Perception of bar velocity in resistance training: Accuracy levels within and between exercises

Velocity-based training is a method used to monitor resistance-training programs based on repetition velocities measured with tracking devices. Since velocity measuring devices can be expensive and impractical, trainee’s perception of velocity (POV) may be used as a possible substitute. Here, 20 resistance-trained males first completed 1RM tests in the bench-press and squat. Then, in three counterbalanced sessions, participants completed four sets of eight repetitions in both exercises using 60%1RM (two-sessions) or 70%1RM. Starting from the second repetition, participants reported their POV of each repetition as a percentage of the first repetition. Accuracy was calculated as the difference between POV and actual-velocity measured with a linear-encoder. Two key findings emerged. First, the absolute error in both exercises was ~5.8 percentage-points in the second repetition, and it increased to 13.2 and 16.7 percentage-points by the eighth repetition, in the bench-press and squat, respectively. Second, participants were 4.2 times more likely to underestimate velocity in the squat. Given the gradual increments in the absolute error, POV may be better suited for sets of fewer repetitions (e.g., 4-5) and wider velocity-loss threshold ranges (e.g., 5-10%). Given the systematic underestimation error in the squat, a correction factor may increase POV accuracy in this exercise.

Download Full-text

Prediction of One Repetition Maximum Using Reference Minimum Velocity Threshold Values in Young and Middle-Aged Resistance-Trained Males

Behavioral Sciences ◽

10.3390/bs11050071 ◽

2021 ◽

Vol 11 (5) ◽

pp. 71

Author(s):

John F. T. Fernandes ◽

Amelia F. Dingley ◽

Amador Garcia-Ramos ◽

Alejandro Perez-Castilla ◽

James J. Tufano ◽

...

Keyword(s):

Bench Press ◽

Absolute Error ◽

Young Group ◽

Middle Aged ◽

Repetition Maximum ◽

Back Squat ◽

Velocity Threshold ◽

Low Load ◽

The Absolute ◽

Minimum Velocity

Background: This study determined the accuracy of different velocity-based methods when predicting one-repetition maximum (1RM) in young and middle-aged resistance-trained males. Methods: Two days after maximal strength testing, 20 young (age 21.0 ± 1.6 years) and 20 middle-aged (age 42.6 ± 6.7 years) resistance-trained males completed three repetitions of bench press, back squat, and bent-over-row at loads corresponding to 20–80% 1RM. Using reference minimum velocity threshold (MVT) values, the 1RM was estimated from the load-velocity relationships through multiple (20, 30, 40, 50, 60, 70, and 80% 1RM), two-point (20 and 80% 1RM), high-load (60 and 80% 1RM) and low-load (20 and 40% 1RM) methods for each group. Results: Despite most prediction methods demonstrating acceptable correlations (r = 0.55 to 0.96), the absolute errors for young and middle-aged groups were generally moderate to high for bench press (absolute errors = 8.2 to 14.2% and 8.6 to 20.4%, respectively) and bent-over-row (absolute error = 14.9 to 19.9% and 8.6 to 18.2%, respectively). For squats, the absolute errors were lower in the young group (5.7 to 13.4%) than the middle-aged group (13.2 to 17.0%) but still unacceptable. Conclusion: These findings suggest that reference MVTs cannot accurately predict the 1RM in these populations. Therefore, practitioners need to directly assess 1RM.

Download Full-text

Intraocular Lens Power Calculation According to the Difference between Anterior and Total Keratometry Using Scheimpflug Imaging

Journal of the Korean Ophthalmological Society ◽

10.3341/jkos.2021.62.9.1181 ◽

2021 ◽

Vol 62 (9) ◽

pp. 1181-1188

Author(s):

Joong Hee Kim ◽

Kyong Jin Cho ◽

Ho Seok Chung

Keyword(s):

