Interrelationship between specific high-intensity intermittent efforts ability with aerobic capacity and slow stretch-shortening cycle utilization in taekwondo athletes

2021 ◽  
pp. 1-10
Author(s):  
Alex Ojeda-Aravena ◽  
Tomás Herrera-Valenzuela ◽  
Pablo Valdés-Badilla ◽  
Eduardo Baez-San Martín ◽  
José Zapata-Bastías ◽  
...  
Keyword(s):  
Aerobic Capacity ◽  
High Intensity ◽  
Dynamic Strength ◽  
Multiple Regression Model ◽  
Strength Index ◽  
Male Athletes ◽  
Squat Jump ◽  
Stretch Shortening Cycle ◽  
The Relationship ◽  
Shuttle Run

BACKGROUND: Repeat high-intensity intermittent efforts is a taekwondo-specific ability but the influence of aerobic capacity and dynamic strength characteristics on this ability has received relatively little attention in the literature. OBJECTIVE: To examine the relationship between specific high-intensity intermittent efforts with aerobic capacity and slow stretch-shortening cycle utilization in taekwondo athletes. METHODS: Nineteen taekwondo male athletes were assessed by squat jump (SJ), countermovement jump (CMJ), 20-meter shuttle run (20MSR), and frequency speed of kick test multiple (FSKTMULT). From the FSKTMULT, total kicks and kick decrement index [KDI] were calculated. Additionally, from both jump tests, the slow stretch-shortening cycle utilization (Slow SSC Utilization) was determined from the eccentric utilization ratio [EUR], pre-stretch augmentation [PSA], and reactive strength index [RSI]. RESULTS: There were positive and significant correlations between total kicks with 20MSR (r= 0.85; p= 0.00) and SJ (r= 0.66; p< 0.05). The multiple regression model demonstrated that total kicks where significantly influenced by 20MSR (R2= 71%; p= 0.00). Additionally, only EUR and RSI explained total kicks performance to a greater proportion (R2= 76%). CONCLUSIONS: The FSKTMULT total kicks performance is positively correlated and influenced by aerobic capacity and slow SSC utilization.

Relationship between explosive strength characteristics with change of direction speed in junior and cadet karate athletes

2021 ◽  
pp. 1-10
Author(s):  
Alex Ojeda-Aravena ◽  
Tomás Herrera-Valenzuela ◽  
Pablo Valdés-Badilla ◽  
Jairo Azócar-Gallardo ◽  
Victor Campos-Uribe ◽  
...  
Keyword(s):  
Multiple Regression Model ◽  
Superior Performance ◽  
Percentage Increase ◽  
Strength Index ◽  
Squat Jump ◽  
Change Of Direction ◽  
Explosive Strength ◽  
Physical Abilities ◽  
The Relationship ◽  
Karate Athletes

BACKGROUND: Explosive strength and change of direction speed (CODS) are relevant physical abilities in karate. OBJECTIVE: To examine the relationship between the characteristics of explosive strength and the 5-m linear sprint (5M) with CODS performance and ii) to examine the influential characteristics of explosive strength on CODS performance. METHODS: Eighteen cadet and junior karate athletes, eight females and ten males were evaluated. The physical abilities assessments included: squat jump (SJ), countermovement jump (CMJ), 5M and CODS. Also, pre-stretch percentage increase (PSA), eccentric utilization index (EUR) reactive strength index (RSI) were calculated. RESULTS: Superior performance (p< 0.05) was documented in SJ, CMJ and CODS in male vs. female. Also, significant correlations between CODS with SJ and CMJ (r=-0.70 to -0.80; R2=-0.51 to -0.73; p< 0.05, respectively) and correlations (r=-0.14 to -0.22; R2= 0.01 to 0.04; p> 0.05) between CODS with RSI, EUR and PSA. Multiple regression model documented that only SJ significantly influenced CODS performance in male (R2= 60%; p= 0.009) and female (R2= 71%; p= 0.001). CONCLUSION: CODS correlate with SJ and CMJ. In particular, SJ influence CODS independently of gender.

