Cell-Free DNA as an Earlier Predictor of Exercise-Induced Performance Decrement Related to Muscle Damage

2018 ◽  
Vol 13 (7) ◽  
pp. 953-956 ◽  
Author(s):  
Michely V. Andreatta ◽  
Victor M. Curty ◽  
João Victor S. Coutinho ◽  
Miguel Ângelo A. Santos ◽  
Paula F. Vassallo ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Lactate Concentration ◽  
Muscle Performance ◽  
Exercise Session ◽  
Performance Decrement ◽  
Countermovement Jump ◽  
Cell Free Dna ◽  
Jump Performance ◽  
Squat Jump ◽  
Free Dna

Purpose: To evaluate whether cell-free DNA (cfDNA) levels increase immediately after an acute light and heavy resistance exercise (RE) bout and whether cfDNA levels are associated with functional muscle capacity up to 48 h after an exercise session. Methods: Twenty healthy volunteers performed 3 sets of leg-press RE with 80% of 1-repetition maximum (1RM) (RE80) or 40% of 1RM (RE40) with similar exercise volume. Blood lactate was measured after completion of the 3 sets. Creatine kinase, cfDNA, and jump performance were evaluated before (pre) exercise, immediately postexercise (post-0h), and every 24 h until 48 h. Results: Lactate concentration increased similarly in both groups (RE40 4.0 [1.3] mmol/L; RE80 4.8 [1.3] mmol/L). No changes were observed in squat-jump and countermovement-jump performance after RE40; however, both jumps remained reduced until 48 h in the RE80 group. Creatine kinase concentration increased post-24h only in the RE80 group (pre 128.8 [73.7] U/L to post-24h 313.8 [116.4] U/L). cfDNA concentration increased post-0h only in the RE80 group (pre 249.8 [82.3] ng/mL to post-0h 406.3 [67.2] ng/mL). There was a negative correlation between post-0h cfDNA concentration and post-24h squat jump (r = −.521; P = .01) and post-0h cfDNA concentration and post-24h countermovement jump (r = −.539; P = .01). Conclusion: cfDNA increases in response to RE intensity even when not performed until exhaustion. cfDNA measured immediately after RE is a promising biomarker for muscle-performance decrement up to 48 h after a RE bout.

scholarly journals Effects of Short-Term Plyometric Training on Agility, Jump and Repeated Sprint Performance in Female Soccer Players

2021 ◽  
Vol 18 (5) ◽  
pp. 2274
Author(s):  
Marcin Maciejczyk ◽  
Renata Błyszczuk ◽  
Aleksander Drwal ◽  
Beata Nowak ◽  
Marek Strzała
Keyword(s):  
Physical Performance ◽  
Sprint Performance ◽  
Soccer Players ◽  
Plyometric Training ◽  
Countermovement Jump ◽  
Short Term ◽  
Jump Performance ◽  
Squat Jump ◽  
Repeated Sprint ◽  
Before And After

The aim of the study was to determine the effects of short-term (4 weeks, twice a week: 8 sessions) plyometric training on agility, jump, and repeated sprint performance in female soccer players. The study comprised 17 females performing this sports discipline. The players were randomly divided into two groups: with plyometric training (PLY) and the control (CON). All players followed the same training program, but the PLY group also performed plyometric exercises. Tests used to evaluate physical performance were carried out immediately before and after PLY. After implementing the short PLY training, significant improvement in jump performance (squat jump: p = 0.04, ES = 0.48, countermovement jump: p = 0.009, ES = 0.42) and agility (p = 0.003, ES = 0.7) was noted in the PLY group. In the CON group, no significant (p > 0.05) changes in physical performance were observed. In contrast, PLY did not improve repeated sprint performance (p > 0.05) among female soccer players. In our research, it was shown that PLY can also be effective when performed for only 4 weeks instead of the 6–12 weeks typically applied.

scholarly journals Effects of Slackline Training on Acceleration, Agility, Jump Performance and Postural Control in Youth Soccer Players

2019 ◽  
Vol 67 (1) ◽  
pp. 235-245
Author(s):  
Javier Fernández-Rio ◽  
Luis Santos ◽  
Benjamín Fernández-García ◽  
Roberto Robles ◽  
Iván Casquero ◽  
...  
Keyword(s):  
Postural Control ◽  
Training Program ◽  
Perceived Exertion ◽  
Center Of Pressure ◽  
Training Session ◽  
Soccer Players ◽  
Control Group ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Squat Jump

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.

