The influence of external load variables on creatine kinase change during preseason training period

Abstract Objective The aim of the present study was to analyse the relationships between creatine kinase (CK) concentration, an indirect marker of muscle damage, and global positioning system (GPS)-derived metrics of a continuous two-week-long preseason training period in elite football. Design Twenty-one elite male professional soccer players were assessed during a 14-day preseason preparatory period. CK concentrations were determined each morning, and a GPS system was used to quantify the external load. A generalized estimating equation (GEE) model was established to determine the extent to which the external load parameter explained post-training CK levels. Results The GEE model found that higher numbers of decelerations (χ 2 = 7.83, P = 0.005) were most strongly associated with the post-training CK level. Decelerations and accelerations accounted for 62% and 11% of the post-training CK level, respectively, and considerable interindividual variability existed in the data. Conclusion The use of GPS to predict muscle damage could be of use to coaches and practitioners in prescribing recovery practices. Based on GPS data, more individualized strategies could be devised and could potentially result in better subsequent performance.

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High coenzyme Q10 plasma levels improve stress and damage markers in professional soccer players during competition

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000659 ◽

2020 ◽

pp. 1-12

Author(s):

Ana Sánchez-Cuesta ◽

Ana Belén Cortés-Rodríguez ◽

Ignacio Navas-Enamorado ◽

José Antonio Lekue ◽

Toscana Viar ◽

...

Keyword(s):

Creatine Kinase ◽

Muscle Damage ◽

Kidney Function ◽

Coenzyme Q ◽

Muscle Performance ◽

Soccer Players ◽

Reduced Form ◽

Plasma Parameters ◽

Professional Soccer ◽

Key Factor

Abstract. Ubiquinol, the reduced form of Coenzyme Q10 (CoQ10), is a key factor in bioenergetics and antioxidant protection. During competition, professional soccer players suffer from considerable physical stress causing high risk of muscle damage. For athletes, supplementation with several antioxidants, including CoQ10, is widely recommended to avoid oxidative stress and muscle damage. We performed an observational study of plasma parameters associated with CoQ10 levels in professional soccer players of the Spanish First League team Athletic Club de Bilbao over two consecutive seasons (n = 24–25) in order determine their relationship with damage, stress and performance during competition. We analyzed three different moments of the competition: preterm, initial phase and mid phase. Metabolites and factors related with stress (testosterone/cortisol) and muscle damage (creatine kinase) were determined. Physical activity during matches was analyzed over the 2015/16 season in those players participating in complete matches. In the mid phase of competition, CoQ10 levels were higher in 2015/16 (906.8 ± 307.9 vs. 584.3 ± 196.3 pmol/mL, p = 0.0006) High levels of CoQ10 in the hardest phase of competition were associated with a reduction in the levels of the muscle-damage marker creatine kinase (Pearsons’ correlation coefficient (r) = − 0.460, p = 0.00168) and a trend for the stress marker cortisol (r = −0.252, p = 0.150). Plasma ubiquinol was also associated with better kidney function (r = −0.287, p = 0.0443 for uric acid). Furthermore, high CoQ10 levels were associated with higher muscle performance during matches. Our results suggest that high levels of plasma CoQ10 can prevent muscle damage, improve kidney function and are associated with higher performance in professional soccer players during competition.

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Training/Match External Load Ratios in Professional Soccer Players: A Full-Season Study

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16173057 ◽

2019 ◽

Vol 16 (17) ◽

pp. 3057 ◽

Cited By ~ 5

Author(s):

Filipe Manuel Clemente ◽

Alireza Rabbani ◽

Daniele Conte ◽

Daniel Castillo ◽

José Afonso ◽

...

Keyword(s):