Regression Analysis ◽

Absolute Error ◽

Power Calculation ◽

Intraocular Lens Power Calculation ◽

Refractive Power ◽

Simple Regression Analysis ◽

The Absolute ◽

The Difference ◽

Lens Power ◽

Simple Regression

Purpose: We investigated the change in the absolute error according to the difference between anterior and total keratometry, to determine the criterion for the difference in keratometry, and to determine the indication for using total keratometry. Methods: Sagittal and total refractive power were measured with 2-, 3-, and 4-mm Pentacam® rings, and the absolute error of each was calculated in patients who underwent cataract surgery in our hospital. The correlation between the difference value the sagittal minus the total refractive power and each absolute error was analyzed by simple regression analysis. The analysis was performed by dividing the patients into two groups based on 0.6, which is the average of the difference between the sagittal and total refractive power for the 3-mm ring. Results: Sagittal power was larger than total refractive power for all rings and the absolute error obtained by applying the total refractive power was larger than the sagittal power for the 2- and 4-mm rings (p < 0.001). The simple regression analysis revealed that the absolute error using sagittal power was positively correlated with the difference between sagittal power and total refractive power. In the group with less than 0.6, the absolute error using the total refractive power of all rings was larger than the sagittal power (p < 0.001). In the group exceeding 0.6, the absolute error using the total refractive power was less than using the sagittal power for the 3 mm ring (p = 0.028). Conclusions: The greater the difference between sagittal and total refractive power, the greater the absolute error using sagittal power. Accuracy was higher in the group exceeding 0.6 after applying total refractive power measured at the 3 mm ring compared to sagittal power.

Download Full-text

How one feels during resistance exercises: A repetition by repetition analysis across exercises and loads

10.31236/osf.io/4qbgj ◽

2019 ◽

Author(s):

Aviv Emanuel ◽

Itzhak Rozen Smukas ◽

Israel Halperin

Keyword(s):

Resistance Training ◽

Bench Press ◽

Affective Valence ◽

Trained Subjects ◽

Task Failure ◽

Position Transducer ◽

Feeling Scale ◽

Resistance Exercises ◽

Bar Velocity

Purpose: The feeling scale (FS) is a unique and underexplored scale in sport sciences that measures affective valence. FS has the potential to be used in athletic environments as a monitoring and prescription tool. We sought to examine whether FS ratings, as measured on a repetition-by-repetition basis, can predict proximity to task-failure and bar velocity across different exercises and loads. Methods: On the first day, 20 trained subjects (10 females) completed 1RM tests in the barbell bench and squat exercises and were introduced to the FS. On the following three sessions, subjects completed three sets to task-failure with either 1) 70%1RM bench-press, 2) 70%1RM squat (squat-70%), or 3) 80%1RM squat (squat-80%). Sessions were completed in a randomized, counter-balanced order. After every completed repetition, subjects verbally reported their FS ratings. Bar velocity was measured via linear position transducer. Results: FS ratings predicted failure-proximity and bar velocity in all three conditions (p<0.001, R2 range: 0.66-0.85). Specifically, a reduction of one unit in the FS corresponded to approaching task-failure by 14%, 11% and 11%, and to a reduction in bar velocity of 10%, 4% and 3%, in the bench, squat-70% and squat-80%, respectively. Conclusion: This is the first study to investigate if the FS can be used in RT environments among trained subjects, on a repetition-by-repetition basis. The results show strong predictive abilities of the FS, indicating that the scale can be used to monitor and prescribe resistance training, and that its benefits should be further explored.

Download Full-text

Acute Effects of Continuous and Intermittent Blood Flow Restriction on Movement Velocity During Bench Press Exercise Against Different Loads

Frontiers in Physiology ◽

10.3389/fphys.2020.569915 ◽

2020 ◽

Vol 11 ◽

Author(s):

Michal Wilk ◽

Mariola Gepfert ◽

Michal Krzysztofik ◽

Petr Stastny ◽

Adam Zajac ◽

...

Keyword(s):

Blood Flow ◽

Resistance Training ◽

Bench Press ◽

Arterial Occlusion ◽

Blood Flow Restriction ◽

Experimental Session ◽

Training Experience ◽

Flow Restriction ◽

Wide Range ◽

Bar Velocity

This study evaluated the effects of continuous and intermittent blood flow restriction (BFR) with 70% of full arterial occlusion pressure on bar velocity during the bench press exercise against a wide range of resistive loads. Eleven strength-trained males (age: 23.5 ± 1.4 years; resistance training experience: 2.8 ± 0.8 years, maximal bench press strength – 1RM = 101.8 ± 13.9 kg; body mass = 79.8 ± 10.4 kg), performed three different testing protocols in random and counterbalanced order: without BFR (NO-BFR); intermittent BFR (I-BFR) and continuous BFR (C-BFR). During each experimental session, subjects performed eight sets of two repetitions each, with increasing loads from 20 to 90% 1RM (10% steps), and 3 min rest between each set. In the C-BFR condition occlusion was kept throughout the trial, while in the I-BFR, occlusion was released during each 3 min rest interval. Peak bar velocity (PV) during the bench press exercise was higher by 12–17% in both I-BFR and C-BFR compared with NO-BFR only at the loads of 20, 30, 40, and 50% 1RM (p < 0.001), while performance at higher loads remained unchanged. Mean bar velocity (MV) was unaffected by occlusion (p = 0.342). These results indicate that BFR during bench press exercise increases PV and this may be used as an enhanced stimulus during explosive resistance training. At higher workloads, bench press performance was not negatively affected by BFR, indicating that the benefits of exercise under occlusion can be obtained while explosive performance is not impaired.

