Validity and Effects of Placement of Velocity-Based Training Devices

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.

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Number of Repetitions Performed Before and After Reaching Velocity Loss Thresholds: First Repetition Versus Fastest Repetition—Mean Velocity Versus Peak Velocity

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2020-0629 ◽

2020 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Amador García-Ramos ◽

Jonathon Weakley ◽

Danica Janicijevic ◽

Ivan Jukic

Keyword(s):

Resistance Training ◽

Bench Press ◽

Peak Velocity ◽

Velocity Versus ◽

Mean Velocity ◽

Repetition Maximum ◽

Before And After ◽

Versus Peak ◽

First Time

Purpose: To explore the effect of several methodological factors on the number of repetitions performed before and after reaching certain velocity loss thresholds (VLTs). Method: Fifteen resistance-trained men (bench press 1-repetition maximum = 1.25 [0.16] kg·kg−1) performed with maximum intent a total of 182 sets (77 short sets [≤12 repetitions] and 105 long sets [>12 repetitions]) leading to failure during the Smith machine bench press exercise. Fifteen percent, 30%, and 45% VLTs were calculated, considering 2 reference repetitions (first and fastest repetitions) and 2 velocity variables (mean velocity [MV] and peak velocity [PV]). Results: The number of repetitions performed before reaching all VLTs were affected by the reference repetition and velocity variable (P ≤ .001). The fastest MV and PV during the short sets (75.3%) and PV during the long sets (72.4%) were predominantly observed during the first repetition, while the fastest MV during long sets was almost equally distributed between the first (37.1%) and second repetition (40.0%). Failure occurred before reaching the VLTs more frequently using PV (4, 8, and 33 occasions for 15%, 30%, and 45% VLTs, respectively) than MV (only 1 occasion for the 45% VLT). The participants rarely produced a velocity output above a VLT once this threshold was exceeded for the first time (≈10% and 30% of occasions during the short and long sets, respectively). Conclusions: The reference repetition and velocity variable are important factors to consider when implementing VLTs during resistance training. The fastest repetition (instead of the first repetition) and MV (instead of PV) are recommended.

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High-velocity Resistance Training Improves Strength In Individuals With Parkinson’s Disease

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000493704.71556.fe ◽

2014 ◽

Vol 46 ◽

pp. 175

Author(s):

Bruno Fischer ◽

Ricardo Oliveira ◽

Tácio Santos ◽

Tailce Leite ◽

Samuel Vidal ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Resistance Training ◽

High Velocity

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Left atrial 4D flow cardiovascular magnetic resonance: a reproducibility study in sinus rhythm and atrial fibrillation

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/s12968-021-00729-0 ◽

2021 ◽

Vol 23 (1) ◽

Author(s):

Marco Spartera ◽

Guilherme Pessoa-Amorim ◽

Antonio Stracquadanio ◽

Adam Von Ende ◽

Alison Fletcher ◽

...

Keyword(s):

Atrial Fibrillation ◽

Blood Pressure ◽

Heart Rate ◽

Cardiovascular Magnetic Resonance ◽

Magnetic Resonance ◽

Sinus Rhythm ◽

Left Atrial ◽

Peak Velocity ◽

4D Flow ◽

Mean Velocity

Abstract Background Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) allows sophisticated quantification of left atrial (LA) blood flow, and could yield novel biomarkers of propensity for intra-cardiac thrombus formation and embolic stroke. As reproducibility is critically important to diagnostic performance, we systematically investigated technical and temporal variation of LA 4D flow in atrial fibrillation (AF) and sinus rhythm (SR). Methods Eighty-six subjects (SR, n = 64; AF, n = 22) with wide-ranging stroke risk (CHA2DS2VASc 0–6) underwent LA 4D flow assessment of peak and mean velocity, vorticity, vortex volume, and stasis. Eighty-five (99%) underwent a second acquisition within the same session, and 74 (86%) also returned at 30 (27–35) days for an interval scan. We assessed variability attributable to manual contouring (intra- and inter-observer), and subject repositioning and reacquisition of data, both within the same session (same-day scan–rescan), and over time (interval scan). Within-subject coefficients of variation (CV) and bootstrapped 95% CIs were calculated and compared. Results Same-day scan–rescan CVs were 6% for peak velocity, 5% for mean velocity, 7% for vorticity, 9% for vortex volume, and 10% for stasis, and were similar between SR and AF subjects (all p > 0.05). Interval-scan variability was similar to same-day scan–rescan variability for peak velocity, vorticity, and vortex volume (all p > 0.05), and higher for stasis and mean velocity (interval scan CVs of 14% and 8%, respectively, both p < 0.05). Longitudinal changes in heart rate and blood pressure at the interval scan in the same subjects were associated with significantly higher variability for LA stasis (p = 0.024), but not for the remaining flow parameters (all p > 0.05). SR subjects showed significantly greater interval-scan variability than AF patients for mean velocity, vortex volume, and stasis (all p < 0.05), but not peak velocity or vorticity (both p > 0.05). Conclusions LA peak velocity and vorticity are the most reproducible and temporally stable novel LA 4D flow biomarkers, and are robust to changes in heart rate, blood pressure, and differences in heart rhythm.