Leg Strength Is Related to Endurance Run Performance in Children and Adolescents with Mental Retardation

2000 ◽  
Vol 12 (3) ◽  
pp. 324-333 ◽  
Author(s):  
Bo Fernhall ◽  
Kenneth H. Pitetti
Keyword(s):  
Mental Retardation ◽  
Body Size ◽  
Children And Adolescents ◽  
Aerobic Capacity ◽  
Significant Influence ◽  
Moderate Mental Retardation ◽  
Leg Strength ◽  
And Gender ◽  
The Relationship ◽  
Shuttle Run

This study evaluated the relationship between leg strength and endurance run performance, independent of aerobic capacity (V̇O2peak), body size, and gender, in children and adolescents with mild or moderate mental retardation. Twenty-six individuals (15 boys and 11 girls) volunteered and underwent tests of V̇O2peak, isokinetic leg strength, and endurance run performance (600-yard ran/walk and 20-m shuttle run). Results showed that leg strength was significantly related to both types of run performance; however, when controlling for V̇O2peak, body size, and gender, leg strength was a more significant contributor to the 600-yard run/walk than to 20-m shuttle run performance. Gender did not influence these relationships. These data suggest that leg strength has a significant influence on endurance run performance in children and adolescents with mild or moderate mental retardation.

scholarly journals The Relationship Between Body Compositions of Taekwondo Practitioners Aged 14-16 and Their Aerobic Endurance

2021 ◽  
Vol 15 (10) ◽  
pp. 3438-3440
Author(s):  
Duygu Sevinç Yilmaz ◽  
Burakhan Aydemir
Keyword(s):  
Body Composition ◽  
Aerobic Capacity ◽  
Pearson Correlation ◽  
The Body ◽  
Performance Criteria ◽  
Fat Percentage ◽  
Run Test ◽  
Body Compositions ◽  
The Relationship ◽  
Shuttle Run

Background: Taekwondo (TKD) is a combat sport practiced by millions of children, young people and adults around the world.1 It is an Olympic sports branch with many complex features and constant interaction between two opponents in the competitions, where attack-contact techniques are applied quickly, attacking techniques are strong2,3 but also have good flexibility. Aim: This study has been carried out to identify the relationship between body composition of taekwondo practitioners aged 14-16 who regularly practice taekwondo, and their aerobic endurance. Methods: A total of 33 registered taekwondo practitioners (17 male, 16 female) participated to this study on a voluntary basis. The age, height, weight, and body mass index of all the athletes who took part in the study are 14.96±0.80 years, 162.59±11.59 cm, 50.97±7.51 kg and 19.14±2.39 kg/m² respectively. The group who participated to the study practice taekwondo two days a week, for 2 hours each, for a period of 1.5 years. The aerobic endurance of taekwondo athletes was measured by 20-meter-long Shuttle Run Test. In order to measure the body composition values of the athletes, measurements of skinfold thickness (biceps, triceps, subscapula, subrailiac) were carried out. In calculating the body density, the formula of Durning-Womersley was used; and in calculating the body fat percentage, the formula of Siri was employed. Data was evaluated by SPSS 22.0. The normality distribution of the data obtained at the end of the study was evaluated by Kolmogorov-Smirnov test and it was observed that the data was in line with normal distribution. Following the normalcy assessment, the relationship between body compositions and aerobic endurances was determined by Pearson Correlation analysis. Results: It is possible to say that the body composition values of taekwondo practitioners aged 14-16 have positive and negative impact on their aerobic endurance. It is observed that as the values 20-meter Shuttle Run test increases, fat percentage of athletes decreases. Conclusion: It is concluded that the findings obtained from the research results support the literature, and that body composition and aerobic capacity are important as performance criteria in many studies. It is thought that it may be beneficial for the athletes to perform aerobic endurance exercises during the annual training periods to perform the necessary practices to optimize their body composition and improve their aerobic capacity. Keywords: Taekwondo, Body Composition, Aerobic Endurance

The Relationship Between Maximal Strength and Reactive Strength

2017 ◽  
Vol 12 (4) ◽  
pp. 548-553 ◽  
Author(s):  
Kris Beattie ◽  
Brian P. Carson ◽  
Mark Lyons ◽  
Ian C. Kenny
Keyword(s):  
Pearson Correlation ◽  
Peak Force ◽  
Maximum Strength ◽  
Group Differences ◽  
Drop Jump ◽  
Maximal Strength ◽  
Strength Index ◽  
Stretch Shortening Cycle ◽  
The Relationship ◽  
Sporting Performance

