End Of Preseason Research Articles

Anthropometric and Body Composition Changes during Pre-Season of Spanish Professional Female Soccer Players According to Playing Position.

In professional soccer, body composition analysis is crucial to assess preparation and optimize performance. Different playing positions have different physical demands, which can lead to variations in body composition. However, there are few studies on women's soccer that consider the playing position. This study aims to fill that gap by examining position-specific differences in anthropometric and body composition characteristics among Spanish professional female soccer players at the beginning and end of pre-season. Furthermore, it investigates the possible changes during the pre-season period between positions and correlates the data obtained from anthropometric equations with bioimpedance (BIA) measurements. Thirty-four female soccer players: 8 midfielders, 12 defenders, 11 forwards, and 3 goalkeepers (age: 23.06 ± 4.29 years, height: 164.15 ± 5.84 cm, weight: 58.39 ± 6.62 kg, and ∑6 skinfolds: 74.57 ± 18.48 mm) completed the study that lasted 4 weeks (pre-season) where they were measured anthropometrically and by bioimpedance twice. Goalkeepers showed greater wingspan (176.60 ± 7.06 p < 0.05) compared to other positions. Regarding differences during pre-season, midfielders had the greatest decrease in ∑6 skinfolds compared to other positions (∆ -12.10 ± 5.69 p < 0.05). There was a correlation of % fat between Faulkner's equation and BIA (Pearson's r = 0.817). It seems that there are no significant differences in terms of positions and body composition, except for the wingspan and ankle diameter. During pre-season, midfielders are the ones who improve their body composition the greatest. The anthropometric equation for body fat that shows the highest correlation with BIA is Faulkner's equation, followed by Durnin's equation.

Seasonal Muscular Power Changes: Considerations of Concurrent Resistance and Field-Based Training in Professional Rugby League.

Redman, KJ, Wade, L, Whitley, R, Connick, MJ, Kelly, VG, and Beckman, EM. Seasonal muscular power changes: considerations of concurrent resistance and field-based training in professional rugby league. J Strength Cond Res 38(9): 1620-1626, 2024-A rugby league player's ability to develop or maintain lower-body power will be significantly influenced by the resistance and field-based training loads completed. This study aimed to examine the power changes across a rugby league season and to investigate the relationship of concurrent training and training experience on power changes. Eighteen rugby league players participated in this study. Lower-body power was evaluated using a countermovement jump throughout the season. Four measures of external training loads were collected. A Friedman's test was used to assess differences in power throughout different phases of the season. A series of Spearman's rank-order correlations were conducted to assess the relationship between percentage changes in power during the training block, external training loads, and training experience. Countermovement jump peak velocity significantly decreased from the start ( p = 0.006) and end of pre-season ( p = 0.022) to the late competition. Correlation analysis revealed a large significant association between early competition field-based external loads (relative ( rs = -0.571) and total distance ( rs = -0.628)) and change in peak power. Very large significant negative relationships were also observed between mid-competition volume load with change in peak force ( rs = -0.825) and peak power ( rs = -0.736). Training experience was not significantly associated with changes in muscular power variables throughout this study. Coaches should seek to monitor changes in peak power when competition begins and to assist with decision-making for potential adjustments to running volume and intensity during field-based sessions.

The Evolution of Physical Performance throughout an Entire Season in Female Football Players.

Research on the evolution of performance throughout a season in team sports is scarce and mainly focused on men's teams. Our aim in this study was to examine the seasonal variations in relevant indices of physical performance in female football players. Twenty-seven female football players were assessed at week 2 of the season (preseason, PS), week 7 (end of preseason, EP), week 24 (half-season, HS), and week 38 (end of season, ES). Similar to the most common used conditioning tests in football, testing sessions consisted of (1) vertical countermovement jump (CMJ); (2) 20 m running sprint (T20); (3) 25 m side-step cutting maneuver test (V-CUT); and (4) progressive loading test in the full-squat exercise (V1-LOAD). Participants followed their normal football training procedure, which consisted of three weekly training sessions and an official match, without any type of intervention. No significant time effects were observed for CMJ height (p = 0.29) and T20 (p = 0.11) throughout the season. However, significant time effects were found for V-CUT (p = 0.004) and V1-LOAD (p = 0.001). V-CUT performance significantly improved from HS to ES (p = 0.001). Significant increases were observed for V1-LOAD throughout the season: PS-HS (p = 0.009); PS-ES (p < 0.001); EP-ES (p < 0.001); and HS-ES (p = 0.009). These findings suggest that, over the course of the season, female football players experience an enhancement in muscle strength and change of direction ability. However, no discernible improvements were noted in sprinting and jumping capabilities during the same period.

