ECSS Paris 2023: OP-AP23
INTRODUCTION: The curvilinear sprint (CS) is the most frequently performed type of sprint in football matches and is an important speed skill for footballers [1]. It requires a different running technique than the linear sprint, which leads to performance deficits and asymmetries [2]. While the specificity of CS performance in football players is well established [3], potential sex differences, especially in youth, remain unclear. Furthermore, most research has focused on split times, overlooking key performance metrics that could provide deeper insights into CS demands. The aim of this study was to investigate the effects of sex and CS side dominance on performance, deficits and asymmetries in adolescent football players using a global navigation satellite system. METHODS: Twenty male (16.4±1.2 years, 70.0±6.6 kg, 179.4±6.1 cm) and 20 female (16.3±1.2 years, 58.1±7.2 kg, 167.1±4.6 cm) national team football players completed a linear 30 m and a left/right CS (radius 9.15 m). Distance, speed and acceleration were measured using the GPEXE lt system (Exelio SRL, Udine, Italy). Peak speed (Speak), peak acceleration (Apeak), and acceleration-speed (AS) profiles (A0, S0, ASslope) were calculated. The side with the higher Speak was categorised as stronger. In addition, deficits and asymmetries were calculated from Speak and AS profiles (Sdeficit, ASdeficit, Sasymmetry, ASasymmetry). A two-way ANOVA assessed the effects of dominance (weaker vs. stronger) and sex (male vs. female) on the variables, with partial eta squared (η²) for effect size and Bonferroni post-hoc adjustments. Unpaired t-tests were used to assess differences in Sasymmetry and ASasymmetry. The significance level was set at P<0.05. RESULTS: A significant interaction effect was found for Apeak (F=6.5, p=0.019, η²=0.03), A0 (F=5.8, p=0.026, η²=0.02), and Sdeficit (F=5.8, p=0.026, η²=0.02). Males had significantly greater Apeak and Sdeficit on the stronger side than females (MD=0.43 m/s² and 2.46%; p<0.001). Sex and dominance significantly influenced Speak (F≥98.9, p<0.0001, η²≥0.73) and S0 (F≥62.7, p<0.0001, η²≥0.43), with males achieving higher speeds (MD≥0.87 m/s, p<0.0001) and higher speeds observed on the stronger CS in both sexes (MD≥0.16 m/s, p<0.001). Only dominance influenced ASslope (F=44.7, p<0.0001, η²=0.27) and ASdeficit (F=89.1, p<0.0001, η²=0.59). Weaker CS had steeper ASslope (MD≥0.08 s⁻¹, p<0.015) and greater ASdeficit (MD≥21.49%, p<0.0001). Females had greater Sasymmetry than males (M=2.24 vs. 3.72%, t(38)=2.46, p=0.019), but no differences in ASasymmetry were found (p=0.380). CONCLUSION: Male footballers accelerate faster, reach a higher top speed and have greater deficits, while female show greater asymmetries in CS performance. CS dominance, rather than sex, appears to influence AS profiles. For male footballers, it is important to focus on CS deficits whereas for female footballers, top speed and asymmetries should be the focus of training. 1 Caldbeck et al. 2022, 2 McBurnie et al. 2021, 3 Grazioli et al. 2024
Read CV Matic SašekECSS Paris 2023: OP-AP23
INTRODUCTION: High-Intensity Interval Training (HIIT) has been shown to mitigate performance declines in professional male soccer players during the off-season1. However, its effects in youth female soccer players remain unexplored. This study investigates the impact of a 4-week off-season high-intensity training program on aerobic fitness and sprint endurance in Under-15 female soccer players. METHODS: Fifteen U-15 female soccer players from a professional team completed a 4-week training program consisting of two weekly sessions of small-sided games (SSG) consisting of 4 × 4 minutes with 3 minutes of active recovery (running at low intensity) between bouts, and two weekly sessions of repeated sprint training (RST) consisting of 5 reps x 3 sets of 40-m sprint with a 180° change of direction with a rest of 20 seconds between repetitions and 4 minutes between sets. Performance assessments before and after the intervention Yo-Yo intermittent recovery level 1 test (YYIR1) and 30-second test (30s Test) were performed. Aerobic fitness level and sprint endurance ability were assessed though the YYIR1 and 30s Test, respectively. Furthermore, physiological responses were monitored using heart rate (HR) and blood lactate concentration ([La]+) as internal workload indicators, and total distance (TD), moderate speed distance (DMS), high speed distance (DHS), acceleration distance (≥3 m-s-2, DACC) and deceleration distance (≤3 m-s-2, DDEC) as external workload indicators. RESULTS: Following the intervention, TD significantly increased in both the YYIR1 (p = 0.000) and the 30s Test (p=0.004, respectively). HR and [La]+ significantly increased only in the YYIR1 (p = 0.001), but not in the 30s Test (p = 0.572). A strong correlation was observed between time spent >85% HRmax and TD in the 30s Test (r = 0.73, p = 0.002). Moreover, a significant correlation between time spent at intensity >85% HRmax and percentage change in TD in the 30s test (r=0.73, p=0.002) was observed. Similar correlations were found between time spent >85% HRmax and TD (r = 0.91, p = 0.000) and percentage change in TD (r = 0.83, p = 0.001) in YYIR1. Finally, strong correlations were observed between DMS and TD in YYIR1 (r = 0.78, p = 0.001), and DHS and TD in the 30s Test (r = 0.88, p = 0.000). CONCLUSION: A 4-week high-intensity off-season training program effectively enhances both aerobic fitness and sprint endurance in U-15 female soccer players. These findings highlight the efficacy of HIIT-based training in mitigating performance losses during the off-season, enabling players to resume the season with improved conditioning. References: 1) Silva JR, Brito J, Akenhead R, Nassis GP. The Transition Period in Soccer: A Window of Opportunity. Sports Med. 2016; 46(3): 305-13.
Read CV Marco PanasciECSS Paris 2023: OP-AP23
INTRODUCTION: The development of young athletes is not only influenced by skill level and training but also by their biological maturity (Albaladejo-Saura et al., 2021; Malina, 2014). In basketball, where physical demand and technical execution are key, understanding how maturity levels affect a player’s internal load, external load, and technical behaviour (Guimarães et al., 2019; Johnson et al., 2022; Towlson et al., 2021)can provide insights that help tailoring training programs and talent identification processes. Small-sided games (SSGs) are widely recognized as an effective training modality to develop technical, tactical, and physical capacities in soccer(Arede et al., 2021; Clemente et al., 2019).. Previous literature has predominantly focused on male players or larger group formats (e.g., 4v4, 5v5). However, limited research has been dedicated to female players and, in particular, to smaller formats such as 1v1 and 2v2 competitions. This study aims to investigate these relationships by testing U14, U15, and U16 athletes in 1v1 and 2v2 game scenarios. The general aim of the scientific study is to investigate the internal and external loads experienced by female soccer players of different maturity levels during 1v1 and 2v2 small-sided games., in comparison to performance outcomes driven by technological methods or random-based approaches. METHODS: 18 female soccer players between the ages of 13 and 17 was tested. PHV categories were determined using biological maturity to classify them into different maturity groups. This approach helps to address the influence of maturation status on performance. After participating in each game scenario, players recorded their perceived exertion using the Borg scale, providing insight into subjective performance differences between the groups RESULTS: Results showed that mean and peak heart rates were generally higher in the 1v1 format as compared to the 2v2 format across all maturity groups. RPE scores corroborated the HR findings,External load metrics indicated that more mature players covered greater absolute total distances and engaged in more high-intensity sprints during both game formats. 1v1 formats showed a higher frequency of accelerations and decelerations per minute, consistent with greater changes of pace and direction required. This was especially evident in pre-mature players, who spent more effort changing direction, reflecting their developing neuromuscular control abilities. CONCLUSION: Game Format Differences show that it is Higher Intensity in 1v1, and Greater Distance in 2v2. Post-mature players demonstrate higher absolute physical outputs (e.g., distance, sprints) due to their advanced physical development. However, when normalized to body mass or HR max, the relative loads are comparable across maturity groups. This study demonstrates that 1v1 and 2v2 small-sided games impose distinct internal and external load demands on female soccer players, with significant differences observed across maturity levels.
Read CV Ximing ShangECSS Paris 2023: OP-AP23