Relationship of Pre-season Training Load With In-Season Biochemical Markers, Injuries and Performance in Professional Soccer Players

IntroductionThere is controversy in the literature in regards of the link between training load and injury rate. Thus, the aims of this non-interventional study were to evaluate relationships between pre-season training load with biochemical markers, injury incidence and performance during the first month of the competitive period in professional soccer players.Materials and MethodsHealthy professional soccer players were enrolled in this study over two pre-season periods. Data sets were available from 26 players during the first season (2014–2015) and 24 players during the second season (2015–2016) who completed two pre-season periods (6 weeks each). External training load was assessed from all athletes during training using Global Positioning System (GPS). Internal training load was monitored after each training session using rate of perceived exertion (RPE). Before and after each pre-season, blood samples were taken to determine plasma lactate dehydrogenase (LDH), creatine kinase (CK) and C-reactive protein (CRP). Injury incidence and overall performance (ranking of the team after the first five official games of the championship) were recorded for both seasons separately.ResultsThere was no statistically significant difference in mean RPE values of the two-preparation periods (2737 ± 452 and 2629 ± 786 AU, p = 0.492). The correlational analysis did not reveal significant associations between internal and external training load (RPE and GPS data) and biological markers. There was a significant positive correlation between RPE and LDH during the 2015/2016 season (r = 0.974, p = 0.001). In addition, a significant negative correlation was found between total distance >20 km/h and CRP during the 2015–2016 season (r = -0.863, p = 0.027). The injury rates for the two seasons were 1.76 and 1.06 per 1000 h exposure for the 2014–2015 and 2015–2016 seasons, respectively (p = 0.127).ConclusionOur study showed that pre-season training load is not associated with overall team performance. This association is most likely multifactorial and other factors (e.g., technical and tactical level of the team, opponents, environment) may play an important role for the collective team performance. Our findings may help coaches to better prepare their athletes during pre-season

Postural control in Tunisian soccer players

La relation entre la contribution de la vision et le niveau d’expertise sur le contrôle postural semble dépendre du sport pratiqué. Le but de notre travail est d’analyser le contrôle postural et l’utilisation de l’information visuelle chez les footballeurs en fonction de leur niveau de compétition. Méthodes : Deux groupes de footballeurs ont été étudiés : groupe amateurs (AM) niveau régional (n = 16) et un groupe de professionnels au niveau national (PRO) (n = 16). Le paramètre postural a été évalué en mesurant la vitesse d’oscillation du centre de gravité (CG) avec une force plate-forme « Balance Master® » lors d’un essai (30 s) en appui bipodal et unipodal yeux ouverts, et puis, yeux fermés. Résultats : La vitesse d’oscillation de CG est significativement plus élevée dans le groupe AM que dans le groupe PRO en condition yeux ouverts et yeux fermés. La vision et le facteur surface engendrent des différences statistiquement significatives chez les deux groupes (p < 0,05). La fermeture des yeux en condition appui bipodal sur sol souple a entraîné une augmentation des vitesses d’oscillation du CG du groupe AM par rapport à celle du le groupe PRO (p < 0,05). Conclusion : Le rôle de la vison chez les footballeurs de niveau professionnel est moins important dans le maintien de l’équilibre que celui des footballeurs amateurs. Mots clés : Contrôle postural; Footballeur; Vision; Exper

Postural control in Tunisian soccer players

La relation entre la contribution de la vision et le niveau d’expertise sur le contrôle postural semble dépendre du sport pratiqué. Le but de notre travail est d’analyser le contrôle postural et l’utilisation de l’information visuelle chez les footballeurs en fonction de leur niveau de compétition. Méthodes : Deux groupes de footballeurs ont été étudiés : groupe amateurs (AM) niveau régional (n = 16) et un groupe de professionnels au niveau national (PRO) (n = 16). Le paramètre postural a été évalué en mesurant la vitesse d’oscillation du centre de gravité (CG) avec une force plate-forme « Balance Master® » lors d’un essai (30 s) en appui bipodal et unipodal yeux ouverts, et puis, yeux fermés. Résultats : La vitesse d’oscillation de CG est significativement plus élevée dans le groupe AM que dans le groupe PRO en condition yeux ouverts et yeux fermés. La vision et le facteur surface engendrent des différences statistiquement significatives chez les deux groupes (p < 0,05). La fermeture des yeux en condition appui bipodal sur sol souple a entraîné une augmentation des vitesses d’oscillation du CG du groupe AM par rapport à celle du le groupe PRO (p < 0,05). Conclusion : Le rôle de la vison chez les footballeurs de niveau professionnel est moins important dans le maintien de l’équilibre que celui des footballeurs amateurs. Mots clés : Contrôle postural; Footballeur; Vision; Exper