Seasonal health tracking of Australian Football League Women’s athletes

ABSTRACT Background Studies evaluating the dietary intake of Australian Football League Women’s (AFLW) athletes are few and limited to the preseason. This prospective observational study aims to evaluate seasonal changes in dietary intake and health parameters of professional AFLW athletes. Methodology Dietary intake (3-day weighed food records), body composition (bioelectrical impedance analysis, skinfolds), physical performance (global positioning system, GPS), and iron status (fasted blood sample) were assessed in 19 athletes (24 ± 5 years, 170 ± 6 cm, 22.8 ± 2.1 kg/m2) at three timepoints: start of preseason, end of preseason, and end of competition season. Sociodemographic information, sports nutrition knowledge (SNK), and risk of low energy availability (LEA) questionnaires were completed at the start of preseason. Results Mean daily energy and carbohydrate (CHO) intakes were lower than recommendations across all seasons (p < 0.05). Mean daily CHO intake was highest at start of preseason (3.6 g/kg/day), decreased during preseason (3.1 g/day) and remained low during competition (3.2 g/day); >80% of players did not meet minimum recommendations at each timepoint (all, p < 0.05). The sum of seven skinfolds and fat mass (%) decreased during preseason (both, p < 0.05). Serum iron fell within recommended ranges for 95% of athletes at all timepoints. The total distance (m) and number of Very High Intensity (>21 km/h) efforts significantly increased across preseason and decreased during competition (all, p < 0.05). Nutrition knowledge was ‘poor’, and 42% of athletes were at risk of LEA. Conclusions AFLW athletes do not meet energy and carbohydrate requirements across the preseason and competition seasons, which may impact health and performance if deficits are sustained.

Plasma Volume Variations in Professional Soccer Players: Difference Between Pre- and Competitive Season

Background: Variations in plasma volume and hematological parameters occur before and after training in soccer players. However, there are no reports on changes in hematological parameters resulting from a half-season of training in professional soccer players. Objectives: To investigate the effects of training load on plasma volume variations in elite soccer players. Methods: Twenty soccer players from the 1st French division soccer league (Ligue 1) were included in the study. The training load was evaluated using the rating of perceived exertion (RPE, 10- Borg scale) after each training session and each match. Anthropometrics characteristics, hematocrit (Ht), hemoglobin (Hb) and plasma volume variations (PVV) were assessed at 3 different times: T1: Baseline (before the first week of pre-season), T2: At the end of pre-season (after 8 weeks of training) and T3: At the end of the first competitive period (after 26 weeks of training and at halfway of the competitive season). Results: Values of Ht and lean body mass (LBM) increased during the first competitive period from T1 to T3 (Ht: ∆↑8%, P = 0.037, effect sizes (ES) = 1.0; LBM: ∆↑4%, P = 0.041, ES = 0.83) and from T2 to T3 (LBM: (∆↑2%; P = 0.05; ES = 0.77). Moreover, PVV decreased from T2 to T3 (P = 0.002, ES = 0.5) and from T1 to T3 (P &lt; 0.05; ES = 1.26). There were no differences in Hb at T1, T2 or T3. Conclusions: Changes in body weights, PVV and Ht during preparatory and competitive phases were affected by the training load and competitive play.

Plasma Volume Variations in Professional Soccer Players: Difference Between Pre- and Competitive Season

Background: Variations in plasma volume and hematological parameters occur before and after training in soccer players. However, there are no reports on changes in hematological parameters resulting from a half-season of training in professional soccer players. Objectives: To investigate the effects of training load on plasma volume variations in elite soccer players. Methods: Twenty soccer players from the 1st French division soccer league (Ligue 1) were included in the study. The training load was evaluated using the rating of perceived exertion (RPE, 10- Borg scale) after each training session and each match. Anthropometrics characteristics, hematocrit (Ht), hemoglobin (Hb) and plasma volume variations (PVV) were assessed at 3 different times: T1: Baseline (before the first week of pre-season), T2: At the end of pre-season (after 8 weeks of training) and T3: At the end of the first competitive period (after 26 weeks of training and at halfway of the competitive season). Results: Values of Ht and lean body mass (LBM) increased during the first competitive period from T1 to T3 (Ht: ∆↑8%, P = 0.037, effect sizes (ES) = 1.0; LBM: ∆↑4%, P = 0.041, ES = 0.83) and from T2 to T3 (LBM: (∆↑2%; P = 0.05; ES = 0.77). Moreover, PVV decreased from T2 to T3 (P = 0.002, ES = 0.5) and from T1 to T3 (P &lt; 0.05; ES = 1.26). There were no differences in Hb at T1, T2 or T3. Conclusions: Changes in body weights, PVV and Ht during preparatory and competitive phases were affected by the training load and competitive play.

