scholarly journals Acute Effects of Different Plyometric and Strength Exercises on Balance Performance in Youth Weightlifters

2021 ◽  
Vol 12 ◽  
Author(s):  
Hanen Werfelli ◽  
Raouf Hammami ◽  
Mohamed Amine Selmi ◽  
Walid Selmi ◽  
Goran Gabrilo ◽  
...  

Background: High-intensity muscle actions have the potential to temporarily improve the performance which has been denoted as postactivation performance enhancement.Objectives: This study determined the acute effects of different stretch-shortening (fast vs. low) and strength (dynamic vs. isometric) exercises executed during one training session on subsequent balance performance in youth weightlifters.Materials and Methods: Sixteen male and female young weightlifters, aged 11.3±0.6years, performed four strength exercise conditions in randomized order, including dynamic strength (DYN; 3 sets of 3 repetitions of 10 RM) and isometric strength exercises (ISOM; 3 sets of maintaining 3s of 10 RM of back-squat), as well as fast (FSSC; 3 sets of 3 repetitions of 20-cm drop-jumps) and slow (SSSC; 3 sets of 3 hurdle jumps over a 20-cm obstacle) stretch-shortening cycle protocols. Balance performance was tested before and after each of the four exercise conditions in bipedal stance on an unstable surface (i.e., BOSU ball with flat side facing up) using two dependent variables, i.e., center of pressure surface area (CoP SA) and velocity (CoP V).Results: There was a significant effect of time on CoP SA and CoP V [F(1,60)=54.37, d=1.88, p<0.0001; F(1,60)=9.07, d=0.77, p=0.003]. In addition, a statistically significant effect of condition on CoP SA and CoP V [F(3,60)=11.81, d=1.53, p<0.0001; F(3,60)=7.36, d=1.21, p=0.0003] was observed. Statistically significant condition-by-time interactions were found for the balance parameters CoP SA (p<0.003, d=0.54) and CoP V (p<0.002, d=0.70). Specific to contrast analysis, all specified hypotheses were tested and demonstrated that FSSC yielded significantly greater improvements than all other conditions in CoP SA and CoP V [p<0.0001 (d=1.55); p=0.0004 (d=1.19), respectively]. In addition, FSSC yielded significantly greater improvements compared with the two conditions for both balance parameters [p<0.0001 (d=2.03); p<0.0001 (d=1.45)].Conclusion: Fast stretch-shortening cycle exercises appear to be more effective to improve short-term balance performance in young weightlifters. Due to the importance of balance for overall competitive achievement in weightlifting, it is recommended that young weightlifters implement dynamic plyometric exercises in the fast stretch-shortening cycle during the warm-up to improve their balance performance.

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Thomas Muehlbauer ◽  
Leander Abel ◽  
Simon Schedler ◽  
Stefan Panzer

Abstract Objective While there is evidence on the short-term effects of unilateral balance training (BT) on bipedal balance performance, less is known on the acute effects of unilateral BT on unilateral (i.e., ipsi- and contralateral) balance performance. Thus, the present study examined the acute effects of a single unilateral BT session conducted with the non-dominant, left leg or the dominant, right leg on ipsilateral (i.e. retention) and contralateral (i.e., inter-limb transfer) balance performance in healthy young adults (N = 28). Results Irrespective of practice condition, significant improvements (p < 0.001, d = 1.27) in balance performance following a single session of unilateral BT were observed for both legs. Further, significant performance differences at the pretest (p = 0.002, d = 0.44) to the detriment of the non-dominant, left leg diminished immediately and 30 min after the single unilateral BT session but occurred again 24 h following training (p = 0.030, d = 0.36). These findings indicate that a single session of unilateral BT is effective to reduced side-to-side differences in balance performance, but this impact is only temporary.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ziyou Zhou ◽  
Can Wu ◽  
Zhen Hu ◽  
Yujuan Chai ◽  
Kai Chen ◽  
...  