Maximum- and reactive-strength qualities both have important roles in athletic movements and sporting performance. Very little research has investigated the relationship between maximum strength and reactive strength. The aim of this study was to investigate the relationship between maximum-strength (isometric midthigh-pull peak force [IMTP PF]) and reactive-strength (drop-jump reactive-strength index [DJ-RSI]) variables at 0.3-m, 0.4-m, 0.5-m, and 0.6-m box heights. A secondary aim was to investigate the between- and within-group differences in reactive-strength characteristics between relatively stronger athletes (n = 11) and weaker athletes (n = 11). Forty-five college athletes across various sports were recruited to participate in the study (age, 23.7 ± 4.0 y; mass, 87.5 ± 16.1 kg; height, 1.80 ± 0.08 m). Pearson correlation results showed that there was a moderate association (r = .302–.431) between maximum-strength variables (absolute, relative, and allometric scaled PF) and RSI at 0.3, 0.4, 0.5 and 0.6 m (P ≤ .05). In addition, 2-tailed independent-samples t tests showed that the RSIs for relatively stronger athletes (49.59 ± 2.57 N/kg) were significantly larger than those of weaker athletes (33.06 ± 2.76 N/kg) at 0.4 m (Cohen d = 1.02), 0.5 m (d = 1.21), and 0.6 m (d = 1.39) (P ≤ .05). Weaker athletes also demonstrated significant decrements in RSI as eccentric stretch loads increased at 0.3-m through 0.6-m box heights, whereas stronger athletes were able to maintain their reactive-strength ability. This research highlights that in specific sporting scenarios, when there are high eccentric stretch loads and fast stretch-shortening-cycle demands, athletes’ reactive-strength ability may be dictated by their relative maximal strength, specifically eccentric strength.

Using Bar Velocity to Predict Maximum Dynamic Strength in the Half-Squat Exercise

2016 ◽  
Vol 11 (5) ◽  
pp. 697-700 ◽  
Author(s):  
Irineu Loturco ◽  
Lucas A. Pereira ◽  
Cesar C. Cal Abad ◽  
Saulo Gil ◽  
Katia Kitamura ◽  
...  
Keyword(s):  
Dynamic Strength ◽  
American Football ◽  
Soccer Players ◽  
Combat Sport ◽  
Male Athletes ◽  
Squat Exercise ◽  
Bar Velocity ◽  
High Degree ◽  
The Relationship ◽  
Strong Linear Relationship

Purpose:To determine whether athletes from different sport disciplines present similar mean propulsive velocity (MPV) in the half-squat (HS) during submaximal and maximal tests, enabling prediction of 1-repetition maximum (1-RM) from MPV at any given submaximal load.Methods:Sixty-four male athletes, comprising American football, rugby, and soccer players; sprinters and jumpers; and combat-sport strikers attended 2 testing sessions separated by 2–4 wk. On the first visit, a standardized 1-RM test was performed. On the second, athletes performed HSs on Smith-machine equipment, using relative percentages of 1-RM to determine the respective MPV of submaximal and maximal loads. Linear regression established the relationship between MPV and percentage of 1-RM.Results:A very strong linear relationship (R2 ≈ .96) was observed between the MPV and the percentages of HS 1-RM, resulting in the following equation: %HS 1-RM = −105.05 × MPV + 131.75. The MPV at HS 1-RM was ~0.3 m/s.Conclusion:This equation can be used to predict HS 1-RM on a Smith machine with a high degree of accuracy.

scholarly journals The prediction of swim start performance based on squat jump force-time characteristics

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9208
Author(s):  
Shiqi Thng ◽  
Simon Pearson ◽  
Evelyne Rathbone ◽  
Justin W.L. Keogh
Keyword(s):  
Body Mass ◽  
National Level ◽  
Multiple Regression Model ◽  
Lower Body ◽  
Strength Index ◽  
Mean Power ◽  
Front Crawl ◽  
Jump Performance ◽  
Squat Jump ◽  
Force Time