Sprinting, Strength, and Architectural Adaptations Following Hamstring Training in Australian Footballers.

The aim of this study was to determine the sprinting, strength, and architectural adaptations following a hip-dominant flywheel (FLY) or Nordic hamstring exercise (NHE) intervention in Australian footballers. Twenty-seven male athletes were randomized to FLY (n=13) or NHE (n=14) training across a 39-week period (inclusive of pre-season and in-season). Biceps femoris long head (BFlh) architecture was assessed throughout. Eccentric hamstring strength and 40m sprint times (with force-velocity profiling) were assessed at baseline, end of pre-season, and following the intervention. After the intervention, BFlh fascicle length was longer in both groups compared to baseline (FLY: 1.16cm, 95%CI: 0.66 to 1.66cm, d=1.99, p<0.001; NHE: 1.08cm, 95%CI: 95%CI 0.54 to 1.61cm, d=1.73, p<0.001). Both groups also increased their eccentric strength (FLY: mean change 82N, 95%CI 12 to 152N, d=1.34, p=0.026; NHE: mean change 97N, 95%CI 47 to 146N, d=1.77, p=0.001). After pre-season, the NHE group improved their 5m sprint time by 3.5% (±1.2%) and were 3.7% (±1.4%) and 2.0% (±0.5%) faster than the FLY group across 5m and 10m, respectively. At the end of pre-season, the FLY group improved maximal velocity by 3.4% (±1.4%) and improved horizontal force production by 9.7% in-season (±2.2%). Both a FLY and NHE intervention increase BFlh fascicle length and eccentric strength in Australian Footballers. An NHE intervention led to enhanced acceleration capacity. A FLY intervention was suggested to improve maximal sprint velocity and horizontal force production, without changes in sprint times. These findings have implications for hamstring injury prevention but also programs aimed at improving sprint performance.

Changes in markers of body composition of professional male soccer players during pre-season

To evaluate changes achieved in whole-body and regional (upper limbs, lower limbs, and trunk) estimates of body composition, twenty professional male soccer players (7 defenders, 7 midfielders, 6 forwards) underwent dual-energy x-ray absorptiometry (DXA) analysis at the beginning and end of pre-season. Measures included: mass, fat mass (FM), fat-free mass (FFM), and body fat per cent (BF%). Players’ activity during on-field training sessions was monitored using Global Positioning System (GPS) units, with GPS data used to obtain estimations of energy expenditure (EE). Whole-body mass remained unchanged across the pre-season. Moderate significant increases and decreases were achieved in whole-body FFM (Pre: 59.58 ± 5.27 kg; Post: 60.61 ± 5.18 kg; p = 0.001; d = 0.87) and FM (Pre: 10.60 ± 1.88 kg; Post: 9.56 ± 1.81 kg; p = 0.001; d = 0.85), respectively. Moderate significant decreases were achieved in whole-body BF% (Pre: 14.4 ± 2.3%; Post: 12.9 ± 2.0%; p < 0.001; d = 0.94). No significant inter-positional differences were observed for the changes achieved in any global or regional estimate of body composition. Total EE was significantly correlated with ΔFM (r = 0.65, p = 0.002), ΔFFM (r = 0.46, p = 0.03), and ΔBF% (r = 0.67, p = 0.002). The total EE of pre-season training accounted for 42%, 21%, and 45% of the variance in ΔFM, ΔFFM, and ΔBF%, respectively. These findings suggest that the pre-season period is a suitable time for initiating favourable alterations in body composition following the off-season in elite soccer players.

Does the longitudinal development of physical and anthropometric characteristics associate with professional career attainment in adolescent Australian footballers?