AbstractIt has been known that short-time auditory stimulation can contribute to the improvement of the balancing ability of the human body. The present study aims to explore the effects of white Gaussian noise (WGN) of different intensities and frequencies on dynamic balance performance in healthy young adults. A total of 20 healthy young participants were asked to stand at a dynamic balance force platform, which swung along the x-axis with an amplitude of ± 4° and frequency of 1 Hz. Their center of pressure (COP) trajectories were recorded when they were stimulated by WGN of different intensities (block 1) and different frequencies (block 2). A traditional method and detrended fluctuation analysis (DFA) were used for data preprocessing. The authors found that only with 75–85 dB WGN, the COP parameters improved. WGN frequency did not affect the dynamic balance performance of all the participants. The DFA results indicated stimulation with 75 dB WGN enhanced the short-term index and reduced the crossover point. Stimulation with 500 Hz and 2500 Hz WGN significantly enhanced the short-term index. These results suggest that 75 dB WGN and 500 Hz and 2500 Hz WGN improved the participants’ dynamic balance performance. The results of this study indicate that a certain intensity of WGN is indispensable to achieve a remarkable improvement in dynamic balance. The DFA results suggest that WGN only affected the short-term persistence, indicating the potential of WGN being considered as an adjuvant therapy in low-speed rehabilitation training.


Author(s):  
Nuno Batalha ◽  
Jose A. Parraca ◽  
Daniel A. Marinho ◽  
Ana Conceição ◽  
Hugo Louro ◽  
...  

The purpose of this study was to analyze the acute effects of a standardized water training session on the shoulder rotators strength and balance in age group swimmers, in order to understand whether a muscle-strengthening workout immediately after the water training is appropriate. A repeated measures design was implemented with two measurements performed before and after a standardized swim session. 127 participants were assembled in male (n = 72; age: 16.28 ± 1.55 years, height: 174.15 ± 7.89 cm, weight: 63.97 ± 6.51 kg) and female (n = 55; age: 15.29 ± 1.28 years, height: 163.03 ± 7.19 cm, weight: 52.72 ± 5.48 kg) cohorts. The isometric torque of the shoulder internal (IR) and external (ER) rotators, as well as the ER/IR ratios, were assessed using a hand-held dynamometer. Paired sample t-tests and effect sizes (Cohen’s d) were used (p ≤ 0.05). No significant differences were found on the shoulder rotators strength or balance in males after training. Females exhibited unchanged strength values after practice, but there was a considerable decrease in the shoulder rotators balance of the non-dominant limb (p < 0.01 d = 0.366). This indicates that a single practice seems not to affect the shoulders strength and balance of adolescent swimmers, but this can be a gender specific phenomenon. While muscle-strengthening workout after the water session may be appropriate for males, it can be questionable regarding females. Swimming coaches should regularly assess shoulder strength levels in order to individually identify swimmers who may or may not be able to practice muscle strengthening after the water training.


2015 ◽  
Vol 113 (7) ◽  
pp. 2127-2136 ◽  
Author(s):  
Chia-Cheng Lin ◽  
Susan L. Whitney ◽  
Patrick J. Loughlin ◽  
Joseph M. Furman ◽  
Mark S. Redfern ◽  
...  

Vibrotactile feedback (VTF) has been shown to improve balance performance in healthy people and people with vestibular disorders in a single-task experimental condition. It is unclear how age-related changes in balance affect the ability to use VTF and if there are different attentional requirements for old and young adults when using VTF. Twenty younger and 20 older subjects participated in this two-visit study to examine the effect of age, VTF, sensory condition, cognitive task, duration of time, and visit on postural and cognitive performance. Postural performance outcome measures included root mean square of center of pressure (COP) and trunk tilt, and cognitive performance was assessed using the reaction time (RT) from an auditory choice RT task. The results showed that compared with younger adults, older adults had an increase in COP in fixed platform conditions when using VTF, although they were able to reduce COP during sway-referenced platform conditions. Older adults also did not benefit fully from using VTF in their first session. The RTs for the secondary cognitive tasks increased significantly while using the VTF in both younger and older adults. Older adults had a larger increase compared with younger adults, suggesting that greater attentional demands were required in older adults when using VTF information. Future training protocols for VTF should take into consideration the effect of aging.


