scholarly journals Yo-Yo Intermittent Recovery Level 2 Test Performance and Leg Muscle Growth in a Six-month Period among Pubescent Soccer Players at Different Stages of Maturity

2011 ◽  
Vol 9 ◽  
pp. 105-112
Author(s):  
Kentaro Chuman ◽  
Yoshihiro Hoshikawa ◽  
Tomomi Iida ◽  
Takahiko Nishijima
Keyword(s):  
Test Performance ◽  
Muscle Growth ◽  
Soccer Players ◽  
Leg Muscle ◽  
Level 2

Effect of 2-wk intensified training and inactivity on muscle Na+-K+ pump expression, phospholemman (FXYD1) phosphorylation, and performance in soccer players

2010 ◽  
Vol 108 (4) ◽  
pp. 898-905 ◽  
Author(s):  
Martin Thomassen ◽  
Peter M. Christensen ◽  
Thomas P. Gunnarsson ◽  
Lars Nybo ◽  
Jens Bangsbo
Keyword(s):  
Test Performance ◽  
Soccer Players ◽  
Intervention Period ◽  
Short Term ◽  
High Intensity Training ◽  
Muscle Adaptations ◽  
Isoform Expression ◽  
And Performance ◽  
Level 2 ◽  
Intensity Training

The present study examined muscle adaptations and alterations in performance of highly trained soccer players with intensified training or training cessation. Eighteen elite soccer players were, for a 2-wk period, assigned to either a group that performed high-intensity training with a reduction in the amount of training (HI, n = 7), or an inactivity group without training (IN, n = 11). HI improved ( P < 0.05) performance of the 4th, 6th, and 10th sprint in a repeated 20-m sprint test, and IN reduced ( P < 0.05) performance in the 5th to the 10th sprints after the 2-wk intervention period. In addition, the Yo-Yo intermittent recovery level 2 test performance of IN was lowered from 845 ± 48 to 654 ± 30 m. In HI, the protein expression of the Na+-K+ pump α2-isoform was 15% higher ( P < 0.05) after the intervention period, whereas no changes were observed in α1- and β1-isoform expression. In IN, Na+-K+ pump expression was not changed. In HI, the FXYD1ser68-to-FXYD1 ratio was 27% higher ( P < 0.01) after the intervention period, and, in IN, the AB_FXYD1ser68 signal was 18% lower ( P < 0.05) after inactivity. The change in FXYD1ser68-to-FXYD1 ratio was correlated ( r2 = 0.35; P < 0.05) with change in performance in repeated sprint test. The present data suggest that short-term intensified training, even for trained soccer players, can increase muscle Na+-K+ pump α2-isoform expression, and that cessation of training for 2 wk does not affect the expression of Na+-K+ pump isoforms. Resting phosphorylation status of the Na+-K+ pump is changed by training and inactivity and may play a role in performance during repeated, intense exercise.

Myostatin expression in porcine tissues: tissue specificity and developmental and postnatal regulation

1998 ◽  
Vol 275 (4) ◽  
pp. R1265-R1273 ◽  
Author(s):  
Shaoquan Ji ◽  
R. L. Losinski ◽  
S. G. Cornelius ◽  
G. R. Frank ◽  
G. M. Willis ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mammary Gland ◽  
Birth Weight ◽  
Low Birth Weight ◽  
Tissue Specificity ◽  
Muscle Growth ◽  
Mrna Abundance ◽  
Longissimus Muscle ◽  
Gland Development ◽  
Level 2

The objective of this study was to establish the developmental pattern and tissue specificity of porcine myostatin expression and to evaluate expression in skeletal muscle during circumstances in which muscle growth was altered. Northern blot analysis revealed two transcripts (1.5 and 0.8 kb). Myostatin mRNA was detected in whole fetuses at 21 and 35 days and was markedly increased ( P < 0.05) by 49 days. At birth, mRNA abundance in longissimus muscle had declined significantly ( P < 0.05) from that at day 105 of gestation and continued to decrease ( P < 0.05) to its lowest level 2 wk postnatally (4 kg body wt). Myostatin expression was higher ( P < 0.05) at 55, 107, and 162 kg body wt than at 4 kg body wt. Postnatally, myostatin mRNA was detected in skeletal muscle and mammary gland. Expression at birth was 65% higher ( P < 0.04) in longissimus muscle of low-birth-weight piglets (0.57 ± 0.052 kg body wt) vs. normal (1.37 ± 0.077 kg body wt) littermates, irrespective of gender. However, suppression of longissimus muscle growth by food deprivation (3 days) did not alter ( P > 0.15) myostatin expression in either 4- or 7-wk-old piglets. Additionally, myostatin mRNA abundance was not changed by porcine growth hormone administration in growing animals. These data indicate that myostatin expression in skeletal muscle peaks prenatally and that greater expression is associated with low birth weight. Expression in mammary gland indicates a possible role for myostatin in mammary gland development and/or lactation.