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A Combined CFD/MRV Study of Flow Through a Pin Bank

Volume 5A: Heat Transfer ◽

10.1115/gt2014-25350 ◽

2014 ◽

Cited By ~ 3

Author(s):

Mike Siekman ◽

David Helmer ◽

Wontae Hwang ◽

Gregory Laskowski ◽

Ek Tsoon Tan ◽

...

Keyword(s):

Magnetic Resonance ◽

Velocity Field ◽

Turbulence Model ◽

Field Data ◽

Peak Velocity ◽

Velocity Profiles ◽

Mean Velocity ◽

Magnetic Resonance Velocimetry ◽

Sst Turbulence Model ◽

Flow Through

RANS and time averaged URANS simulations of a pin bank are compared quantitatively and qualitatively to full 3D mean velocity field data obtained using magnetic resonance velocimetry (MRV). The ability of the CFD to match MRV velocity profiles through the pin bank is evaluated using the SST turbulence model. Quantitative comparisons of the velocity profiles showed an overprediction of peak velocity by the CFD at the first pin rows, and a smaller oscillatory error that diminishes as it moves through the pins, resulting in better matching towards the exit.

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Effect of Individualized High-Velocity Resistance Training on Balance Performance in Children with Cerebral Palsy

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000477269.20344.8a ◽

2015 ◽

Vol 47 ◽

pp. 310

Author(s):

Moataz Eltoukhy ◽

Gabriela Wagener ◽

Andrew Ordille ◽

Kelly Drozdowicz ◽

Casey Epstein ◽

...

Keyword(s):

Cerebral Palsy ◽

Resistance Training ◽

High Velocity ◽

Balance Performance ◽

Children With Cerebral Palsy

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Correction: Effects of high-velocity resistance training and creatine supplementation in untrained healthy aging males

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0575 ◽

2020 ◽

Vol 45 (8) ◽

pp. 916-916

Author(s):

Patrick Bernat ◽

Darren G. Candow ◽

Karolina Gryzb ◽

Sara Butchart ◽

Brad J. Schoenfeld ◽

...

Keyword(s):

Resistance Training ◽

High Velocity ◽

Healthy Aging ◽

Creatine Supplementation

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Validity and Reliability of Kinematics Measured with PUSH Band vs. Linear Encoder in Bench Press and Push-Ups

Sports ◽

10.3390/sports7090207 ◽

2019 ◽

Vol 7 (9) ◽

pp. 207 ◽

Cited By ~ 4

Author(s):

Roland van den Tillaar ◽

Nick Ball

Keyword(s):

Bench Press ◽

Peak Velocity ◽

Validity And Reliability ◽

Mean Velocity ◽

Movement Velocity ◽

Lower Velocity ◽

Linear Encoder ◽

Measurement Devices ◽

Level Of Agreement ◽

Push Up

Background: The aim of this study was to compare the validity and reliability of a PUSH band device with a linear encoder to measure movement velocity with different loads during the push-up and bench press exercises. Methods: Twenty resistance-trained athletes performed push-up and bench press exercises with four different loads: without weight vest, 10-20-30 kg weight vest, bench press: 50–82% of their assumed 1 repetition maximum (1 RM) in steps of 10 kg. A linear encoder (Musclelab) and the PUSH band measured mean and peak velocity during both exercises. Several statistical analyses were used to investigate the validity and reliability of the PUSH band with the linear encoder. Results: The main findings of this study demonstrated only moderate associations between the PUSH band and linear encoder for mean velocity (r = 0.62, 0.70) and peak velocity (r = 0.46, 0.49) for both exercises. Furthermore, a good level of agreement (peak velocity: ICC = 0.60, 0.64; mean velocity: ICC = 0.77, 0.78) was observed between the two measurement devices. However, a significant bias was found with lower velocity values measured with the PUSH band in both exercises. In the push-up, both the linear encoder and PUSH band were deemed very reliable (ICC > 0.98; the coefficient of variation (CV): 5.9–7.3%). Bench press reliability decreased for the PUSH band (ICC < 0.95), and the coefficient of variance increased to (12.8–13.3%) for the velocity measures. Calculated 1 RM with the two devices was the same for the push-up, while in bench press the PUSH band under-estimated the 1 RM by 14 kg compared to the linear encoder. Conclusions: It was concluded that the PUSH band will show decreased reliability from velocity measures in a bench press exercise and underestimate load-velocity based 1 RM predictions. For training, the PUSH band can be used during push-ups, however caution is suggested when using the device for the purposes of feedback in bench press at increasing loads.