2021 ◽  
Vol 27 (2) ◽  
pp. 69-76
Author(s):  
Devan Sedlacek ◽  
Matthew Beacom ◽  
Sabin R. Bista ◽  
Risto Rautiainen ◽  
Ka-Chun Siu

HighlightsThe farming population is at risk of injury due to sleep deprivation.Loss of sleep during previous night affects balance performance in farmers.Objective measures of sleep are more reliable than subjective measures for predicting balance performance.Abstract. This study aimed to investigate the ability of both subjective and objective sleep measures to predict balance difficulty in agricultural workers. Seven male farmers from rural Nebraska were analyzed for static balance performance following a bout of sleep. Actiwatches were used to measure objective sleep hours and subjective questionnaires, including the Epworth Sleepiness Scale and the Pittsburgh Sleep Quality Index, were used to measure subjective hours of sleep and sleep quality. The participants were observed for 12 sessions, with six in planting season and six in harvest season. Static balance testing consisted of measuring the area, total displacement, and maximum range in the anteroposterior and mediolateral directions of the individual’s center of pressure with Tekscan pressure mats. Overall, it was found that objective measures had a higher correlation with the magnitude of balance deviations than subjective measures. Keywords: Actiwatch, Agricultural worker, Injury, Sleep deprivation.


2021 ◽  
pp. 1-10
Author(s):  
Alex Ojeda-Aravena ◽  
Tomás Herrera-Valenzuela ◽  
Pablo Valdés-Badilla ◽  
Eduardo Baez-San Martín ◽  
José Zapata-Bastías ◽  
...  

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.


2019 ◽  
Vol 67 (1) ◽  
pp. 235-245
Author(s):  
Javier Fernández-Rio ◽  
Luis Santos ◽  
Benjamín Fernández-García ◽  
Roberto Robles ◽  
Iván Casquero ◽  
...  

AbstractThe goal of this study was to assess the effects of a supervised slackline training program in a group of soccer players. Thirty-four male division I under-19 players (16.64 ± 0.81 years) agreed to participate in the study. They were randomly divided into an experimental group (EG) and a control group (CG). The first group (EG) followed a 6-week supervised slackline training program (3 sessions/week; 5-9 min/session), while the CG performed only regular soccer training. Several variables were assessed in all participants: acceleration (20-m sprint test), agility (90º turns test), jump performance (squat jump, countermovement jump), and postural control (Center of Pressure ( CoP) testing: length, area, speed, Xmean, Ymean, Xspeed, Yspeed, Xdeviation, Ydeviation). Ratings of perceived exertion and local muscle ratings of perceived exertions were also recorded after each slackline training session. At post-tests, there was a significant increase only in the EG in acceleration, agility, squat jump and countermovement jump performance, as well as several CoP variables: area in the bipedal support on a firm surface, and length, area and speed in the left leg on a firm surface. The program was rated as “somewhat hard” by the players, while quadriceps, gastrocnemius and tibialis anterior were the most exerted muscles while slacklining. In conclusion, slackline training can be an effective training tool for young, high-level soccer players.


2021 ◽  
Vol 16 (1) ◽  
pp. 66-72
Author(s):  
Justin J. Merrigan ◽  
James J. Tufano ◽  
Michael Falzone ◽  
Margaret T. Jones

