledge and, therefore, it will always be well received. Although Bautista & Mart n did not request us to respond to their letter to the editor (Bautista & Mart n, 2019) in regard to our recently published article in this journal (Pe a Garc a-Orea, Belando-Pedre o, Merino-Barrero, & Heredia-Elvar, 2019), we would like to do so, as well as request them to cite the first surname of its first author. Our study aimed to analyse the reliability and validity of the Velowin opto-electronic device for assessment of the bar-velocity in the deep squat exercise performed on a Smith machine. For this purpose, a linear velocity transducer (T-Force) was taken as a gold standard with which to compare the velocity measurements. This technology (gold standard) is considered a very reliable and sensitive instrument for measuring bar velocity (Courel-Iba ez et al., 2019; S nchez-Medina & Gonz lez-Badillo, 2011). Next, we will respond to the allegations concerning to the different sections of our original study on which the authors of the letter to the editor give their opinion. Their letter to the editor not only questions different aspects related to the research design, statistical analysis and results of our study, but also the review process itself of a very well recognised journal. We believe that, if the alleged mistakes made and the results presented in the manuscript did not support the conclusions reached, the reviewers would have been as capable as the authors of the letter to the editor to detect them or reject the article.
... Beyond other studies can complement and ratify the results obtained in ours (Peña García-Orea et al., 2019), the authors of the original study fail to understand the purpose and scientific contribution of the letter to the editor, especially when their authors do not question the reliability of the Velowin device and our results do not contradict others published in this regard (Courel-Ibañez et al., 2019;Laza-Cagigas et al., 2018;Peña García-Orea, Belando-Pedreño, Merino-Barrero, Jiménez-Ruiz, & Heredia-Elvar, 2018). For this reason, we suggest its authors to continue their research work and do not discredit the review process of this prestigious journal. ...
... We have read with great interest and care the study carried out by García-Orea, Belando-Pedreño, Merino-Barrero, and Heredia-Elvar (2019) entitled 'Validation of an opto-electronic instrument for the measurement of execution velocity in squat exercise' DOI: 10.1080/14763141.2019.1597156. We applaud the authors for their thoughtful approach to the study. ...
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We have read with great interest and care the study carried out by García-Orea, Belando-Pedreño, Merino-Barrero, and Heredia-Elvar (2019 García-Orea, G. P., Belando-Pedreño, N., Merino-Barrero, J. A., & Heredia-Elvar, J. R. (2019) Validation of an opto-electronic instrument for the measurement of execution velocity in squat exercise. Sports Biomechanics. doi:10.1080/14763141.2019.1597156 [Taylor & Francis Online], , [Google Scholar] ) entitled ‘Validation of an opto-electronic instrument for the measurement of execution velocity in squat exercise’ DOI: 10.1080/14763141.2019.1597156. We applaud the authors for their thoughtful approach to the study. The general idea of the study is good and has an important practical utility, unfortunately there are some aspects, regarding both statistics and results that, in our modest opinion, need to be addressed.
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Introducción: en la evaluación de la utilidad de una prueba diagnóstica, se requiere en algunas situaciones valorar la reproducibilidad de los resultados o la concordancia de los mismos al compararla con otra prueba que no sea usada como patrón de oro de la entidad. El objetivo de este documento es presentar los métodos estadísticos utilizados para evaluar la reproducibilidad y/o concordancia de las observaciones clínicas o paraclínicas, sus bases teóricas y algunos ejemplos de cómo se han aplicado. Metodología: se realiza una revisión sobre las bases teóricas de la evaluación de la concordancia y la reproducibilidad, además se ilustra su aplicación en la literatura con ejemplos relacionados con la obstetricia y la ginecología. Resultados: la estimación de la concordancia se hace por medio de la prueba Kappa en variables dicotómicas u ordinales. En el caso de variables continuas, se debe preferir el uso del coeficiente de correlación intraclase o el coeficiente de correlación y concordancia sobre el uso del coeficiente de Pearson o la prueba t de Student pareada. Los métodos utilizados deben ser interpretados de acuerdo al contexto clínico donde fueron empleados. Conclusiones: la selección de los métodos estadísticos para la evaluación de la concordancia y la reproducibilidad depende del tipo de variable a medir y de los parámetros que se quieran evaluar, ya sea sólo la reproducibilidad o también la exactitud.