Strength Training Reduce Injury Rate In Elite Young Soccer Players During One Season

International audienceThe purpose of this study was to examine the effect of strength training on physical fitness parameters and injuries occurrence in young elite soccer players.Fifty-two elite young soccer players (13-14 yrs) were divided on a randomized order on Experimental Group (EG, n=26) and Control Group (CG, n=26). For EG, 2 to 3 sessions of strength training (90min) were introduced weekly in their training program for 12 weeks (4x3 weeks separated by 1 week recovery). Sprint tests (10-20-30m), T-test time, and jumping tests, were measured at the start (T0), at the middle (T1), and at the end of the experiment period (T2). The injury rate was recorded by the medical and fitness training staff throughout the soccer season.Compared to CG, EG performed significantly better in sprint running and T-test time at T2 (p\textless0.01). Similarly, the improvement amount for jumping tests was significantly greater (p\textless0.05) in EG compared to CG. A total of 17 injuries were recorded over the soccer season. The rate was higher in CG (13 injuries) compared to TG (4 injuries). This study showed that strength training accurately and efficiently scheduled in youth soccer players, induced performance improvement and reduced the rate of injurie

The Effects of Resistance Training on Muscular Fitness, Muscle Morphology, and Body Composition in Elite Female Athletes: A Systematic Review

International audienceBackground Well programmed strength and conditioning training is an indispensable part of the long-term training process for athletes in individual and team sports to improve performance and prevent injuries. Yet, there is a limited number of studies available that examine the effects of resistance training (RT) on muscular fitness and physiological adaptations in elite female athletes. Objectives This systematic review aimed to summarize recent evidence on the long-term effects of RT or combinations of RT with other strength-dominated exercise types on muscular fitness, muscle morphology, and body composition in female elite athletes. Materials and Methods A systematic literature search was conducted in nine electronic databases ( Academic Search Elite, CINAHL, ERIC, Open Access Theses and Dissertations, Open Dissertations, PsycINFO, PubMed/MEDLINE, Scopus, and SPORTDiscus) from inception until March 2022. Key search terms from the MeSH database such as RT and strength training were included and combined using the operators &quot;AND,&quot; &quot;OR,&quot; and &quot;NOT&quot;. The search syntax initially identified 181 records. After screening for titles, abstracts, and full texts, 33 studies remained that examined the long-term effects of RT or combinations of RT with other strength-dominated exercise types on muscular fitness, muscle morphology, and body composition in female elite athletes. Results Twenty- four studies used single-mode RT or plyometric training and nine studies investigated the effects of combined training programs such as resistance with plyometric or agility training, resistance and speed training, and resistance and power training. The training duration lasted at least 4 weeks, but most studies used similar to 12 weeks. Studies were generally classified as 'high-quality' with a mean PEDro score of 6.8 (median 7). Irrespective of the type or combination of RT with other strength-dominated exercise regimens (type of exercise, exercise duration, or intensity), 24 out of 33 studies reported increases in muscle power (e.g., maximal and mean power; effect size [ES]: 0.23 &lt; Cohen's d &lt; 1.83, small to large), strength (e.g., one-repetition-maximum [1RM]; ES: 0.15 &lt; d &lt; 6.80, small to very large), speed (e.g., sprint times; ES: 0.01 &lt; d &lt; 1.26, small to large), and jump performance (e.g., countermovement/squat jump; ES: 0.02 &lt; d &lt; 1.04, small to large). The nine studies that examined the effects of combined training showed significant increases on maximal strength (ES: 0.08 &lt; d &lt; 2.41, small to very large), muscle power (ES: 0.08 &lt; d &lt; 2.41, small to very large), jump and sprint performance (ES: 0.08 &lt; d &lt; 2.41, small to very large). Four out of six studies observed no changes in body mass or percentage of body fat after resistance or plyometric training or combined training (ES: 0.026 &lt; d &lt; 0.492, small to medium). Five out of six studies observed significant changes in muscle morphology (e.g., muscle thickness, muscle fiber cross-sectional area; ES: 0.23 &lt; d &lt; 3.21, small to very large). However, one study did not find any changes in muscle morphology (i.e., muscle thickness, pennation angle; ES: 0.1 &lt; d &lt; 0.19, small). Conclusion Findings from this systematic review suggest that RT or combined RT with other strength-dominated exercise types leads to significant increases in measures of muscle power, strength, speed, and jump performance in elite female athletes. However, the optimal dosage of programming parameters such as training intensity and duration necessary to induce large effects in measures of muscular fitness and their physiological adaptations remain to be resolved in female elite athletes