External Load ◽

High Speed ◽

Soccer Players ◽

Professional Soccer ◽

Weekly Training ◽

Global Positioning ◽

Different Types ◽

Mean Differences ◽

The Relationship ◽

Individual Training

The aim of this study was two-fold: (i) to describe the training/match ratios of different external load measures during a full professional soccer season while analyzing the variations between different types of weeks (three, four and five training sessions/week) and (ii) to investigate the relationship between weekly accumulated training loads and the match demands of the same week. Twenty-seven professional soccer players (24.9 ± 3.5 years old) were monitored daily using a 10-Hz global positioning system with a 100-Hz accelerometer. Total distance (TD), running distance (RD), high-speed running (HSR), sprinting distance (SD), player load (PL), number of high accelerations (ACC), and number of high decelerations (DEC) were recorded during training sessions and matches. An individual training/match ratio (TMr) was calculated for each external load measure. Weeks with five training sessions (5dW) presented meaningfully greater TMr than weeks with four (4dW) or three (3dW) training sessions. Additionally, TDratio (TDr) was significantly greater in 5dW than in 3dW (mean differences dif: 1.23 arbitray units A.U.) and 4dW (dif: 0.80 A.U.); HSRr was significantly greater in 5dW than in 3dW (dif: 0.90 A.U.) and 4dW (dif: 0.68 A.U.); and SDr was significantly greater in 5dW than in 3dW (dif: 0.77 A.U.) and 4dW (dif: 0.90 A.U.). Correlations between the weekly training loads and the match demands of the same week were small for PL (r = 0.250 [0.13;0.36]), ACC (r = 0.292 [0.17;0.40]) and DEC (r = 0.236 [0.11;0.35]). This study reveals that ratios of above 1 were observed for specific measures (e.g., HSR, SD). It was also observed that training sessions are not adjusted according to weekly variations in match demands.

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145 President Oral Presentation Pick: Prenatal stress increases skeletal muscle mitochondrial volume density and function in yearling Brahman calves

Journal of Animal Science ◽

10.1093/jas/skaa278.219 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 120-121

Author(s):

Chloey P Guy ◽

Catherine L Wellman ◽

David G Riley ◽

Charles R Long ◽

Ron D Randel ◽

...

Keyword(s):

Oxidative Stress ◽

Creatine Kinase ◽

Muscle Damage ◽

Prenatal Stress ◽

Citrate Synthase ◽

Volume Density ◽

Assembly Factor ◽

Mitochondrial Volume ◽

Mitochondrial Volume Density ◽

And Function

Abstract We previously determined that prenatal stress (PNS) differentially affected methylation of DNA from leukocytes of 28-d-old calves. Specifically, COX14 (cytochrome c oxidase (COX) assembly factor) and CKMT1B (mitochondrial creatine kinase U-type) were hypomethylated and COA5 (COX assembly factor 5), COX5A (COX subunit 5A), NRF1 (nuclear respiratory factor 1), and GSST1 (glutathione S-transferase theta-1) were hypermethylated in PNS compared to non-PNS calves (P ≤ 0.05). Our current objective was to test the hypothesis that PNS exhibit impaired mitochondrial function and greater oxidative stress than non-PNS calves. Blood and longissimus dorsi muscle samples were collected from yearling Brahman calves whose mothers were stressed by 2 h transportation at 60, 80, 100, 120, and 140 days of gestation (PNS; 8 bulls, 6 heifers) and non-PNS calves (4 bulls, 6 heifers). Serum was evaluated for the stress hormone, cortisol, and muscle damage marker, creatine kinase; muscle was analyzed for mitochondrial volume density and function by citrate synthase (CS) and COX activities, respectively, concentration of malondialdehyde, a lipid peroxidation marker, and activity of the antioxidant, superoxide dismutase (SOD). Data were analyzed using mixed linear models with treatment and sex as fixed effects. Serum cortisol was numerically higher in PNS than non-PNS calves but was not statistically different. Muscle CS and COX activities relative to protein were greater in PNS than non-PNS calves (P ≤ 0.03), but COX relative to CS activity was similar between groups. Activity of COX was greater in bulls than heifers (P = 0.03), but no other measure was affected by sex. All other measures were unaffected by PNS. Prenatal stress did not affect markers of muscle damage and oxidative stress in yearling Brahman calves at rest but mitochondrial volume density and function were greater in PNS calves. Acute stressors induce oxidative stress, so implications of differences in mitochondria in PNS calves following a stressor should be investigated.

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Internal and External Training Load in Under-19 versus Professional Soccer Players during the In-Season Period

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18020558 ◽

2021 ◽

Vol 18 (2) ◽

pp. 558

Author(s):

Sullivan Coppalle ◽

Guillaume Ravé ◽

Jason Moran ◽

Iyed Salhi ◽

Abderraouf Ben Abderrahman ◽

...