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The objective of this study was to explore the reliability and concurrent validity of the Velowin optoelectronic system to measure movement velocity during the free-weight back squat exercise. Thirty-one men (age = 27.5 ± 3.2 years; body height = 1.76 ± 0.15 m; body mass: 78.3 ± 7.6 kg) were evaluated in a single session against five different loads (20, 40, 50, 60 and 70 kg) and three velocity variables (mean velocity [MV], mean propulsive velocity [MPV] and maximum velocity [Vmax]) were recorded simultaneously by a linear velocity transducer (T-Force; gold-standard) and a camera-based optoelectronic system (Velowin). The main findings revealed that (1) the three velocity variables were determined with a high and comparable reliability by both the T-Force and Velowin systems (median coefficient of variation of the five loads: T-Force: MV = 4.25%, MPV = 4.49% and Vmax = 3.45%; Velowin: MV = 4.29%, MPV = 4.60% and Vmax = 4.44%), (2) the Vmax was the most reliable variable when obtained by the T-force (p < 0.05), but no significant differences in the reliability of the variables were observed for the Velowin (p > 0.05), and (3) high correlations were observed for the values of MV (r = 0.976), MPV (r = 0.965) and Vmax (r = 0.977) between the T-Force and Velowin systems. Collectively, these results support the Velowin as a reliable and valid system for the measurement of movement velocity during the free-weight back squat exercise.
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Purpose: This investigation examined the validity of two kinematic systems for assessing mean velocity (MV), peak velocity (PV), mean force (MF), peak force (PF), mean power (MP), and peak power (PP) during the full depth free-weight back squat performed with maximal concentric effort. Methods: Ten strength-trained men (26.1±3.0 y; 1.81±0.07 m; 82.0±10.6 kg) performed three 1-repetition maximum (1RM) trials on three separate days, encompassing lifts performed at six relative intensities including 20, 40, 60, 80, 90, and 100% of 1RM. Each repetition was simultaneously recorded by a PUSH band, commercial linear position transducer (LPT) (GymAware [GYM]), and compared with measurements collected by a laboratory based testing device consisting of four LPTs and a force plate. Results: Trials 2 and 3 were used for validity analyses, combining all 120 repetitions indicated the GYM was highly valid for assessing all criterion variables while the PUSH(TM) was only highly valid for estimations of PF (r=0.94; CV=5.4%; ES=0.28; SEE=135.5 N). At each relative intensity, the GYM was highly valid for assessing all criterion variables except for PP at 20% (ES=0.81) and 40% (ES=0.67) of 1RM. Moreover, the PUSH(TM) was only able to accurately estimate PF across all relative intensities (r=0.92-0.98; CV=4.0-8.3%; ES=0.04-0.26; SEE=79.8-213.1 N). Conclusions: The PUSH accuracy for determining MV, PV, MF, MP, and PP across all six relative intensities was questionable for the back squat, yet the GYM was highly valid at assessing all criterion variables, with some caution given to estimations of MP and PP performed at lighter loads.
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The purpose of this study was to analyse the validity and reliability of a novel iPhone app (named: PowerLift) for the measurement of mean velocity on the bench-press exercise. Additionally, the accuracy of the estimation of the 1-Repetition maximum (1RM) using the load–velocity relationship was tested. To do this, 10 powerlifters (Mean (SD): age = 26.5 ± 6.5 years; bench press 1RM · kg−1 = 1.34 ± 0.25) completed an incremental test on the bench-press exercise with 5 different loads (75–100% 1RM), while the mean velocity of the barbell was registered using a linear transducer (LT) and Powerlift. Results showed a very high correlation between the LT and the app (r = 0.94, SEE = 0.028 m · s−1) for the measurement of mean velocity. Bland–Altman plots (R2 = 0.011) and intraclass correlation coefficient (ICC = 0.965) revealed a very high agreement between both devices. A systematic bias by which the app registered slightly higher values than the LT (P < 0.05; mean difference (SD) between instruments = 0.008 ± 0.03 m · s−1). Finally, actual and estimated 1RM using the app were highly correlated (r = 0.98, mean difference (SD) = 5.5 ± 9.6 kg, P < 0.05). The app was found to be highly valid and reliable in comparison with a LT. These findings could have valuable practical applications for strength and conditioning coaches who wish to measure barbell velocity in the bench-press exercise.
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This study analysed the validity and reliability of a new optoelectronic device (Velowin) for the measurement of vertical displacement and velocity as well as to estimate force and mechanical power. Eleven trained males with Mean (SD) age = 27.4 (4.8) years, completed an incremental squat exercise test with 5 different loads (<30–90% of their 1−repetition maximum) while displacement and vertical velocity of the barbell were simultaneously measured using an integrated 3D system (3D motion capture system + force platform) and Velowin. Substantial to almost perfect correlation (concordance correlation coefficient = 0.75–0.96), root mean square error as coefficient of variation ±90% confidence interval ≤10% and good to excellent intraclass correlation coefficient = 0.84–0.99 were determined for all the variables. Passing and Bablock regression methods revealed no differences for average velocity. However, significant but consistent bias were determined for average or peak force and power while systematic and not proportional bias was found for displacement. In conclusion, Velowin, in holds of some potential advantages over traditionally used accelerometer or linear transducers, represents a valid and reliable alternative to monitor vertical displacement and velocity as well as to estimate average force and mechanical power during the squat exercise.
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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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