Background Depending on the stroke and distances of the events, swim starts have been estimated to account for 0.8% to 26.1% of the overall race time, with the latter representing the percentage in a 50 m sprint front crawl event (Cossor & Mason, 2001). However, it is still somewhat unclear what are the key physiological characteristics underpinning swim start performance. The primary aim of this study was to develop a multiple regression model to determine key lower body force-time predictors using the squat jump for swim start performance as assessed by time to 5 m and 15 m in national and international level swimmers. A secondary aim was to determine if any differences exist between males and females in jump performance predictors for swim start performance. Methods A total of 38 males (age 21 ±  3.1 years, height 1.83 ±  0.08 m, body mass 76.7 ±  10.2 kg) and 34 females (age 20.1 ±  3.2 years, height 1.73 ±  0.06 m, body mass 64.8 ±  8.4 kg) who had competed at either an elite (n = 31) or national level (n = 41) participated in this study. All tests were performed on the same day, with participants performing three bodyweight squat jumps on a force platform, followed by three swim starts using their main swimming stroke. Swim start performance was quantified via time to 5 m and 15 m using an instrumented starting block. Results Stepwise multiple linear regression with quadratic fitting identified concentric impulse and concentric impulse2 as statistically significant predictors for time to 5 m (R2 = 0.659) in males. With time to 15 m, concentric impulse, age and concentric impulse2 were statistically significant predictors for males (R2 = 0.807). A minimum concentric impulse of 200–230 N.s appears required for faster times to 5 m and 15 m, with any additional impulse production not being associated with a reduction in swim start times for most male swimmers. Concentric impulse, Reactive strength index modified and concentric mean power were identified as statistically significant predictors for female swimmers to time to 5 m (R2 = 0.689). Variables that were statistically significant predictors of time to 15 m in females were concentric impulse, body mass, concentric rate of power development and Reactive strength index modified (R2 = 0.841). Discussion The results of this study highlight the importance of lower body power and strength for swim start performance, although being able to produce greater than 200 or 230 N.s concentric impulse in squat jump did not necessarily increase swim start performance over 5 m and 15 m, respectively. Swimmers who can already generate greater levels of concentric impulse may benefit more from improving their rate of force development and/or technical aspects of the swim start performance. The sex-related differences in key force-time predictors suggest that male and female swimmers may require individualised strength and conditioning programs and regular monitoring of performance.

scholarly journals Inter-Individual Variability of a High-Intensity Interval Training With Specific Techniques vs. Repeated Sprints Program in Sport-Related Fitness of Taekwondo Athletes

2021 ◽  
Vol 12 ◽  
Author(s):  
Alex Ojeda-Aravena ◽  
Tomás Herrera-Valenzuela ◽  
Pablo Valdés-Badilla ◽  
Jorge Cancino-López ◽  
José Zapata-Bastias ◽  
...  
Keyword(s):  
High Intensity ◽  
Interval Training ◽  
Individual Variability ◽  
Size Analysis ◽  
High Intensity Interval Training ◽  
Squat Jump ◽  
Repeated Sprints ◽  
High Intensity Interval ◽  
Regular Training ◽  
Shuttle Run

This study investigated the effect of 4 weeks of high-intensity interval training (HIIT) with specific techniques (TS-G) vs. repeated sprints (RS-G) and analyzed the inter-individual variability [classified into responders (Rs) and non-responders (NRs)] on sport-related fitness in taekwondo (TKD) athletes. Athletes of both genders (n = 12) were randomly assigned into TS-G and RS-G groups. Both groups trained 3 days/week for 4 weeks [two blocks of three rounds of 2 min of activity (4-s of all-out efforts with 28-s dynamical pauses) with 1 min of recovery in between and 5 min between blocks] during their regular training. The related sport fitness assessments included squat jump (SJ), countermovement jump (CMJ), multiple frequency speed of kick test (FSKTMULT), specifically total kicks and Kick Decrement Index (KDI), and 20-m shuttle run (20MSR). Relevant results indicate a significant effect of the time factor in both groups for SJ performance and a significant decrease for KDI in RS-G. In addition, an improvement in performance according to the effect size analysis in the TS-G in total kicks, KDI, and 20MSR. Complementarily, a higher proportion of athlete Rs was reported in TS-G vs. RS-G for SJ (50% vs. 30.3%, respectively), CMJ, and total kicks (16.6% vs. 0%). In conclusion, the addition to the regular training of a HIIT with specific-techniques and repeated-sprints associated with intervals and similar structure of the combat during 4 weeks of training can improve the concentric characteristics of lower limb performance, although they were not the sufficient stimuli in the other components of TKD-related fitness.