Keyword(s):

Perceived Exertion ◽

Training Session ◽

Training Load ◽

Rating Of Perceived Exertion ◽

Soccer Players ◽

Time Intervals ◽

Professional Soccer ◽

Global Positioning ◽

External Training ◽

Soccer Team

This study aimed to compare the training load of a professional under-19 soccer team (U-19) to that of an elite adult team (EAT), from the same club, during the in-season period. Thirty-nine healthy soccer players were involved (EAT [n = 20]; U-19 [n = 19]) in the study which spanned four weeks. Training load (TL) was monitored as external TL, using a global positioning system (GPS), and internal TL, using a rating of perceived exertion (RPE). TL data were recorded after each training session. During soccer matches, players’ RPEs were recorded. The internal TL was quantified daily by means of the session rating of perceived exertion (session-RPE) using Borg’s 0–10 scale. For GPS data, the selected running speed intensities (over 0.5 s time intervals) were 12–15.9 km/h; 16–19.9 km/h; 20–24.9 km/h; >25 km/h (sprint). Distances covered between 16 and 19.9 km/h, > 20 km/h and >25 km/h were significantly higher in U-19 compared to EAT over the course of the study (p =0.023, d = 0.243, small; p = 0.016, d = 0.298, small; and p = 0.001, d = 0.564, small, respectively). EAT players performed significantly fewer sprints per week compared to U-19 players (p = 0.002, d = 0.526, small). RPE was significantly higher in U-19 compared to EAT (p =0.001, d = 0.188, trivial). The external and internal measures of TL were significantly higher in the U-19 group compared to the EAT soccer players. In conclusion, the results obtained show that the training load is greater in U19 compared to EAT.

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Variations of Accelerometer and Metabolic Power Global Positioning System Variables across a Soccer Season: A Within-Group Study for Starters and Non-Starters

Applied Sciences ◽

10.3390/app11156747 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6747

Author(s):

Hadi Nobari ◽

Rafael Oliveira ◽

Marefat Siahkouhian ◽

Jorge Pérez-Gómez ◽

Florin Cazan ◽

...

Keyword(s):

Global Positioning System ◽

Soccer Players ◽

Positioning System ◽

Metabolic Power ◽

Early Season ◽

Professional Soccer ◽

Global Positioning ◽

Lower Load ◽

System Variables ◽

In The Beginning

The aims of this study were to analyze the within-group weekly metabolic power average (wMPA), weekly acceleration zones (wAcZ), and weekly deceleration zones (wDcZ), in starter and non-starter professional soccer players, based on different periods of the full season (pre-, early-, mid-, and end-season). Twenty-one professional soccer players (age, 28.3 ± 3.8 years; height, 181.2 ± 7.1 cm; body mass, 74.5 ± 7.7 kg; BMI, 22.6 ± 1.0 kg·m2) were monitored during the full season in the highest level of the Iranian Premier League. WMPA, wAcZ, and wDcZ at three different zones (wAcZ1, wAcZ2, wAcZ3, wDcZ1, wDcZ2, wDcZ3) were collected using Global Positioning System. ANOVA was applied to analyze within-group changes across the different periods of the full season. In general, starters presented higher values in the beginning of the season (pre- and early-season) and lower values at mid- and end-season. Specifically, starters showed significant differences in early- vs. mid-season for wMPA, wAcZ1, and wDcZ1 (p < 0.05), plus early- vs. end-season for wMPA and wAcZ1 (p < 0.01). In addition, non-starters showed higher values in the pre-season that decreased until the end-season for wMPA, wAcZ1, and wDcZ1. Regarding wAcZ2, wDcZ2, wAcZ3, and wDcZ3, non-starters presented higher values in early-season that decreased until the end-season. Specifically, non-starters showed significant differences in pre- vs. mid-season for wMPA, wAcZ1, and wDcZ1; pre- vs. end-season for wMPA, wDcZ1, wDccZ2, and wDcZ3; early- vs. mid-season for wMPA, wAcZ1, wDcZ1, wAcZ2, and wDccZ2; early- vs. end-season for wMPA, wAcZ1, wDcZ1, wAcZ2 wDccZ2, wAcZ3, and wDcZ3; and mid- vs. end-season for wMPA, wAcZ1, and wAcZ3 (p < 0.05). In conclusion, starters were revealed to have higher values in pre- and early-season, and lower values in mid- to end-season, while non-starters were revealed to have lower load values in pre- and end-season and higher load values in early- and mid-season. This study provides extra insights over the season for starters and non-starters, respectively. Data can be used by coaches to better training periodization across soccer season.