Kinetic and Kinematic Changes in Vertical Jump in Prepubescent Girls After 10 Weeks of Plyometric Training

2020 ◽  
Vol 32 (2) ◽  
pp. 81-88 ◽  
Author(s):  
K. Katsikari ◽  
Eleni Bassa ◽  
Dimitrios Skoufas ◽  
Savvas Lazaridis ◽  
Christos Kotzamanidis ◽  
...  
Keyword(s):  
Contact Time ◽  
Control Group ◽  
Kinetic Properties ◽  
Plyometric Training ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Squat Jump ◽  
Short Contact Time ◽  
Prolonged Contact ◽  
Drop Jumps

Purpose: To examine the effect of a 10-week plyometric training (PT) on the kinematic and kinetic properties of prepubescent girls during squat jump, countermovement jump, and drop jumps. Methods: Twenty-four untrained girls (aged 9–11 y) were assigned to a training group (TG) and a control group. The TG followed twice a week PT for 10 weeks. Squat jump, countermovement jump, and drop jumps performed from heights of 20, 35, and 50 cm were tested before and after PT. Jump height, kinematic, and kinetic parameters were evaluated using a motion analysis system and a force plate. Results: Jumping height in all jump types increased significantly after PT for the TG (P < .001). After training, the TG presented increased power (P < .001) and knee angular velocity (P < .001), higher knee flexion at the deepest point during the braking phase (P < .001), longer contact time (P < .001), and unchanged stiffness and reaction strength index (P > .05). No differences were observed in the control group (P > .05). Conclusion: These findings indicate that a 10-week PT positively affected jumping performance in prepubescent girls who improved their drop jump performance after training not by adopting a stiff/bouncing jumping style of short contact time and increased stiffness, but a compliant/absorbing style of prolonged contact time.

scholarly journals Association Between Match Activity Variables, Measures of Fatigue and Neuromuscular Performance Capacity Following Elite Competitive Soccer Matches

2017 ◽  
Vol 60 (1) ◽  
pp. 93-99 ◽  
Author(s):  
Ian Varley ◽  
Ryan Lewin ◽  
Robert Needham ◽  
Robin T. Thorpe ◽  
Ross Burbeary
Keyword(s):  
Creatine Kinase ◽  
Muscle Soreness ◽  
Soccer Players ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Performance Capacity ◽  
Neuromuscular Performance ◽  
Professional Soccer ◽  
Activity Variables

Abstract The aim of the study was to assess the relationships between match activity variables, subsequent fatigue and neuromuscular performance capacity in elite soccer players. Subjects (n = 10) were professional soccer players participating in the English Championships. Match activity variables and markers of fatigue status were measured before and following two matches. Creatine kinase (CK) and muscle soreness were measured at baseline, immediately following, as well as 40 and 64 h post-match. Countermovement jump performance and perceived ratings of wellness were measured at baseline, then 40 and 64 h post-match. Relationships were shown between CK and the total number of accelerations and decelerations immediately (r = 0.63; large), 40 h (r = 0.45; moderate) and 64 h post-match (r = 0.35; moderate) (p < 0.05). Relationships between CK and total sprint distance (r = 0.39; moderate) and the number of sprints (r = 0.35; moderate) 40 h post-match (p < 0.05) were observed. Furthermore, relationships were shown between the perceived rating of wellness and number of accelerations 40 (r = 0.52; large) and 64 h (r = 0.40; moderate) post-match, sprint distance 40 h post-match (r = 0.40; moderate) and the total number of sprints 40 h post-match (r = 0.51; large) (p < 0.05). The quantification of match activity variables, particularly the total number of accelerations and decelerations and the number of sprints, provides insights into the fatigue status in elite soccer players 40 and 64 h post-match.

scholarly journals Greater volumes are required to reduce muscle performance in well-trained individuals

2018 ◽  
Vol 20 (2) ◽  
pp. 190-200
Author(s):  
Filipe Dinato de Lima ◽  
Amilton Vieira ◽  
Ana Luiza Matias Correia ◽  
Ricardo Moreno Lima ◽  
Andrew Correa da Fonseca ◽  
...  
Keyword(s):  
Muscle Performance ◽  
Rest Interval ◽  
Countermovement Jump ◽  
Training Experience ◽  
Jump Performance ◽  
Trained Subjects ◽  
Great Volume ◽  
Drop Jumps ◽  
Isometric Torque ◽  
Post Assessment

