scholarly journals Influence of half-squat intensity and volume on the subsequent countermovement jump and frequency speed of kick test performance in taekwondo athletes

Kinesiology ◽  
2016 ◽  
Vol 48 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Jonatas Ferreira da Silva Santos ◽  
Tomás Herrera-Valenzuela ◽  
Gustavo Ribeiro da Mota ◽  
Emerson Franchini

The aim of this study was to assess the effects of different postactivation potentiation conditioning activities’ volumes and intensities on countermovement jump and multiple sets of high speed kicks. Nine taekwondo athletes (M±SD; age: 20.3±5.2 years; height: 177±7.2 cm; body mass: 71.8±15.3 kg; maximum dynamic half-squat 1RM: 132.8±32.5 kg and practice time: 9.6±7.2 years) participated. One control and four experimental conditions were randomly applied. Each condition was composed of warm-up, conditioning activity (half-squat: 1x3 at 50 or 90% 1RM or 3x3 at 50 or 90% 1RM), followed by a 10-minute rest interval, a countermovement jump and five sets of Frequency Speed of Kick Test. The conditions were compared using an analysis of variance with repeated measures, followed by Bonferroni post-hoc test. The alpha level was set at 5%. The significant difference was found in the number of kicks among sets (F3,21;128,36=25.34; p<.001; η2=.388 [small]). The rating of perceived exertion before control condition was higher than in all experimental protocols (F4,32=6.64; p=.001; η2=.454 [small]). There were no effects of volume and intensity on the variables investigated (maximum countermovement jump, mean countermovement jump, kick decrement, impact and rating of perceived exertion). Our results indicate that taekwondo athletes does not improve performance after conditioning activities of different volumes and intensities.

2020 ◽  
pp. 1-5
Author(s):  
Megan Wagner ◽  
Kevin D. Dames

Context: Bodyweight-supporting treadmills are popular rehabilitation tools for athletes recovering from impact-related injuries because they reduce ground reaction forces during running. However, the overall metabolic demand of a given running speed is also reduced, meaning athletes who return to competition after using such a device in rehabilitation may not be as fit as they had been prior to their injury. Objective: To explore the metabolic effects of adding incline during bodyweight-supported treadmill running. Design: Cross-sectional. Setting: Research laboratory. Participants: Fourteen apparently healthy, recreational runners (6 females and 8 males; 21 [3] y, 1.71 [0.08] m, 63.11 [6.86] kg). Interventions: The participants performed steady-state running trials on a bodyweight-supporting treadmill at 8.5 mph. The control condition was no incline and no bodyweight support. All experimental conditions were at 30% bodyweight support. The participants began the sequence of experimental conditions at 0% incline; this increased to 1%, and from there on, 2% incline increases were introduced until a 15% grade was reached. Repeated-measures analysis of variance was used to compare all bodyweight-support conditions against the control condition. Main Outcome Measures: Oxygen consumption, heart rate, and rating of perceived exertion. Results: Level running with 30% bodyweight support reduced oxygen consumption by 21.6% (P < .001) and heart rate by 12.0% (P < .001) compared with the control. Each 2% increase in incline with bodyweight support increased oxygen consumption by 6.4% and heart rate by 3.2% on average. A 7% incline elicited similar physiological measures as the unsupported, level condition. However, the perceived intensity of this incline with bodyweight support was greater than the unsupported condition (P < .001). Conclusions: Athletes can maintain training intensity while running on a bodyweight-supporting treadmill by introducing incline. Rehabilitation programs should rely on quantitative rather than qualitative data to drive exercise prescription in this modality.


Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3342
Author(s):  
Louise Jones ◽  
Iona Johnstone ◽  
Charlotte Day ◽  
Sasha Le Marquer ◽  
Andrew T. Hulton

Caffeine supplementation has shown to be an effective ergogenic aid enhancing athletic performance, although limited research within female populations exists. Therefore, the aim of the investigation was to assess the effect of pre-exercise caffeine supplementation on strength performance and muscular endurance in strength-trained females. In a double-blind, randomised, counterbalanced design, fourteen strength-trained females using hormonal contraception consumed either 3 or 6 mg·kg−1 BM of caffeine or placebo (PLA). Following supplementation, participants performed a one-repetition maximum (1RM) leg press and repetitions to failure (RF) at 60% of their 1RM. During the RF test, rating of perceived exertion (RPE) was recorded every five repetitions and total volume (TV) lifted was calculated. Repeated measures ANOVA revealed that RF (p = 0.010) and TV (p = 0.012) attained significance, with pairwise comparisons indicating a significant difference between 3 mg·kg−1 BM and placebo for RF (p = 0.014), with an effect size of 0.56, and for 6 mg·kg−1 BM (p = 0.036) compared to the placebo, with an effect size of 0.65. No further significance was observed for 1RM or for RPE, and no difference was observed between caffeine trials. Although no impact on lower body muscular strength was observed, doses of 3 and 6 mg·kg−1 BM of caffeine improved lower body muscular endurance in resistance-trained females, which may have a practical application for enhancing resistance training stimuli and improving competitive performance.


2016 ◽  
Vol 11 (2) ◽  
pp. 221-226 ◽  
Author(s):  
Leandro C. Felippe ◽  
João P. Lopes-Silva ◽  
Rômulo Bertuzzi ◽  
Cian McGinley ◽  
Adriano E. Lima-Silva

The combined supplementation of caffeine (CAF) and sodium bicarbonate (NaHCO3) may have a potential ergogenic effect during intermittent-exercise tasks such as judo; however, its effect in this sport has not been tested.Purpose:To investigate the isolated and combined effects of CAF and NaHCO3 on judo performance.Methods:Ten judokas performed 4 supplementation protocols—NaHCO3, CAF, NaHCO3 + CAF, and placebo (PLA) (cellulose)—followed by 3 Special Judo Fitness Tests (SJFTs) interspaced with 5 min rest.Results:In the first SJFT, the combined supplement (NaHCO3 + CAF) resulted in a higher number of throws than with PLA (24.4 ± 0.9 and 23.2 ± 1.5 throws, respectively, P = .02). There was no significant difference between conditions for the 2nd SJFT (P = .11). In the 3rd SJFT, NaHCO3 and NaHCO3 + CAF resulted in more throws than with PLA (23.7 ± 1.6, 24.4 ± 1.0, and 22.0 ± 1.6 throws, P = .001 and P = .03, respectively). When the total throws performed in the 3 SJFTs were summed, they were higher than PLA only for NaHCO3 + CAF (68.8 ± 4.4 and 72.7 ± 3.1 throws, respectively, P = .003). Postexercise plasma lactate after each SJFT was higher in all experimental conditions than with PLA (P = .001). There was no significant difference in rating of perceived exertion across the conditions (P = .18).Conclusion:The results of the current study show that the combined supplementation of NaHCO3 + CAF increases judo performance compared with PLA.


2021 ◽  
Vol 11 (4) ◽  
pp. 1756
Author(s):  
Shane Malone ◽  
Kieran Collins ◽  
Allistair McRobert ◽  
Dominic Doran