Download Full-text

Performance Evaluation of Regression Analysis Algorithms in Predicting the Enrollment of Basic Education

International Journal of Emerging Technology and Advanced Engineering ◽

10.46338/ijetae0122_17 ◽

2022 ◽

Vol 12 (1) ◽

pp. 173-177

Author(s):

Elizalde L. Piol ◽

◽

Luisito Lolong Lacatan ◽

Jaime P. Pulumbarit

Keyword(s):

Regression Analysis ◽

Performance Evaluation ◽

Linear Regression ◽

Basic Education ◽

Absolute Error ◽

The Philippines ◽

Fundamental Parameters ◽

Percentage Points ◽

Data Collecting ◽

The Absolute

The use of Linear Regression in predicting enrolment has been shown to be beneficial, although it varies with various datasets and attributes; varying weights of the correlation of the attributes can be discarded if they do not impact the prediction. Data collecting had grown since prior investigations, resulting in a more complicated dataset with many varieties. As a result of the data being created by multiple clerks, cleaning and combining proved tough; nonetheless, the fundamental parameters remain intact. Different algorithms were examined but Linear Regression obtained the highest accuracy with a 12.398 percentage for the absolute error and a root mean squared of 26.936 to create a tangible model to anticipate the enrolment of Region IVA CALABARZON in the Philippines. This demonstrates that it was 2.067 percentage points more than the prior research.

Download Full-text

How One Feels During Resistance Exercises: A Repetition-by-Repetition Analysis Across Exercises and Loads

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2019-0733 ◽

2021 ◽

Vol 16 (1) ◽

pp. 135-144 ◽

Cited By ~ 1

Author(s):

Aviv Emanuel ◽

Isaac Rozen Smukas ◽

Israel Halperin

Keyword(s):

Resistance Training ◽

Bench Press ◽

Affective Valence ◽

Repetition Maximum ◽

Task Failure ◽

Position Transducer ◽

Feeling Scale ◽

Resistance Exercises ◽

Bar Velocity

Context: The Feeling Scale (FS) is a unique and underexplored scale in sport sciences that measures affective valence. The FS has the potential to be used in athletic environments as a monitoring and prescription tool. Purpose: To examine whether FS ratings, as measured on a repetition-by-repetition basis, can predict proximity to task failure and bar velocity across different exercises and loads. Methods: On the first day, 20 trained participants (10 females) completed 1-repetition-maximum (1-RM) tests in the barbell bench and squat exercises and were introduced to the FS. In the following 3 sessions, participants completed 3 sets to task failure with either (1) 70% 1-RM bench press, (2) 70% 1-RM squat (squat-70%), or (3) 80% 1-RM squat (squat-80%). Sessions were completed in a randomized, counterbalanced order. After every completed repetition, participants verbally reported their FS ratings. Bar velocity was measured via a linear position transducer. Results: FS ratings predicted failure proximity and bar velocity in all 3 conditions (P < .001, R2 .66–.85). Based on the analysis, which included over 2400 repetitions, a reduction of 1 unit in the FS corresponded to approaching task failure by 14%, 11%, and 11%, and to a reduction in bar velocity of 10%, 4%, and 3%, in the bench, squat-70%, and squat-80%, respectively. Conclusion: This is the first study to investigate whether the FS can be used in resistance-training environments among resistance-trained participants on a repetition-by-repetition basis. The results indicate that the FS can be used to monitor and prescribe resistance training and that its benefits should be further explored.

Download Full-text

Can Post-Activation Performance Enhancement (PAPE) Improve Resistance Training Volume during the Bench Press Exercise?

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17072554 ◽

2020 ◽

Vol 17 (7) ◽

pp. 2554 ◽

Cited By ~ 3

Author(s):

Michal Krzysztofik ◽

Michal Wilk ◽

Aleksandra Filip ◽

Piotr Zmijewski ◽

Adam Zajac ◽

...