This study sought to longitudinally and retrospectively determine the relationship between professional career attainment and the development of anthropometric and physical qualities in junior Australian footballers. Eighty adolescent male Australian footballers from a single state academy previously selected onto an under 16 s talent development squad were classified by career attainment (professional team selection; n = 17 and non-selected; n = 63). Physical and anthropometric tests were conducted at the end of preseason during participation in under 16 and under 18 competitions. Tests included standing height, mass, stationary countermovement jumps, dynamic vertical jumps, 20-m sprints, agility and 20 m multistage fitness test. Both groups significantly improved all performance measures between the under 16 and under 18 levels. Athletes selected onto a professional team possessed significantly quicker 20-m sprint outcomes than non-selected athletes at both under 16 and under 18 levels, highlighting the importance of this physical capacity within talent development programmes. Binary logistic regression was unable to predict an effect of any measures on career attainment. An inability of the binary logistic regression to identify qualities predictive of long-term career success likely highlights limitations associated with utilising unidimensional models of assessment in talent identification practices. As such, development coaches and sport scientists should be aware that while physical capacities play a role in career attainment outcomes, other factors, such as tactical understanding and technical skill are also likely to be impactful.

Hip adduction and abduction strength and adduction-to-abduction ratio changes across an Australian Football League season

ObjectivesPre-season hip strength testing only represents the athlete’s level of conditioning at that time point, and may change over an Australian Football (AF) season. This study aimed to examine if there are changes in hip adduction, abduction and the adduction-to-abduction ratio between preferred and non-preferred kicking legs throughout an AF season. The influence of training load and player characteristics was also examined. DesignCross-sectional repeated measures. Methods38 uninjured elite AF players were included. Maximal isometric hip adduction and abduction strength were measured at four time points: start of pre-season (T1), end of pre-season (T2), mid-season (T3) and post-season (T4) using a hand held dynamometer with external belt fixation. ResultsHip adduction strength and hip-adduction-to-abduction ratio were greater in T3 compared to T1 (adduction by 22.71N, p<0.001, ratio by 0.15N, p<0.001) and hip adduction and abduction were weaker in T4 compared to T1 (adduction by 18.6N, p=0.004, abduction by 24.67N, p<0.001). No differences were found between the preferred and non-preferred leg in adduction (p=0.409) or abduction (p=0.602) strength. There was an interaction between leg and time point for the adduction-to-abduction ratio; at T3 and T4, the ratio of the preferred kicking leg was significantly lower than the non-preferred kicking leg (T3 by 0.14N, p=0.020, T4 by 0.15N, p=0.019). Training load was not significantly associated with strength changes. ConclusionsHip strength does change over an AF season. Regular in-season hip strength testing should occur to more accurately reflect player condition compared to one pre-season measurement.

Relationship between vertical stiffness and soft-tissue injuries in professional Australian football

ABSTRACT Soft-tissue injuries are common in Australian football. Recently, literature has identified non-modifiable and modifiable risk factors, including vertical stiffness (Kvert). However, limitations regarding measurement frequency and duration exist; thus, further information is required about the role of Kvert as a modifiable risk factor for injury. This study examined the seasonal variation in Kvert and its relationship to soft-tissue injuries in professional Australian football. The mean Kvert and bilateral asymmetry were assessed and compared between injured and non-injured players. For the seasonal analysis, 56 players were tested across two seasons with no variation in bilateral asymmetry evident (p= 0.33). While there were generally no changes in Kvert, the value from the end of the second pre-season revealed 5% lower values than the mean of two seasons (p= 0.02). Considering the injury analysis, 21 lower-body soft-tissue injuries were recorded from 18 participants. No differences were recorded for mean Kvert between the injured and non-injured groups (p= 0.16–0.76). When assessing Kvert asymmetry, the injured group displayed a 4.5% higher value than the non-injured group at the end of the pre-season test (p= 0.03) but not at other time-points (p= 0.16–0.99). Higher Kvert bilateral asymmetry measures after the pre-season appear to be related to lower-body soft-tissue injury in professional Australian footballers. Medical and conditioning staff should consider this measure when trying to mitigate the onset of injury or identify at-risk players.

Relationship Between Physical Fitness at the End of Preseason and the Inseason Game Performance in Japanese Female Professional Baseball Players.