Purpose: To identify acute effects of a single accentuated eccentric loading (AEL) repetition on subsequent back-squat kinetics and kinematics with different concentric loads. Methods: Resistance-trained men (N = 21) participated in a counterbalanced crossover design and completed 4 protocols (sets × repetitions at eccentric/concentric) as follows: AEL65, 3 × 5 at 120%/65% 1-repetition maximum (1-RM); AEL80, 3 × 3 at 120%/80% 1-RM; TRA65, 3 × 5 at 65%/65% 1-RM; and TRA80, 3 × 3 at 80%/80% 1-RM. During AEL, weight releasers disengaged from the barbell after the eccentric phase of the first repetition and remained off for the remaining repetitions. All repetitions were performed on a force plate with linear position transducers attached to the barbell, from which eccentric and concentric peak and mean velocity, force, and power were derived. Results: Eccentric peak velocity (−0.076 [0.124] m·s−1; P = .01), concentric peak force (187.8 [284.4] N; P = .01), eccentric mean power (−145.2 [62.0] W; P = .03), and eccentric peak power (−328.6 [93.7] W; P < .01) during AEL65 were significantly greater than TRA65. When collapsed across repetitions, AEL65 resulted in slower eccentric velocity and power during repetition 1 but faster eccentric and concentric velocity and power in subsequent repetitions (P ≤ .04). When comparing AEL80 with TRA80, concentric peak force (133.8 [56.9] N; P = .03), eccentric mean power (−83.57 [38.0] W; P = .04), and eccentric peak power (−242.84 [67.3] W; P < .01) were enhanced. Conclusions: Including a single supramaximal eccentric phase of 120% 1-RM increased subsequent velocity and power with concentric loads of 65% 1-RM, but not 80% 1-RM. Therefore, AEL is sensitive to the magnitude of concentric loads, which requires a large relative difference to the eccentric load, and weight releasers may not need to be reloaded to induce performance enhancement.


2020 ◽  
Vol 24 (1) ◽  
pp. 19-23
Author(s):  
Juhi K. Bharnuke ◽  
Rajani P. Mullerpatan ◽  
Claire Hiller

Indian classical dance involves a constant change of the base of support from stance to low jumps and spins along with intricate footwork. Graceful movement of the torso, shifting from side to side and turning around the axis of the spine, challenges balance. Yet, balance performance remains unexplored in Indian classical dancers. Therefore, the present study aimed to compare the standing balance of 36 active female dancers (18 to 25 years of age) who had performed Indian classical dance for a minimum of 10 years with 36 healthy age-matched women not involved in regular physical activity. Balance was evaluated in static and dynamic conditions of single and dual-limb stance on a force plate using center-of-pressure trajectory and the Star Excursion Balance Test (SEBT). Dancers demonstrated better balance on both instrumented and non-instrumented outcome variables: wide base of support with eyes open and with eyes closed; for 30-second single limb stance with eyes open and with eyes closed; for 13-second dual task in single limb stance; and for 22-second dual task in wide base of support. The SEBT revealed significantly better balance performance of dancers in the three directions tested: anterior, posteromedial, and posterolateral. There was also a strength component of the study on which the dancers achieved significantly higher scores than controls for the three muscle groups tested (gastrocsoleus, gluteus medius, and quadriceps), which can be attributed to their training. These findings can be used to recommend classical dance training to achieve the dual purpose of deriving better balance and stronger bodies and maintaining the Indian dance heritage.


2006 ◽  
Vol 100 (6) ◽  
pp. 2048-2056 ◽  
Author(s):  
Gladys L. Onambele ◽  
Marco V. Narici ◽  
Constantinos N. Maganaris

We tested the hypothesis that compromised postural balance in older subjects is associated with changes in calf muscle-tendon physiological and mechanical properties. Trial duration and center of pressure (COP) displacements were measured in 24 younger (aged 24 ± 1 yr), 10 middle-aged (aged 46 ± 1 yr), and 36 older (aged 68 ± 1 yr) healthy subjects under varying levels of postural difficulty. Muscle-tendon characteristics were assessed by dynamometry, twitch superimposition, and ultrasonography. In tandem and single-leg stances, trial duration decreased (≤65% lower, P < 0.001) and COP displacements increased (≤90% higher, P < 0.05) with age. Muscle strength, size, activation capacity, and tendon mechanical properties decreased with age by 55, 13, 13, and 36–48%, respectively ( P < 0.05). Regressions with these parameters and balance indexes were significant ( P < 0.05) for single-leg and tandem (0.69 < r2 < 0.90) postures only, indicating that the age-related changes in muscle-tendon characteristics may explain the majority of the variance in balance performance during tasks more difficult than habitual bipedal stance.


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