Keyword(s):

Resistance Training ◽

Power Output ◽

Repeated Measures ◽

Peak Power ◽

Bench Press ◽

Performance Enhancement ◽

Peak Power Output ◽

Training Volume ◽

Training Experience ◽

Bar Velocity

Background: The aim of the present study was to evaluate the effects of post-activation performance enhancement (PAPE) on resistance training volume during the bench press exercise (BP). The study included 12 healthy strength-trained males (age 25.2 ± 2.1 years, body mass 92.1 ± 8.7 kg, BP one-repetition maximum (1RM) 28.8 ± 10.5 kg, training experience 6.3 ± 2.1 years). Methods: The experiment was performed following a randomized crossover design, where each participant performed two different exercise protocols with a conditioning activity (CA) consisting of the BP with three sets of three repetitions at 85% 1RM (PAPE), and a control without the CA (CONT). To assess the differences between PAPE and CONT, the participants performed three sets of the BP to volitional failure at 60% 1RM. The differences in the number of performed repetitions (REP), time under tension (TUT), peak power output (PP), mean of peak power output (PPMEAN), mean power output (MP), peak bar velocity (PV), mean of peak bar velocity (PVMEAN), and mean bar velocity (MV) between the CONT and PAPE conditions were examined using repeated measures ANOVA. Results: The post-hoc analysis for the main condition effect indicated significant increases in TUT (p < 0.01) for the BP following PAPE, compared to the CONT condition. Furthermore, there was a significant increase in TUT (p < 0.01) in the third set for PAPE compared to the CONT condition. No statistically significant main effect was revealed for REP, PP, PV, PPMEAN, PVMEAN, MP, and MV. Conclusion: The main finding of the study was that the PAPE protocol increased training volume based on TUT, without changes in the number of preformed REP.

Download Full-text

Perception of changes in bar velocity as a resistance training monitoring tool for trained athletes

10.31236/osf.io/qstkp ◽

2020 ◽

Author(s):

Amit Lazarus ◽

Israel Halperin ◽

Gal Yosef Vaknin ◽

Antonio Dello Iacono

Keyword(s):

Resistance Training ◽

Absolute Difference ◽

Average Error ◽

Monitoring Tool ◽

Post Intervention ◽

Optimal Power ◽

Power Load ◽

Bar Velocity ◽

Tracking Devices ◽

Velocity Tracking

Purpose: To investigate if perception of changes in bar velocity (PCV) can be used as a substitute for velocity tracking devices commonly used to monitor resistance-exercises. Methods: Twenty-one professional male soccer athletes (21.1±4.3 years) first went through a load-power profile assessment to determine their optimal power load in the back-squat. In the next three experimental sessions, athletes completed four sets of six repetitions loaded with optimal power load. Starting from the second repetition, athletes reported their PCV of each repetition as a percentage of the first repetition. Accuracy of PCV was calculated as the absolute difference between PCV and the actual percentage change from the first repetition in bar velocity measured with a linear-encoder. The second and fourth sessions served as the pre- and post-intervention sessions, in which athletes received no feedback about their PCV accuracy. The third session served as the intervention, in which athletes received verbal and visual feedback about their PCV accuracy levels after each set. Results: The estimated accuracy of PCV decreased from an average error of 7% in the pre-intervention to an average error of 4.7% in the post-intervention session (95% confidence levels of difference: 1.5, 3.0). Conclusion: Athletes with velocity based training experience begin with a reasonable PCV accuracy rates which can be meaningfully improved after a single feedback session. When velocity tracking devices are impractical or absent, PCV can be implemented as a resistance training monitoring tool.

Download Full-text

Translocation Relative to Range

Methodology ◽

10.1027/1614-2241.4.3.132 ◽

2008 ◽

Vol 4 (3) ◽

pp. 132-138 ◽

Cited By ~ 3

Author(s):

Michael Höfler

Keyword(s):

Risk Difference ◽

Binary Outcomes ◽

Number Needed To Treat ◽

Likert Scales ◽

Psychological Science ◽

The Absolute ◽

The Difference ◽

Variance Parameters ◽

Standardized Index ◽

Maximum Possible Magnitude

A standardized index for effect intensity, the translocation relative to range (TRR), is discussed. TRR is defined as the difference between the expectations of an outcome under two conditions (the absolute increment) divided by the maximum possible amount for that difference. TRR measures the shift caused by a factor relative to the maximum possible magnitude of that shift. For binary outcomes, TRR simply equals the risk difference, also known as the inverse number needed to treat. TRR ranges from –1 to 1 but is – unlike a correlation coefficient – a measure for effect intensity, because it does not rely on variance parameters in a certain population as do effect size measures (e.g., correlations, Cohens d). However, the use of TRR is restricted on outcomes with fixed and meaningful endpoints given, for instance, for meaningful psychological questionnaires or Likert scales. The use of TRR vs. Cohens d is illustrated with three examples from Psychological Science 2006 (issues 5 through 8). It is argued that, whenever TRR applies, it should complement Cohens d to avoid the problems related to the latter. In any case, the absolute increment should complement d.

Download Full-text