Watanabe, Y, Yamada, Y, Yoshida, T, Matsui, T, Seo, K, Azuma, Y, Hiramoto, M, Miura, Y, Fukushima, H, Shimazu, A, Eto, T, Saotome, H, Kida, N, and Morihara, T. Relationship between physical fitness at the end of preseason and the inseason game performance in Japanese female professional baseball players. J Strength Cond Res 33(6): 1580-1588, 2019-This study examined anthropometric and fitness profiles of Japanese female professional baseball players and investigated the relationship between players' physical fitness and inseason game performance. Fifty-seven players who were registered in the Japan Women's Baseball League (JWBL) participated. Height, body mass, grip strength, back strength, knee extension and flexion strength, hamstring extensibility, vertical jump height, and horizontal jump distance were measured at preseason (February and March) in 2013. Game performance during the 2013 season (March-November) was obtained from official JWBL statistics. Vertical jump height showed significant positive correlations with individual performance records (e.g., total bases [r = 0.551], slugging percentage [r = 0.459], and stolen bases [r = 0.442]). Similar relationships were observed between horizontal jump distance and performance statistics in most cases. By contrast, grip, back, and lower-limb strength, as well as hamstring extensibility were not significantly correlated with game performance. Stepwise regression analysis selected vertical jump height as an independent variable, significantly correlating with several game performance measures (e.g., total bases: adjusted R = 0.257). Also, vertical jump height and body mass index were identified as independent variables significantly associated with stolen bases (adjusted R = 0.251). Maximal jump performance, rather than simple isometric muscle strength or flexibility, is a good performance test that can be used at the end of preseason to predict inseason batting and stolen base performance. Our findings demonstrate the importance of constructing preseason training programs to enhance lower-limb muscular power that is linked to successful inseason performance in female baseball players.

Effect of Competitive Training on Antiviral Immune Activity in Collegiate Gymnasts

Regular moderate exercise has numerous health benefits, including positive effects on immune function, although periods of intense training may increase susceptibility to respiratory tract pathogens such as influenza virus. PURPOSE: To determine the effect of intense athletic training on the antiviral immune response profile and to examine the effect of ingestion of eggs on this response. METHODS: Female participants from a Division I varsity gymnastics team were recruited and either consumed whole eggs daily (E; n = 7) or maintained their normal diets (NE; n = 6) for the duration of the study. Blood was collected at three time points: before the high intensity pre-season training began (T1), one month into pre-season (T2), and two months after T2 at the end of pre-season (T3). Peripheral blood mononuclear cells (PBMCs) were isolated from whole blood, cultured ex vivo, and challenged with influenza A/PR/8/34 for 24 hours. Cell supernatants were analyzed using a multiplex cytokine array assay. RESULTS: Statistical analyses revealed lower levels of cytokines involved in both innate (IL-1β, IL-6, TNFα) and T cell-mediated immunity (IFNγ, IL-2, IL-7) produced in response to virus stimulation at T2 (6.8, 87.3, 351, 731, 82.0, and 3.2 pg/mL, respectively) compared to T1 (12.1, 317, 534, 2469, 311, and 5.5 pg/mL, respectively) and T3 (17.4, 268, 712, 3018, 212, and 5.1 pg/mL, respectively; p &lt; 0.05, paired t-tests). PBMCs from gymnasts who became ill during the study period (n = 3) produced less IFNα (427 vs. 1442 pg/mL) at T2 and more sCD40L (11.6 vs. 5.8 pg/mL) at T3 than those who remained healthy (p &lt; 0.05, independent t-tests). When egg consumption was examined, a mixed ANOVA with repeated measures revealed a significant treatment by time interaction and follow-up post hoc tests identified differences in inflammatory cytokine production at T3 (12.3 vs. 23.3 and 496 vs. 963 pg/mL for IL-1β and IL-6, respectively, in E vs. NE; p &lt; 0.05). CONCLUSION: These preliminary data suggest that, during intense training, both innate and adaptive antiviral defenses are impaired but that egg consumption may attenuate training-associated inflammation. Increases in immunosuppressive proteins, such as sCD40L, may also increase susceptibility to illness in athletes. Funding was provided by the Iowa Egg Council and Egg Nutrition Center.