A specific drop jumps (DJs) protocol (using 100 jumps) has been largely used to induce muscle damage. However, it failed to show relevant drop in performance in well-trained individuals. Trained subjects may require a protocol with greater volume to induce decrease of muscle performance. The aim of this study was to assess muscle performance after two DJs damaging protocols with different volumes in well-trained individuals. Eighteen strength and/or power-trained males (4.92 ± 2.78 years of training experience) were randomly assigned into one of two groups: DJ100 (five sets of 20 DJs) or DJ140 (seven sets of 20 DJs), with 2-min of rest interval. DJs were performed from a 60-cm box. After landing, the volunteers performed a maximal vertical rebound jump. Muscle swelling increased significantly on both DJ100 and DJ140 (p < 0.001). Maximal isometric torque (MIT) decreased significantly on both DJ100 (p = 0.005) and DJ140 (p < 0.001). MIT showed no between-group difference on pre-assessment (p = 0.815). However, on post-assessment, MIT was significantly lower on DJ140 than DJ100 (p = 0.043). Countermovement jump (CMJ) decreased significantly on DJ140 (p = 0.001), but not on DJ100 (p = 0.802). There was no between-group difference on pre-assessment (p = 0.978). However, on post-assessment, CMJ was significantly lower on DJ140 than DJ100 (p = 0.038). DJ140 induced greater drop in isometric strength than DJ100 and only DJ140 significantly reduced jump performance. These results demonstrated that well-trained individuals require a great volume of DJs to reduce substantially muscle performance.

Serum myoglobin, creatine kinase, and cell-free DNA in endurance sled dogs and sled dogs with clinical rhabdomyolysis

2018 ◽  
Vol 28 (4) ◽  
pp. 310-316 ◽  
Author(s):  
Veronica C. Devall ◽  
Robert Goggs ◽  
Christina Hansen ◽  
Christopher W. Frye ◽  
Jo-Annie Letendre ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Cell Free Dna ◽  
Free Dna ◽  
Sled Dogs ◽  
Serum Myoglobin

scholarly journals Relationship between body composition, Yo-Yo intermittent recovery test and vertical jump test in elite young soccer players

2021 ◽  
Author(s):  
Erkan Akdoğan ◽  
Süleyman Olgun
Keyword(s):  
Body Composition ◽  
Pearson Correlation ◽  
Vertical Jump ◽  
Soccer Players ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Squat Jump ◽  
Recovery Test ◽  
Jump Test ◽  
Regional Body Composition

Objective: The aim of this study is to find out the relationships among body composition, Yo-Yo intermittent recovery (IR) test and vertical jump test in elite young soccer players. Material and Methods: Eighteen healthy young male soccer players (Age: 16.5±0.3 years, height: 178.0±5.9 cm, body weight: 65.9±7.9kg,) voluntarily participated in the study. Total and regional body composition parameters of the soccer players were examined through a dual-energy x-ray absorptiometry (DEXA) method. Vertical jump performance tests were squat jump (SJ) and active jump (AJ), and endurance performances were determined by the Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1). Relationships among body composition, Yo-Yo intermittent recovery test and vertical jump test were analyzed with Pearson Correlation coefficient. Significance level was taken as ≤0.05. Results: A statistically significant negative correlation was found between squat jump and countermovement jump (r=-0.588, r=-0.573, p<0.05), and the leg fat rate. However, there were no statistically significant relationship among squat jump, Yo-Yo IR1 and countermovement jump and other whole/regional body composition (p>0.05). Conclusion: Changes in body composition are important issues for the physical performance level of young soccer players, as local excess body fat may cause deterioration, especially in jumping performance.

Plyometric Training in Normobaric Hypoxia improves Jump Performance

2021 ◽  
Author(s):  
Betül Coşkun ◽  
Dicle Aras ◽  
Cengiz Akalan ◽  
Settar Kocak ◽  
Michael J. Hamlin
Keyword(s):  
Sprint Performance ◽  
Normobaric Hypoxia ◽  
Control Group ◽  
Drop Jump ◽  
Plyometric Training ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Squat Jump ◽  
Hypoxic Conditions ◽  
And Function

AbstractStrength training in hypoxia has been shown to enhance hypertrophy and function of skeletal muscle, however, the effects of plyometric training in hypoxia is relatively unknown. Therefore, this study aimed to examine the effects of plyometric training in hypoxia compared to normoxia on body composition, sprint and jump parameters. Twenty-three male physical education students (20.4±2.0 years, mean±SD) participated in the study and were divided into a plyometric training in hypoxia (PTH, n=8), plyometric training in normoxia (PTN, n=7) or control group (C, n=8). The PTH group trained in normobaric hypoxia (approximately 3536 m) 3 days/week for 8 weeks, while the PTN trained in normoxia. PTH induced significant improvements from baseline to post-testing in countermovement-jump (37.8±6.7 cm, 43.4±5.0 cm, p<0.05), squat-jump (35.4±6.2 cm, 41.1±5.7 cm, p<0.05), drop-jump height (32.8±6 cm, 38.1±6 cm, p<0.05) and 20-m sprint performance (3257.1±109.5 ms, 3145.8±83.6 ms, p<0.05); whereas PTN produced significant improvement only in countermovement-jump (37.3±4.8 cm, 40.5±4.5 cm, p<0.05) and 20-m sprint performance (3209.3±76.1 ms, 3126.6±100.4 ms, p<0.05). Plyometric training under hypoxic conditions induces greater improvement in some jump measures (drop-jump and squat-jump) compared to similar training in normoxia.