The current investigation quantified the training and match-play load of elite Gaelic football players across a two-season period using global positioning system technology (GPS), rating of perceived exertion (RPE) and sessional rating of perceived exertion (sRPE). Total weekly workload variables were collected across GPS, RPE, and sRPE across thirty-six elite Gaelic footballers (mean ± SD, age: 26 ± 5 years; height: 177 ± 8 cm; mass: 81 ± 7 kg) from one elite squad during a two-season observational period. External training load variables included: Total distance (m), High speed running (m; ≥ 17.1 km·h−1), Sprint distance (m; 22 km·h−1), Accelerations (n), Average metabolic power (W·kg−1), High-power distance (m; ≥ 25 W·kg−1). Internal load variables included: sRPE and RPE. Repeated measures ANOVA were used to understand the differences in loading patterns across phases, position, and week types when significant main effects were observed a Tukey’s post hoc test was applied and standardized effect sizes were calculated to understand the practical meaning of these differences. When total weekly loading across phases was considered total load was significantly greater in club 1 and provincial 1 with these phases showing the highest loading for players when compared to all other phases (p ≤ 0.001; ES: 2.95–7.22; very large). Furthermore, in-season 1 was greater for total loading when compared to in-season 2 and both championship phases (p ≤ 0.05; ES: 0.47–0.54; small). Total distance in training was greater during preseason 1 when compared to all other phases of the season (p ≤ 0.001; ES: 2.95–7.22; very large). During the in-season period, training based total distance was higher during provincial 1 when compared to other phases with similar trends across all measures (p ≤ 0.005). Finally, a positional profile for load measures was observed, with weekly context (match or non-match) having an impact on the internal and external loading players experienced across phases. The current data provide useful information for practitioners on the training periodization currently present within the elite Gaelic football training process. Specifically, the data provide positional profiles of loading across weekly and segmented phased of an elite Gaelic football season. These data can increase understanding as to the periods of increased and decreased loading across different phases of an elite Gaelic football season, while providing a framework for future analysis concerning Gaelic football periodization.


2018 ◽  
Vol 13 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Marco J. Konings ◽  
Jordan Parkinson ◽  
Inge Zijdewind ◽  
Florentina J. Hettinga

Purpose: Performing against a virtual opponent has been shown to invite a change in pacing and improve time-trial (TT) performance. This study explored how this performance improvement is established by assessing changes in pacing, neuromuscular function, and perceived exertion. Methods: After a peak-power-output test and a familiarization TT, 12 trained cyclists completed two 4-km TTs in randomized order on a Velotron cycle ergometer. TT conditions were riding alone (NO) and riding against a virtual opponent (OP). Knee-extensor performance was quantified before and directly after the TT using maximal voluntary contraction force (MVC), voluntary activation (VA), and potentiated doublet-twitch force (PT). Differences between the experimental conditions were examined using repeated-measures ANOVAs. Linear-regression analyses were conducted to associate changes in pacing to changes in MVC, VA, and PT. Results: OP was completed faster than NO (mean power output OP 289.6 ± 56.1 vs NO 272.2 ± 61.6 W; P = .020), mainly due to a faster initial pace. This was accompanied by a greater decline in MVC (MVC pre vs post −17.5% ± 12.4% vs −11.4% ± 10.9%, P = .032) and PT (PT pre vs post −23.1% ± 14.0% vs −16.2% ±11.4%, P = .041) after OP than after NO. No difference between conditions was found for VA (VA pre vs post −4.9% ± 6.7% vs −3.4% ± 5.0%, P = .274). Rating of perceived exertion did not differ between OP and NO. Conclusion: The improved performance when racing against a virtual opponent was associated with a greater decline in voluntary and evoked muscle force than riding alone, without a change in perceived exertion, highlighting the importance of human–environment interactions in addition to one’s internal state for pacing regulation and performance.


Author(s):  
Rafael Oliveira ◽  
Alexandre Martins ◽  
Hadi Nobari ◽  
Matilde Nalha ◽  
Bruno Mendes ◽  
...  