The influence of` preseason training phase and training load on body composition and its relationship with physical qualities in professional junior rugby league players

ABSTRACTThis study investigated changes in body composition in relation to training load determined using RPE and duration (sRPE), and its relationship with physical qualities over a preseason period. Sixteen professional academy players (age = 17.2 ± 0.7 years; stature = 179.9 ± 4.9 cm; body mass = 88.5 ± 10.1 kg) participated in the study. Body composition was assessed before and after each training phase and physical qualities assessed at the start and end of preseason. Across the whole preseason period, skinfold thickness, body fat percentage and fat mass were most likely lower (ES = −0.73 to −1.00), and fat free mass and lean mass were likely to most likely higher (ES = 0.31 to 0.40). Results indicated that the magnitude of change appeared phase-dependent (ES = −0.05 to −0.85) and demonstrated large individual variability. Changes in physical qualities ranged from unclear to most likely (ES = −0.50 to 0.64). Small to moderate correlations were observed between changes in body composition, and TL with changes in physical qualities. This study suggests training phase and TL can influence a player’s body composition; that large inter-participant variability exists; and that body composition and TL are related to the change in physical qualities.

The effect of low back pain on trunk muscle size/function and hip strength in elite football (soccer) players

ABSTRACTLow back pain (LBP) is a common problem in football (soccer) players. The effect of LBP on the trunk and hip muscles in this group is unknown. The relationship between LBP and trunk muscle size and function in football players across the preseason was examined. A secondary aim was to assess hip muscle strength. Twenty-five elite soccer players participated in the study, with assessments conducted on 23 players at both the start and end of the preseason. LBP was assessed with questionnaires and ultrasound imaging was used to assess size and function of trunk muscles at the start and end of preseason. Dynamometry was used to assess hip muscle strength at the start of the preseason. At the start of the preseason, 28% of players reported the presence of LBP and this was associated with reduced size of the multifidus, increased contraction of the transversus abdominis and multifidus muscles. LBP decreased across the preseason, and size of the multifidus muscle improved over the preseason. Ability to contract the abdominal and multifidus muscles did not alter across the preseason. Asymmetry in hip adductor and abductor muscle strength was found between players with and without LBP. Identifying modifiable factors in players with LBP may allow development of more targeted preseason rehabilitation programmes.

Effect of Mouthgaurd and Stick Use on Aerobic Capacity High School Field Hockey Athletes

Many sports require the use of a mouthguard (MG) and the constraint of carrying a stick during play. Previous research has shown that these two conditions individually cause decrements to athletic performance; however, no research has been conducted on the effect of the combination of these conditions. PURPOSE:To determine effects of chronic MG and stick use during field hockey (FH) specific training on aerobic capacity; and to determine effects of acute use of MG and stick on aerobic capacity regardless of training group. METHODS:38 healthy female FH players (15+2 yrs.) from a local competitive high school team completed the study. Participants were placed into one of two groups: experimental (completing all conditioning with MG and stick) or control (completing all conditioning without MG and stick) by stratified random sampling matched for team level (Freshman, Junior Varsity or Varsity) and initial beep test performance. The beep test is a 20m multistage test that involves running in time with pre-recorded beeps. FH-specific training was performed as prescribed by coaching staff, with testing performed at baseline (start of preseason), 6 weeks (end of preseason) and 12 weeks (end of competition). Participants performed two beep tests, one with a MG and stick (MG-STK) and one without a MG and stick (WOMG-STK) during each testing block (baseline, 6 weeks, 12 weeks). Tests were performed >48 hours apart and the effects of MG and stick use were analyzed using a 3-way ANOVA. RESULTS:No difference was found in aerobic capacity between the experimental and control groups (p>0.05). It was determined that performing a beep test with MG and stick resulted in reduced aerobic performance (WOMG-STK: 37.41+6.65 ml·kg-1·min-1 vs. MG-STK: 33.16+5.02 ml·kg-1·min-1; p<0.01). Further, it was found that FH-specific training altered aerobic performance across the 12 weeks (p<0.01). Aerobic performance increased from baseline to midpoint (p0.05) (PRE: 33.37+4.29 ml·kg-1·min-1; MID: 37.52+6.81 ml·kg-1·min-1; POST: 34.94+6.65 ml·kg-1·min-1). CONCLUSIONS:Aerobic capacity was not affected by chronic use of MG and stick during standard FH-specific training. The use of MG and stick during the performance of a beep test diminished aerobic capacity across the study period.