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Validation of Inertial Sensor to Measure Barbell Kinematics across a Spectrum of Loading Conditions

Sports ◽

10.3390/sports8070093 ◽

2020 ◽

Vol 8 (7) ◽

pp. 93

Author(s):

John C. Abbott ◽

John P. Wagle ◽

Kimitake Sato ◽

Keith Painter ◽

Thaddeus J. Light ◽

...

Keyword(s):

Effect Size ◽

Peak Velocity ◽

Inertial Sensor ◽

Measurement Unit ◽

Mean Velocity ◽

Back Squat ◽

Pearson Correlations ◽

Internal Error ◽

3D Motion Capture ◽

Level Of Agreement

The aim of this study was to evaluate the level of agreement in measuring back squat kinematics between an inertial measurement unit (IMU) and a 3D motion capture system (3DMOCAP). Kinematic variables included concentric peak velocity (CPV), concentric mean velocity (CMV), eccentric peak velocity (EPV), eccentric mean velocity (EMV), mean propulsive velocity (MPV), and POP-100: a proprietary variable. Sixteen resistance-trained males performed an incrementally loaded one repetition maximum (1RM) squat protocol. A series of Pearson correlations, 2 × 4 RM ANOVA, Cohen’s d effect size differences, coefficient of variation (CV), and standard error of the estimate (SEE) were calculated. A large relationship existed for all variables between devices (r = 0.78–0.95). Between-device agreement for CPV worsened beyond 60% 1RM. The remaining variables were in agreement between devices with trivial effect size differences and similar CV magnitudes. These results support the use of the IMU, regardless of relative intensity, when measuring EMV, EPV, MPV, and POP-100. However, practitioners should carefully select kinematic variables of interest when using the present IMU device for velocity-based training (VBT), as certain measurements (e.g., CMV, CPV) do not possess practically acceptable reliability or accuracy. Finally, the IMU device exhibited considerable practical data collection concerns, as one participant was completely excluded and 13% of the remaining attempts displayed obvious internal error.

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The Reliability and Validity of Current Technologies for Measuring Barbell Velocity in the Free-Weight Back Squat and Power Clean

Sports ◽

10.3390/sports8070094 ◽

2020 ◽

Vol 8 (7) ◽

pp. 94

Author(s):

Steve W. Thompson ◽

David Rogerson ◽

Harry F. Dorrell ◽

Alan Ruddock ◽

Andrew Barnes

Keyword(s):

Peak Velocity ◽

Reliability And Validity ◽

Systematic Bias ◽

Mean Velocity ◽

Validity Data ◽

Back Squat ◽

Free Weight ◽

Device Reliability ◽

Measurement Units ◽

Power Clean

This study investigated the inter-day and intra-device reliability, and criterion validity of six devices for measuring barbell velocity in the free-weight back squat and power clean. In total, 10 competitive weightlifters completed an initial one repetition maximum (1RM) assessment followed by three load-velocity profiles (40–100% 1RM) in both exercises on four separate occasions. Mean and peak velocity was measured simultaneously on each device and compared to 3D motion capture for all repetitions. Reliability was assessed via coefficient of variation (CV) and typical error (TE). Least products regression (LPR) (R2) and limits of agreement (LOA) assessed the validity of the devices. The Gymaware was the most reliable for both exercises (CV < 10%; TE < 0.11 m·s−1, except 100% 1RM (mean velocity) and 90‒100% 1RM (peak velocity)), with MyLift and PUSH following a similar trend. Poorer reliability was observed for Beast Sensor and Bar Sensei (CV = 5.1–119.9%; TE = 0.08–0.48 m·s−1). The Gymaware was the most valid device, with small systematic bias and no proportional or fixed bias evident across both exercises (R2 > 0.42–0.99 LOA = −0.03–0.03 m·s−1). Comparable validity data was observed for MyLift in the back squat. Both PUSH devices produced some fixed and proportional bias, with Beast Sensor and Bar Sensei being the least valid devices across both exercises (R2 > 0.00–0.96, LOA = −0.36–0.46 m·s−1). Linear position transducers and smartphone applications could be used to obtain velocity-based data, with inertial measurement units demonstrating poorer reliability and validity.

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