scholarly journals Comparison of Methods of Calculating Dynamic Strength Index

2018 ◽  
Vol 13 (3) ◽  
pp. 320-325 ◽  
Author(s):  
Paul Comfort ◽  
Christopher Thomas ◽  
Thomas Dos’Santos ◽  
Paul A. Jones ◽  
Timothy J. Suchomel ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Dynamic Strength ◽  
Rugby League ◽  
Strength Index ◽  
Countermovement Jump ◽  
Reliable Measure ◽  
Male Youth ◽  
Squat Jump ◽  
Youth Soccer ◽  
Very High

Purpose: To determine the reliability and variability of the Dynamic Strength Index (DSI) calculated from squat-jump (SJ) vs countermovement-jump (CMJ) peak force (PF) and to compare DSI values between methods. Methods: Male youth soccer and rugby league players (N = 27; age 17.2 ± 0.7 y, height 173.9 ± 5.7 cm, body mass 71.1 ± 7.2 kg) performed 3 trials of the SJ, CMJ, and isometric midthigh pull (IMTP) on 2 separate days. DSI was calculated by dividing the PF during each jump by the IMTP PF. Results: DSI-SJ exhibited moderate (intraclass correlation coefficient [ICC] = .419) within-session reliability and high variability (percentage coefficient of variation [%CV] = 15.91) during session 1; however, this improved noticeably during session 2 (ICC = .948, %CV = 4.03). In contrast, DSI-CMJ showed nearly perfect within-session reliability (ICC = .920–.952) and low variability (%CV = 3.80–4.57) for both sessions. Moreover, DSI-SJ values demonstrated a small yet significant increase between sessions (P = .01, d = 0.37), whereas only a trivial and nonsignificant increase was observed for DSI-CMJ between sessions (P = .796, d = 0.07). Between-sessions reliability was very high for the DSI-SJ (ICC = .741) and nearly perfect for the DSI-CMJ (ICC = .924). There was no significant or meaningful difference (P = .261, d = 0.12) between DSI-SJ (0.82 ± 0.18) and DSI-CMJ (0.84 ± 0.15). Conclusions: Practitioners should use DSI-CMJ, as it is a more reliable measure than DSI-SJ, although it produces similar ratios.

Comparing the Effects of Immersed Versus Land-Based High-Intensity Interval Cycling on Energy Intake, Appetite Sensations and Perceived Exertion Among Healthy Men

2021 ◽  
pp. 003151252110073
Author(s):  
Lore Metz ◽  
Laurie Isacco ◽  
Maud Miguet ◽  
Pauline Genin ◽  
David Thivel ◽  
...  
Keyword(s):  
Energy Intake ◽  
High Intensity ◽  
Perceived Exertion ◽  
Area Under The Curve ◽  
Macronutrient Intake ◽  
Healthy Men ◽  
High Intensity Interval ◽  
Interval Cycling ◽  
Desire To Eat ◽  
The Relationship

Immersed exercise has been shown to induce higher energy expenditure and no difference or increase in food intake compared with similar exercise on land. In this study, we compared the effects of acute high-intensity cycling performed on land versus when immersed on subsequent energy intake (EI), appetite sensations and perceived exertion (RPE) in healthy men. Ten participants in a postprandial condition completed three experimental visits in a randomized order: a control condition (CONT); a high-intensity interval cycling exercise performed on land (HIIE-L) and the same exercise while immersed in water (HIIE-A) with a similar targeted heart rate. We observed no difference in energy and macronutrient intake and in area under the curve (AUC) for appetite sensations between sessions. The RPE at the end of HIIE-L was negatively correlated with EI (r=–0.67; p < 0.05), AUC for hunger (r=–0.86, p < 0.01), desire to eat (r=–0.78, p < 0.05) and prospective food consumption (r=–0.86, p < 0.01). Conversely, the RPE at the end of HIIE-L was positively correlated with AUC for fullness (r = 0.76 , p < 0.05). No such correlations were observed for HIIE-A. The present study was the first to observe that immersion did not influence EI after HIIE cycling, but immersion blunted the relationship between session RPE and subsequent energy intake and appetite sensations relative to HIIE on land.

Sign in / Sign up

Export Citation Format

Share Document