Abstract Background The interpretation of the load variations across a period seems important to control the weekly progression or variation of the load, or to identify within- micro and mesocycle variations. Thus, the aim of this study was to describe the in-season variations of training monotony, training strain, and acute: chronic workload ratio (ACWR) through session rating of perceived exertion (s-RPE), total distance and high-speed running (HSR) according to playing positions in an elite soccer team. Methods Seventeen professional players from an European First League team participated in this study. They were divided four central defenders (CD), three wide defenders (WD), four central midfielders (CM), three wide midfielders (WM) and three strikers (ST). The players were monitored daily over a 41-week period of competition where 52 matches occurred during the 2015–2016 in-season. Through the collection of s-RPE, total distance and HSR, training monotony, training strain and ACWR were calculated for each measure, respectively. Data were analysed across ten mesocycles (M: 1–10). Results The main results showed significant differences (p < 0.05) for TMs-RPE between CD vs. ST (moderate effect) in M2; between CD vs. CM (moderate effect) for TS of s-RPE; between CD vs. ST moderate effect) in M6 for ACWR of s-RPE. In addition, there was significant difference between CM vs. ST (moderate effect) in M2 for TS of TD; between WD vs. ST (moderate effect) in M3 for ACWR of TD. Moreover, there were significant differences for TM of HSR between CD vs. WD (very large effect); CD vs. WD (moderate effect) in M4 for TS of HSR. Conclusions The present study presents new insights to coaches and technical staff about the variation profiling of TM, TS, and ACWR calculated with internal and external load measures, between player positions during 10 mesocycles.


2018 ◽  
Vol 13 (8) ◽  
pp. 1059-1066 ◽  
Author(s):  
Mathieu Lacome ◽  
Christopher Carling ◽  
Jean-Philippe Hager ◽  
Gerard Dine ◽  
Julien Piscione

Purpose:To examine the effects of an intensified tournament on workload, perceptual and neuromuscular fatigue, and muscle-damage responses in an international under-20 rugby union team.Methods:Players were subdivided into a high-exposure group (HEG, n = 13) and a low-exposure group (LEG, n = 11) according to match-play exposure time. Measures monitored over the 19-d period included training session (n = 10) and match (n = 5) workload determined via global positioning systems and session rating of perceived exertion. Well-being scores, countermovement jump height performance, and blood creatine kinase concentrations were collected at various time points.Results:Analysis of workload cumulated across the tournament entirety for training and match play combined showed that high-speed running distance was similar between groups, while a very likely larger session rating of perceived exertion load was reported in HEG vs LEG. In HEG, high-speed activity fluctuated across the 5 successive matches, albeit with no clear trend for a progressive decrease. No clear tendency for a progressive decrease in well-being scores prior to or following matches was observed in either group. In HEG, trivial to possibly small reductions in postmatch countermovement jump performance were observed, while unclear to most likely moderate increases in prematch blood creatine kinase concentrations occurred until prior to match 4.Conclusions:The magnitude of match-to-match changes in external workload, perceptual and neuromuscular fatigue, and muscle damage was generally unclear or small. These results suggest that irrespective of exposure time to match play players generally maintained performance and readiness to play across the intensified tournament. These findings support the need for holistic systematic player-monitoring programs.


2012 ◽  
Vol 21 (2) ◽  
pp. 175-181 ◽  
Author(s):  
Kenji Masumoto ◽  
Ayako Hamada ◽  
Hiro-omi Tomonaga ◽  
Kana Kodama ◽  
Noboru Hotta

Context:Walking in water has been included in rehabilitation programs. However, there is a dearth of information regarding the influence of a water current on physiological responses, rating of perceived exertion (RPE), and stride characteristics of subjects while they walk in water.Objective:To compare physiological responses, RPE, and stride characteristics of subjects walking in water (with and without a current) with those of subjects walking on dry land.Design:Repeated measures.Setting:University laboratory.Participants:7 male adults (mean age = 21.6 y).Intervention:Subjects walked on a treadmill on dry land and on an underwater treadmill immersed to the level of the xiphoid process. The walking speeds in water were set to be half of that on dry land.Main Outcome Measures:Oxygen consumption (VO2), respiratory-exchange ratio (RER), heart rate (HR), minute ventilation (VE), RPE (for breathing and legs, RPE-Br and RPE-Legs, respectively), systolic (SBP) and diastolic (DBP) blood pressures, and stride frequency (SF) were measured. In addition, stride length (SL) was calculated.Results:There was no significant difference in the VO2, RER, HR, VE, RPE-Br, and RPE-Legs while walking in water with a current compared with walking on dry land (P > .05). Furthermore, VO2, RER, HR, VE, RPE-Br, RPE-Legs, SF, and SBP while walking in water were significantly higher with a water current than without (P < .05).Conclusions:These observations suggest that half the speed should be required to work at the similar metabolic costs and RPE while walking in water with a current, compared with walking on dry land. Furthermore, it was suggested that the physiological responses and RPE would be higher while walking in water with a current than without.