Reliability and Construct Validity of Yo-Yo Tests in Untrained and Soccer-Trained Schoolgirls Aged 9–16

2016 ◽  
Vol 28 (2) ◽  
pp. 321-330 ◽  
Author(s):  
Susana C. A. Póvoas ◽  
Carlo Castagna ◽  
José Manuel da Costa Soares ◽  
Pedro Silva ◽  
Manuel Coelho-e-Silva ◽  
...  
Keyword(s):  
Heart Rate ◽  
Construct Validity ◽  
Coefficient Of Variation ◽  
Intermittent Exercise ◽  
Intraclass Correlation ◽  
Soccer Players ◽  
Confidence Limits ◽  
Peak Heart Rate ◽  
Level 1 ◽  
Level 2

Purpose:The reliability and construct validity of three age-adapted-intensity Yo-Yo tests were evaluated in untrained (n = 67) vs. soccer-trained (n = 65) 9- to 16-year-old schoolgirls.Methods:Tests were performed 7 days apart for reliability (9- to 11-year-old: Yo-Yo intermittent recovery level 1 children’s test; 12- to 13-yearold: Yo-Yo intermittent endurance level 1; and 14- to 16-year-old: Yo-Yo intermittent endurance level 2).Results:Yo-Yo distance covered was 40% (776 ± 324 vs. 556 ± 156 m), 85% (1252 ± 484 vs. 675 ± 252 m) and 138% (674 ± 336 vs. 283 ± 66 m) greater (p ≤ .010) for the soccer-trained than for the untrained girls aged 9–11, 12–13 and 14–16 years, respectively. Typical errors of measurement for Yo-Yo distance covered, expressed as a percentage of the coefficient of variation (confidence limits), were 10.1% (8.1–13.7%), 11.0% (8.6–15.4%) and 11.6% (9.2–16.1%) for soccer players, and 11.5% (9.1–15.8%), 14.1% (11.0–19.8%) and 10.6% (8.5–14.2%) for untrained girls, aged 9–11, 12–13 and 14–16, respectively. Intraclass correlation coefficient values for test-retest were excellent (0.795–0.973) in both groups. No significant differences were observed in relative exercise peak heart rate (%HRpeak) between groups during test and retest.Conclusion:The Yo-Yo tests are reliable for determining intermittent-exercise capacity and %HRpeak for soccer players and untrained 9- to 16-year-old girls. They also possess construct validity with better performances for soccer players compared with untrained age-matched girls, despite similar %HRpeak.

Relationship of Training Load with High-intensity Running in Professional Soccer Players

2019 ◽  
Vol 40 (05) ◽  
pp. 336-343 ◽  
Author(s):  
Marcus Lee ◽  
Swarup Mukherjee
Keyword(s):  
High Intensity ◽  
Training Load ◽  
Soccer Players ◽  
Moderate Intensity ◽  
Professional Soccer ◽  
Repeated Sprint ◽  
Relationship Of ◽  
The Relationship ◽  
Test Level ◽  
Level 2

AbstractThis study determined the training load (TL) and its relationship with high-intensity running performance across the season in professional soccer players. The TL, YoYo Intermittent Recovery Test Level 2 (YYIR 2) and repeated sprint ability (RSA) were monitored in 29 players (age 26.2±3.8 years, height 173.6±5.6 cm, body mass 68.5±8.6 kg). In the mid in-season (MS), Lucia TRIMP (TRIMPL) was inversely correlated with YYIR 2 (r=−0.6, p<0.05), with total distance (TD), work-rate (WR), low-intensity distance (LID) and player load (PL) showing correlation with YYIR 2 (r=0.81, 0.77, 0.88, 0.67; p<0.05) in the late in-season (LS). In pre-season (PS), TD, WR and moderate-intensity distance (MID) were correlated with YYIR 2 (r=0.65, 0.80, 0.83, p<0.05), whereas in early in-season (ES), TD, WR, LID were correlated with YYIR 2 performance (r=0.58, 0.67, 0.55, p<0.05). There was no significant relationship (p>0.05) between TL and RSA. The findings showed the volume, intensity and types of TL accrued influences the relationship with physical performance that suggest the significance of phase-specific monitoring of TL for maximizing performance in soccer players.

