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

2021 ◽  
Vol 231 ◽  
pp. 113316
Author(s):  
Amit Lazarus ◽  
Israel Halperin ◽  
Gal Josef Vaknin ◽  
Antonio Dello Iacono
2020 ◽  
Author(s):  
Amit Lazarus ◽  
Israel Halperin ◽  
Gal Yosef Vaknin ◽  
Antonio Dello Iacono

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.


2020 ◽  
Vol 224 ◽  
pp. 113025
Author(s):  
Mahmood Sindiani ◽  
Amit Lazarus ◽  
Antonio Dello Iacono ◽  
Israel Halperin

2019 ◽  
Author(s):  
Aviv Emanuel ◽  
Itzhak Rozen Smukas ◽  
Israel Halperin

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.


2019 ◽  
Vol 47 (7) ◽  
pp. 1523-1538 ◽  
Author(s):  
Javier Courel-Ibáñez ◽  
Alejandro Martínez-Cava ◽  
Ricardo Morán-Navarro ◽  
Pablo Escribano-Peñas ◽  
Javier Chavarren-Cabrero ◽  
...  

2020 ◽  
Vol 11 ◽  
Author(s):  
Michal Wilk ◽  
Mariola Gepfert ◽  
Michal Krzysztofik ◽  
Petr Stastny ◽  
Adam Zajac ◽  
...  

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.


2021 ◽  
Author(s):  
Petrus Gantois ◽  
Fábio Yuzo Nakamura ◽  
Julian Alcazar ◽  
Leonardo de Sousa Fortes ◽  
Fernando Pareja-Blanco ◽  
...  

Abstract Background: The level of effort seems to play a key role in determining neuromuscular adaptations; however, less is known regarding the optimal dose-response for intra-set levels of effort on chronic resistance training (RT) adaptations. Objective: We aimed to synthesize the current literature on chronic RT adaptations in response to different intra-set velocity loss (VL) thresholds in the back squat exercise. We investigated changes in muscle strength, muscular endurance, sports-related physical performance, and muscle hypertrophy outcomes during resistance exercise to establish optimal dose-response relationships in physically active individuals.Methods: We conducted a literature search using PubMed (Medline), Web of Science™, Scopus, and Cochrane up to April 2021, with no restriction on year of publication. The inclusion criteria were based on the PICO strategy. A random-effect meta-analysis was performed to determine the standardized mean differences (SMD ± 95% confidence intervals) for different intra-set VL thresholds (low VL [< 15%], moderate VL [≥ 15% and < 30%], and high VL [≥ 30%]) in RT on maximum muscular strength, bar velocity against submaximal loads, endurance against a given load, countermovement jump height, running sprint time, and muscle hypertrophy. Results: A total of 4,031 articles were found and 11 studies met our eligibility criteria. Pooled results revealed improvements between pre- and post-training intervention in 1RM strength (SMD = 0.78; p < 0.001); bar velocity outputs (light-loads [SMD = 0.79; p < 0.001] and heavy-loads [SMD = 2.08; p < 0.001]); endurance against a given load (SMD = 1.21; p < 0.001); countermovement jump height (SMD = 0.50; p < 0.001); running sprint time (SMD = - 0.28; p = 0.001); and muscle hypertrophy (SMD = 0.31; p = 0.05), with no significant difference between VL thresholds (p > 0.05). However, low VL elicited greater within-group SMD for 1RM strength than moderate and high VL thresholds (SMD = 0.93; 0.72; and 0.75; for low, moderate, and high VL thresholds, respectively). Low and moderate VL thresholds resulted in greater within-group SMD than high VL thresholds for velocity against light loads (SMD for low VL = 0.89; moderate VL = 0.90; high VL = 0.59); countermovement jump height (SMD for low VL = 0.51; moderate VL = 0.58; high VL = 0.36); and running sprint time (SMD for low VL = -0.49; moderate VL = -0.32; high VL = -0.09). Moderate and high VL thresholds induced higher within-group SMD for muscle hypertrophy than low VL (SMD for low VL = 0.14; moderate VL = 0.40; high VL = 0.44). Conclusions: Low to moderate VL thresholds may provide more effective and efficient training stimuli for improving performance in strength-power tasks, due to the similar or even greater chronic adaptations achieved compared with high VL, despite the lower number of repetitions performed during the RT program. Conversely, moderate to high VL may provide more favorable training stimuli for inducing muscle hypertrophy. Strength coaches may apply these dose-response trends to design optimal RT stimuli based on their specific training goals. Protocol registration: The study protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020189321).


2021 ◽  
Vol 16 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Aviv Emanuel ◽  
Isaac Rozen Smukas ◽  
Israel Halperin

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.


Author(s):  
Michal Krzysztofik ◽  
Michal Wilk ◽  
Aleksandra Filip ◽  
Piotr Zmijewski ◽  
Adam Zajac ◽  
...  

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.


2020 ◽  
Author(s):  
Mahmood Sindiani ◽  
Amit Lazarus ◽  
Antonio Dello Iacono ◽  
Israel Halperin

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.


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