Análise da demanda fisiológica crônica de uma temporada anual de futebol

Exercise intensity monitoring has been essential for the control and planning of sports training. Thus, the aim of the present study was to assess the chronic physiological demand of soccer players during an annual soccer season using blood biomarkers. Ten professional soccer players (21.2 ± 3.7 years) participated in this study. Blood samples were collected on the day before beginning of preseason (C1); at the end of preseason and beginning of competitive calendar (C2); and at the end of the competitive calendar. Interleukin-6 (IL-6), cortisol, testosterone, testosterone/cortisol ratio, creatine kinase and alpha-actin were evaluated. Statistical analysis was performed by using ANOVA with repeated measures and the post-hoc Tukey's test. Significance level was set at P<0.05. The results showed significant differences in the following situations: testosterone - C1 higher than C2 and C3; cortisol - C3 higher than C2; testosterone/cortisol ratio - C2 higher than C1, and C3 lower than C1 and C2; creatine kinase - C2 and C3 higher than C1; alpha-actin - C3 higher than C1. IL-6 concentrations were not different between C1, C2 and C3. It could be concluded that an annual soccer season imposes high physiological demand for professional players, since relevant changes in blood biomarkers analyzed were observed.

Periodization and physical performance in elite female soccer players.

To investigate the variation in training demands, physical performance, and player well-being across a women's soccer season. Seventeen elite female players wore GPS tracking devices during every training session (N=90) throughout 1 national-league season. Intermittent high-speed-running capacity and 5-, 15-, and 25-m-sprint testing were conducted at the beginning of preseason, end of preseason, midseason, and end of season. In addition, subjective well-being measures were self-reported daily by players over the course of the season. Time over 5 m was lowest at the end of preseason (mean 1.148 s, SE 0.017 s) but then progressively deteriorated to the end of the season (P<.001). Sprint performance over 15 m improved by 2.8% (P=.013) after preseason training, while 25-m-sprint performance peaked at midseason, with a 3.1% (P=.05) improvement from the start of preseason, before declining at the end of season (P=.023). Training demands varied between phases, with total distance and high-speed distance greatest during preseason before decreasing (P<.001) during the early- and late-season phases. Endurance capacity and well-being measures did not change across training phases. Monitoring training demands and subsequent physical performance in elite female soccer players allow coaches to ensure that training periodization goals are being met and related positive training adaptations are being elicited.

Changes in muscle strength in u19 soccer players during an annual training cycle.

The aim of the study was to investigate the seasonal variation in isokinetic strength of the knee flexors and extensors, and conventional (H/QCONV) and functional (H/QFUNC) hamstring to quadriceps strength ratios in highly trained adolescent soccer players. The players (n=11; age 17.8±0.3) were measured at the end of the competitive season (autumn), at the beginning and the end of pre-season (winter) and during the sixth week of a new competitive season. Isokinetic peak torque (concentric and eccentric) was measured at 60°·s-1 in a sitting position with the hip flexed at 100°. The testing range of motion was set from 10 – 90° of knee flexion. The players performed a set of five maximum repetitions for both the dominant and non-dominant leg. Statistically significant differences (p<0.001) between the four seasonal measurements were noted for peak torque of the dominant leg knee flexors in concentric muscle action only. A post hoc analysis revealed a statistically significant increase in peak torque from the 1st to the 4th measurement (p<0.001; d=0.692) and from the 2nd to the 4th (p<0.01; d=0.564). The differences in the changes of peak torque of the knee flexors and extensors depending on type of muscle action and tendencies found in the H/Q ratios throughout the annual training cycle indicate that strength assessment of the knee flexors and extensors and their balance throughout the annual training cycle could be beneficial for elite male adolescent soccer players both in terms of performance and risk of injury.

Vertical stiffness and muscle strain in professional Australian football

The purpose of this study was to establish if vertical stiffness was greater in professional Australian rules footballers who sustained a lower limb skeletal muscle strain compared to those who did not, and to establish if a relationship between age, or training history, and vertical stiffness existed. Thirty-one participants underwent weekly rebound jump testing on a force platform over two seasons. Vertical stiffness was calculated for injured players and the uninjured cohort 1 and 3 weeks prior to sustaining an injury and at the end of preseason. Eighteen athletes were in the “uninjured” cohort and 13 in the “injured” cohort. No significant difference in vertical stiffness was observed between groups (P = 0.18 for absolute stiffness; P = 0.08 for stiffness relative to body mass), within groups (P = 0.83 and P = 0.88, respectively) or for a time*cohort interaction (P = 0.77 and P = 0.80, respectively). No relationship between age and vertical stiffness existed (r = −0.06 for absolute and relative stiffness), or training history and vertical stiffness (r = −0.01 and 0.00 for absolute and relative stiffness, respectively) existed. These results and others lend to suggest that vertical stiffness is not related to lower limb muscle strain injury.