Effects of a 20-min Nap after Sleep Deprivation on Brain Activity and Soccer Performance

2020 ◽  
Vol 41 (14) ◽  
pp. 1009-1016
Author(s):  
Amornpan Ajjimaporn ◽  
Papatsorn Ramyarangsi ◽  
Vorasith Siripornpanich
Keyword(s):  
Sleep Deprivation ◽  
Perceived Exertion ◽  
Brain Activity ◽  
Rating Of Perceived Exertion ◽  
Soccer Players ◽  
Mean Power ◽  
Auditory Reaction Time ◽  
Normal Sleep ◽  
The Mean ◽  
Leg Muscle

AbstractWe examined effects of a 20-min nap following 3 h of sleep deprivation on brain wave activity, auditory reaction time, the running-based anaerobic sprint test, leg muscle strength and the rating of perceived exertion in male college soccer players. Eleven players underwent three sleep conditions; normal sleep, sleep deprivation and 20-min nap after sleep deprivation. The sleep deprivation demonstrated an increase in the mean power of delta waves over the frontal area and a decrease in the mean power of alpha waves over the parietal area compared to the normal sleep. The nap and the sleep deprivation showed an increase in auditory reaction time compared with those in the normal sleep. The sleep deprivation demonstrated a decrease in the running-based anaerobic sprint test compared to the normal sleep, whereas the nap has partially reversed only minimal power and average power of the running-based anaerobic sprint test. The nap showed a recovery effect on leg muscle strength, but not on the rating of perceived exertion compared with the sleep deprivation. Thus, a 20-min nap after sleep deprivation did not completely return brain activity back to active state and did not entirely reverse the negative impact of sleep deprivation on soccer performance in soccer players.

scholarly journals Discriminative validity of the lower and upper quarter Y balance test performance: a comparison between healthy trained and untrained youth

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Gerrit Schwiertz ◽  
Rainer Beurskens ◽  
Thomas Muehlbauer
Keyword(s):  
Test Performance ◽  
Dynamic Balance ◽  
Characteristic Curve ◽  
Area Under The Curve ◽  
Receiver Operator Characteristic Curve ◽  
Soccer Players ◽  
Balance Test ◽  
Discriminative Validity ◽  
Youth Athletes ◽  
Male Subjects

Abstract Background The Lower (YBT-LQ) and Upper (YBT-UQ) Quarter Y Balance Test have been widely used for the assessment of dynamic balance and shoulder mobility/stability, respectively. However, investigations on the validity of the two tests in youth are lacking. Therefore, we performed two studies to determine discriminative validity of the YBT-LQ (study 1) and the YBT-UQ (study 2) in healthy youth. Methods Sixty-nine male soccer players (age: 14.4 ± 1.9 yrs) and 69 age-matched untrained male subjects (14.3 ± 1.6 yrs) participated in study 1 and 37 young swimmers (age: 12.3 ± 2.1 yrs) as well as 37 age−/sex-matched individuals (age: 12.5 ± 2.0 yrs) took part in study 2. Absolute (cm) and relative (% leg/arm length) maximal reach distances per reach direction and the composite score of the YBT-LQ/UQ were used as outcome measures. One-way analysis of variance and the receiver operator characteristic curve analysis (i.e., calculating the area under the curve [AUC]) were conducted to assess discriminative validity. Results Concerning the relative values, youth athletes showed significantly better YBT-LQ (study 1: p < 0.001, d = 0.86–1.21) and YBT-UQ (study 2: p < 0.001, d = 0.88–1.48) test performances compared to age- and sex-matched untrained subjects. Further, AUC-values indicated a chance of ≥74% (YBT-LQ) and ≥ 71% (YBT-UQ) to discriminate between youth athletes and controls. These findings were confirmed when using the absolute data for analysis. Conclusions According to our results, the YBT-LQ and the YBT-UQ seem to be useful test instruments to discriminate trained and untrained healthy youth performance for dynamic balance and shoulder mobility/stability, respectively.

scholarly journals Comparison between two types of anaerobic speed endurance training in competitive soccer players

2016 ◽  
Vol 51 (1) ◽  
pp. 183-192 ◽  
Author(s):  
Magni Mohr ◽  
Peter Krustrup
Keyword(s):  
Randomised Controlled Trial ◽  
Controlled Trial ◽  
Soccer Players ◽  
Fatigue Index ◽  
Post Intervention ◽  
Average Speed ◽  
Repeated Sprint ◽  
Competitive Season ◽  
Randomised Controlled ◽  
Level 2

Abstract The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players. In a randomised controlled trial 18 male sub-elite players were exposed to additional speed endurance production (SEP) or speed endurance maintenance (SEM) training (two additional sessions/wk for 4 weeks) during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2) and a repeated sprint test (RST) pre- and post-intervention. Yo-Yo IR2 performance increased (p<0.001) by 50 ± 8% and 26 ± 5% in SEP and SEM, respectively, with greater (p=0.03) improvement in SEP. RST performance improved by 2.1 ± 0.3% and 1.3 ± 0.4% in SEP and SEM, respectively, while the RST fatigue index decreased (4.4 ± 0.8 to 3.4 ± 0.5%; p<0.04) in SEP only. Peak and average speed during training were higher (p<0.001) in SEP than in SEM (24.5 ± 0.3 vs 19.2 ± 0.3 and 15.5 ± 0.1 km·h-1 vs 9.4 ± 0.1 km·h-1). Additional in-season anaerobic speed endurance production and maintenance training improves high-intensity exercise performance in competitive soccer players with superior effects of speed endurance production training.

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