Effects of Combined Balance and Strength Training on Measures of Balance and Muscle Strength in Older Women With a History of Falls

International audienceObjective: We investigated the effects of combined balance and strength training on measures of balance and muscle strength in older women with a history of falls. Methods: Twenty-seven older women aged 70.4 +/- 4.1 years (age range: 65 to 75 years) were randomly allocated to either an intervention (IG, n = 12) or an active control (CG, n = 15) group. The IG completed 8 weeks combined balance and strength training program with three sessions per week including visual biofeedback using force plates. The CG received physical therapy and gait training at a rehabilitation center. Training volumes were similar between the groups. Pre and post training, tests were applied for the assessment of muscle strength (weight-bearing squat [WBS] by measuring the percentage of body mass borne by each leg at different knee flexions [0 degrees, 30 degrees, 60 degrees, and 90 degrees], sit-to-stand test [STS]), and balance. Balance tests used the modified clinical test of sensory interaction (mCTSIB) with eyes closed (EC) and opened (EO), on stable (firm) and unstable (foam) surfaces as well as spatial parameters of gait such as step width and length (cm) and walking speed (cm/s). Results: Significant group x time interactions were found for different degrees of knee flexion during WBS (0.0001 &lt; p &lt; 0.013, 0.441 &lt; d &lt; 0.762). Post hoc tests revealed significant pre-to-post improvements for both legs and for all degrees of flexion (0.0001 &lt; p &lt; 0.002, 0.697 &lt; d &lt; 1.875) for IG compared to CG. Significant group x time interactions were found for firm EO, foam EO, firm EC, and foam EC (0.006 &lt; p &lt; 0.029; 0.302 &lt; d &lt; 0.518). Post hoc tests showed significant pre-to-post improvements for both legs and for all degrees of oscillations (0.0001 &lt; p &lt; 0.004, 0.753 &lt; d &lt; 2.097) for IG compared to CG. This study indicates that combined balance and strength training improved percentage distribution of body weight between legs at different conditions of knee flexion (0 degrees, 30 degrees, 60 degrees, and 90 degrees) and also decreased the sway oscillation on a firm surface with eyes closed, and on foam surface (with eyes opened or closed) in the IG. Conclusion: The higher positive effects of training seen in standing balance tests, compared with dynamic tests, suggests that balance training exercises including lateral, forward, and backward exercises improved static balance to a greater extent in older women

Reference database of the gait cycle for young healthy Tunisian adults

Background. - Quantified gait analysis is a rising technology used increasingly to assess motor disorders. Normal reference data are required inorder to evaluate patients, but there are no reference data available for the Tunisian healthy population.Aim. - To assess the features of normal Tunisian gait pattern, and examine the intrinsic reliability of spatio-temporal, kinematic and kineticparameters within a new specific reference database. Methods. - Eighteen healthy active-young adults (age: 23.30 ± 2.54 years, height: 1.78 ± 0.04 m and, weight: 70.00 ± 4.80 kg) have participated tofive trials of step gait where the dominant lower limb were recorded. Two over the five trials were randomly selected to be further analyzed. Twenty-three spatio-temporal, kinematic and kinetic parameters determined from 3-dimensional gait analysis. The intrinsic reliability was examined foreach variable and our results were compared with those available in the literature.Results. - Twelve over 23 parameters have an excellent intrinsic reliability (P &#62; 0.05, ICC &#62; 0.9 and SEM &#60; 5% of the grand mean). There aresimilarities with other studies (P &#60; 0.05) but we noticed the existence of some specificity (the height of hip extension peak and the low cadence ofgait) that could characterize the Tunisian population. Conclusion. - A specific reference database of the gait cycle has been established for healthy Tunisian active-young adults and excellent inter-trialreliability may be observed for different variables