2018 ◽  
Vol 13 (7) ◽  
pp. 891-896 ◽  
Author(s):  
Barry S. Mason ◽  
Rienk M.A. van der Slikke ◽  
Michael J. Hutchinson ◽  
Monique A.M. Berger ◽  
Victoria L. Goosey-Tolfrey

Purpose: To examine the effects of different small-sided games (SSGs) on physical and technical aspects of performance in wheelchair basketball (WB) players. Design: Observational cohort study. Methods: Fifteen highly trained WB players participated in a single 5v5 (24-s shot clock) match and three 3v3 SSGs (18-s shot clock) on a (1) full court, (2) half-court, and (3) modified-length court. During all formats, players’ activity profiles were monitored using an indoor tracking system and inertial measurement units. Physiological responses were monitored via heart rate and rating of perceived exertion. Technical performance, that is, ball handling, was monitored using video analysis. Repeated-measures analysis of variance and effect sizes (ESs) were calculated to determine the statistical significance and magnitude of any differences between game formats. Results: Players covered less distance and reached lower peak speeds during half-court (P ≤ .0005; ES ≥ very large) compared with all other formats. Greater distances were covered, and more time was spent performing moderate- and high-speed activity (P ≤ .008; ES ≥ moderate) during full court compared with all other formats. Game format had little bearing on physiological responses, and the only differences in technical performance observed were in relation to 5v5. Players spent more time in possession, took more shots, and performed more rebounds in all 3v3 formats compared with 5v5 (P ≤ .028; ES ≥ moderate). Conclusions: Court dimensions affect the activity profiles of WB players during 3v3 SSGs yet had little bearing on technical performance when time pressures (shot clocks) were constant. These findings have important implications for coaches to understand which SSG format may be most suitable for physically and technically preparing WB players.


2018 ◽  
Vol 3 (4) ◽  
pp. 60 ◽  
Author(s):  
Ramires Tibana ◽  
Nuno de Sousa ◽  
Jonato Prestes ◽  
Fabrício Voltarelli

The aim of this study was to analyze blood lactate concentration (LAC), heart rate (HR), and rating perceived exertion (RPE) during and after shorter and longer duration CrossFit® sessions. Nine men (27.7 ± 3.2 years; 11.3 ± 4.6% body fat percentage and training experience: 41.1 ± 19.6 months) randomly performed two CrossFit® sessions (shorter: ~4 min and longer: 17 min) with a 7-day interval between them. The response of LAC and HR were measured pre, during, immediately after, and 10, 20, and 30 min after the sessions. RPE was measured pre and immediately after sessions. Lactate levels were higher during the recovery of the shorter session as compared with the longer session (shorter: 15.9 ± 2.2 mmol/L/min, longer: 12.6 ± 2.6 mmol/L/min; p = 0.019). There were no significant differences between protocols on HR during (shorter: 176 ± 6 bpm or 91 ± 4% HRmax, longer: 174 ± 3 bpm or 90 ± 3% HRmax, p = 0.387). The LAC was significantly higher throughout the recovery period for both training sessions as compared to pre-exercise. The RPE was increased immediately after both sessions as compared to pre-exercise, while there was no significant difference between them (shorter: 8.7 ± 0.9, longer: 9.6 ± 0.5; p = 0.360). These results demonstrated that both shorter and longer sessions induced elevated cardiovascular responses which met the recommendations for gains in cardiovascular fitness. In addition, both training sessions had a high metabolic and perceptual response, which may not be suitable if performed on consecutive days.


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