scholarly journals Effects of Two Contrast Training Programs on Jump Performance in Rugby Union Players During a Competition Phase

2012 ◽  
Vol 7 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Christos K. Argus ◽  
Nicholas D. Gill ◽  
Justin W.L. Keogh ◽  
Michael R. McGuigan ◽  
Will G. Hopkins
Keyword(s):  
Training Programs ◽  
Training Group ◽  
Rugby Union ◽  
Power Training ◽  
Strength Index ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Squat Jump ◽  
Volume Load ◽  
High Level

Purpose:There is little literature comparing contrast training programs typically performed by team-sport athletes within a competitive phase. We compared the effects of two contrast training programs on a range of measures in high-level rugby union players during the competition season.Methods:The programs consisted of a higher volume-load (strength-power) or lower volume-load (speed-power) resistance training; each included a tapering of loading (higher force early in the week, higher velocity later in the week) and was performed twice a week for 4 wk. Eighteen players were assessed for peak power during a bodyweight countermovement jump (BWCMJ), bodyweight squat jump (BWSJ), 50 kg countermovement jump (50CMJ), 50 kg squat jump (50SJ), broad jump (BJ), and reactive strength index (RSI; jump height divided by contact time during a depth jump). Players were then randomized to either training group and were reassessed following the intervention. Inferences were based on uncertainty in outcomes relative to thresholds for standardized changes.Results:There were small between-group differences in favor of strength-power training for mean changes in the 50CMJ (8%; 90% confidence limits, ±8%), 50SJ (8%; ±10%), and BJ (2%; ±3%). Differences between groups for BWCMJ, BWSJ, and reactive strength index were unclear. For most measures there were smaller individual differences in changes with strength-power training.Conclusion:Our findings suggest that high-level rugby union athletes should be exposed to higher volume-load contrast training which includes one heavy lifting session each week for larger and more uniform adaptation to occur in explosive power throughout a competitive phase of the season.

scholarly journals The Magical Horizontal Force Muscle? A Preliminary Study Examining the “Force-Vector” Theory

Sports ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 30 ◽  
Author(s):  
David Fitzpatrick ◽  
Giuseppe Cimadoro ◽  
Daniel Cleather
Keyword(s):  
Female Athletes ◽  
Coordinate Frame ◽  
Horizontal Force ◽  
Countermovement Jump ◽  
Force Vector ◽  
Jump Performance ◽  
Squat Jump ◽  
Repetition Maximum ◽  
Vector Theory ◽  
Sports Skills

The force-vector theory contends that horizontal exercises are more specific to horizontal sports skills. In this context, the focus is on horizontal force production relative to the global coordinate frame. However, according to the principle of dynamic correspondence, the direction of force relative to the athlete is more important, and thus the basis for the force-vector theory is flawed. The purpose of this study was therefore to test the force-vector theory. According to the force-vector theory, hip thrust is a horizontally loaded exercise, and so hip thrust training would be expected to create greater improvements in horizontal jump performance than vertical jump performance. Eleven collegiate female athletes aged 18–24 years completed a 14-week hip thrust training programme. Pre and post testing was used to measure the following: vertical squat jump, vertical countermovement jump, horizontal squat jump, horizontal countermovement jump and hip thrust 3 repetition maximum (3RM). Subjects improved their 3 repetition maximum hip thrust performance by 33.0% (d = 1.399, p < 0.001, η2 = 0.784) and their vertical and horizontal jump performance (improvements ranged from 5.4–7.7%; d = 0.371–0.477, p = 0.004, η2 = 0.585). However, there were no differences in the magnitude of the improvement between horizontal and vertical jumping (p = 0.561, η2 = 0.035). The results of this study are contrary to the predictions of the force-vector theory. Furthermore, this paper concludes with an analysis of the force-vector theory, presenting the mechanical inconsistencies in the theory. Coaches should use the well established principle of dynamic correspondence in order to assess the mechanical similarity of exercises to sports skills.

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