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Comparison between Continuous and Fractionated Game Format on Internal and External Load in Small-Sided Games in Soccer

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17020405 ◽

2020 ◽

Vol 17 (2) ◽

pp. 405 ◽

Cited By ~ 1

Author(s):

Luís Branquinho ◽

Ricardo Ferraz ◽

Bruno Travassos ◽

Mário C. Marques

Keyword(s):

Confidence Intervals ◽

External Load ◽

Continuous Method ◽

Soccer Players ◽

Professional Soccer ◽

Game Format ◽

Physical Impact ◽

Mean Differences ◽

External Loads

This study aimed to identify the effects of continuous and fractionated game formats on internal and external load in small-sided games in soccer. Twenty male professional soccer players participated in the study performing the same exercise (5 vs. 5 players) continuously (1 × 24 min) and in a repeated/fractioned manner (2 × 12 min, 4 × 6 min, and 6 × 4 min). A comparison between playing conditions was assessed by means of standardized mean differences calculated with combined variance and respective confidence intervals of 90%. The limits for the statistics were 0.2, trivial; 0.6, small; 1.2, moderate; 2.0, large; and >2.0, very large. The results indicate that the use of the continuous method seems to present the tendency of less physical impact on the internal and external loads compared to the fractionated method. In addition, the higher number of exercise repetitions in the fractionated method was found to increase the external load compared to the continuous method. This study showed that application of small-sided games by the fractionated method tends to result in higher training loads.

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Effect of an intensified training period on well-being indices, recovery and psychological aspects in professional soccer players

Revue Européenne de Psychologie Appliquée ◽

10.1016/j.erap.2020.100603 ◽

2020 ◽

Vol 70 (6) ◽

pp. 100603 ◽

Cited By ~ 1

Author(s):

O. Selmi ◽

I. Ouergui ◽

J. Castellano ◽

D. Levitt ◽

A. Bouassida

Keyword(s):

Well Being ◽

Psychological Aspects ◽

Soccer Players ◽

Training Period ◽

Professional Soccer

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Modifications in the Concentrations of Circulating Myoglobin after Treatment with Low Doses of Adriamycin

Tumori Journal ◽

10.1177/030089168507100509 ◽

1985 ◽

Vol 71 (5) ◽

pp. 463-468 ◽

Cited By ~ 1

Author(s):

Giovanni Carulli ◽

Aldo Clerico ◽

Alessandra Marini ◽

Maria Grazia Del Chicca ◽

Renato Vanacore ◽

...

Keyword(s):

Skeletal Muscle ◽

Creatine Kinase ◽

Cancer Patients ◽

Muscle Damage ◽

Low Doses ◽

Skeletal Muscle Damage ◽

Creatine Kinase Mb

The modifications in the concentration of circulating myoglobin have been studied by means of a radioimmunoassay in 15 cancer patients undergoing polychemotherapy including adriamycin. In 8 patients significant increases in myoglobin levels were found after injection of low doses of the drug (25-50 mg/m2). Moreover, a disturbance of the normal biorhythm of the protein was evident in 12 patients. Creatine kinase-MB was evaluated by means of a radioimmunoassay, but there was no relation between an increase in the isoenzyme and an increase in myoglobin. No ECG modifications were detected. These data indicate that the measurement of myoglobin may offer an indication of myocardial or skeletal muscle damage caused by adriamycin.

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Consistency analysis of global positioning system position errors with typical statistical distributions

Journal of Navigation ◽

10.1017/s0373463321000485 ◽

2021 ◽

pp. 1-18

Author(s):

Mariusz Specht

Keyword(s):

Normal Distribution ◽

Global Positioning System ◽

Position Error ◽

Statistical Distribution ◽

Positioning System ◽

Statistical Distributions ◽

Position Errors ◽

Global Positioning ◽

Gps System ◽

Best Fit

Abstract Research into statistical distributions of φ, λ and two-dimensional (2D) position errors of the global positioning system (GPS) enables the evaluation of its accuracy. Based on this, the navigation applications in which the positioning system can be used are determined. However, studies of GPS accuracy indicate that the empirical φ and λ errors deviate from the typical normal distribution, significantly affecting the statistical distribution of 2D position errors. Therefore, determining the actual statistical distributions of position errors (1D and 2D) is decisive for the precision of calculating the actual accuracy of the GPS system. In this paper, based on two measurement sessions (900,000 and 237,000 fixes), the distributions of GPS position error statistics in both 1D and 2D space are analysed. Statistical distribution measures are determined using statistical tests, the hypothesis on the normal distribution of φ and λ errors is verified, and the consistency of GPS position errors with commonly used statistical distributions is assessed together with finding the best fit. Research has shown that φ and λ errors for the GPS system are normally distributed. It is proven that φ and λ errors are more concentrated around the central value than in a typical normal distribution (positive kurtosis) with a low value of asymmetry. Moreover, φ errors are clearly more concentrated than λ errors. This results in larger standard deviation values for φ errors than λ errors. The differences in both values were 25–39%. Regarding the 2D position error, it should be noted that the value of twice the distance root mean square (2DRMS) is about 10–14% greater than the value of R95. In addition, studies show that statistical distributions such as beta, gamma, lognormal and Weibull are the best fit for 2D position errors in the GPS system.

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