Entists and coaches to improve the understanding of the physical demands of this sport. This study investigated the physical and physiological demands of elite men's rugby sevens, with special reference to the temporal patterns of fatigue during match play. Nine players, 4 backs and 5 forwards (age 25.1 ± 3.1 years) participated during 2 “Roma 7s” international tournaments (2010 and 2011). All the players were at the professional level in the highest Italian rugby union, and 5 of these players also competed at the international level. During the matches (n = 15), the players were filmed to assess game performance. Global positioning system, heart rate (HR), and blood lactate (BLa) concentration data were measured and analyzed. The mean total distance covered throughout matches was 1,221 ± 118 m (first half = 643 ± 70 m and second half = 578 ± 77 m; with a decrease of 11.2%, p > 0.05, Effect Size [ES] = 0.29). The players achieved 88.3 ± 4.2 and 87.7 ± 3.4% of the HRmax during the first and second halves, respectively. The BLa for the first and second halves was 3.9 ± 0.9 and 11.2 ± 1.4 mmol·L−1, respectively. The decreases in performance occurred consistently in the final 3 minutes of the matches (−40.5% in the distance covered per minute). The difference found in relation to the playing position, although not statistically significant (p = 0.11), showed a large ES (η2 = 0.20), suggesting possible practical implications. These results demonstrate that rugby sevens is a demanding sport that places stress on both the anaerobic glycolytic and aerobic oxidative energy systems. Strength and conditioning programs designed to train these energy pathways may prevent fatigue-induced reductions in physical performance....

The performance of a soccer team depends on many factors such as decision-making, cognitive and physical skills, and dynamic ever-changing space–time interactions between teammate and opponents in relation to the ball. Seventy (n = 70) matches of the Italian SERIE A season 2013–2014 were investigated to analyze the mean performance of 360 players in terms of physical (physical efficiency index; PEI) and technical–tactical (technical efficiency index; TEI) standpoints. Using a semiautomatic video analysis system that has incorporated new parameters able to measure technical–tactical and physical efficiency (Patent IB2010/002593, 2011-ISA), the correlation between these new variables and how much it relates to the likelihood of winning were verified. Correlations between TEI and PEI were significant (n = 140, r = .60, p < .001), and TEI showed a higher likelihood of winning than PEI factors (p < .0001 vs. .0001, CI 95% [1.64, 3.00] vs. [1.28, 2.07]). Higher TEI and TEI + PEI differences between the teams were associated with a greater likelihood of winning, but PEI differences were not. Key performance indicators and this performance assessment method might be useful to better understand what determines winning and to assist the overall training process and match management.

Relative Age Effects (RAEs) appear largely throughout youth soccer. However, little is known about how RAEs at youth levels can impact transition at senior levels. Accordingly, this study aimed to : (a) provide further test of RAEs by exploring the birth quarter (BQ) distribution of 2,030 Italian players born from 1975 to 2001 who have played in any of the Youth National Italian Soccer Teams ; and (b) investigate how RAEs influence future career outcomes, by exploring the BQ distribution of players who completed the transition from youth squads to the Senior National Team (n = 182) Chi-square statistics revealed significantly skewed BQ distributions for all Youth squads (P values <0.0001), and for the cohort of players who completed the transition (P = 0.003). In contrast, results from the Odds Ratios highlighted how BQ4s were more likely to transition from youth-to-senior compared to BQ1s . Results showed BQ1s remained overrepresented at senior level due to a residual bias effect. Whereas BQ4s who were able to overcome selection processes at youth levels recorded the highest likelihood of competing at senior levels. Involving players’ career trajectories in RAEs studies is needed to understand how RAEs impacts career outcomes of early selected players.

The purpose of the study was to examine the differences in bilateral deficit (BLD) at different loadings during the half-squat jump (SJ) and horizontal countermovement jump (HCMJ) to determine if there is a relationship with linear sprint or change of direction (COD). The second goal was to check if fast players were more powerful in SJ and HCMJ than slow players in bilateral performance (BP). Twenty-seven male youth soccer players participated in the study. Players were divided in two groups, faster and slower, according to their sprint performance (10 and 40 m). BLD average power with body weight (BW) and 25%BW were significantly higher than 50%BW (p < 0.01). BLD during HCMJ was significantly higher than BLD during SJ with BW, 25%BW and 50%BW (p < 0.01). There were no statistical relationships between BLD and sprint or COD performance (p > 0.05). Fast players showed significantly higher SJ power with all the different loads and HCMJ than slow players (p < 0.01), and fast players lost more time executing COD-90° than slow players (p < 0.01). There were no statistical differences between fast and slow players in BLD. BLD seems to be dependent on motor task, contraction type and load and could not be a proper measure to estimate sprint and COD performance. Faster players are confirmed to be more powerful players than slow players, and decrements in COD could be a key benchmark to identify deficit between linear and COD performance.

The purpose of this investigation was to determine if there were different trends in physical fatigue observed in 3 different sets, of 7 trials each, in repeated sprint training, performed in 3 different modes: straight sprinting over 30 m, shuttle sprinting over 15 + 15 m, and sprinting over 30 m with changes of direction. Recovery time among trials in the sets was administered according to the 1:5 exercise to rest ratio. The sets were performed on 3 different days, with at least 48 hours between each set. The study involved 17 trained male soccer players (height, 177.33 ± 6.21 cm; body mass, 71.63 ± 9.58 kg; body mass index, 23 ± 2.39 kg·m; age, 21.94 ± 3.58 years). To compare the different values of the time recorded, an index of fatigue was used. Significant differences among trials within each set (repeated measures analysis of variance; p < 0.05) and between the sets (factorial analysis of variance; p < 0.001) were found. Significant correlations between each test and countermovement jump and stiffness values recorded pre exercise were found (p < 0.05). Significant differences between countermovement jump and stiffness values recorded pre and post exercise were also found (p < 0.05). This study suggests that training sessions aimed at increasing the capacity of repeated sprint ability in nonlinear and multidirectional sprints (shuttle and change of direction), which might imply a different number of trials within the set or different exercise to rest ratios from the ones usually adopted for straight sprinting, to induce similar trends of fatigue. As practical applications, the estimated numbers of necessary trials in the different sets and the possible exercise to rest ratios, resulting from mathematical modeling, are provided for each investigated sprinting mode.

The main purpose of this study was to compare the effects on strength and muscle power of a training program based on two different modalities of whole-body electrostimulation (WB-EMS) with respect to a resistance-training program aimed at improving dynamic strength. Twenty-two subjects participated in this study: Thirteen male (age 25.2±2.8 years; height 1.78±0.1 m; body mass 72.8±6.4 kg; body fat 11.6±2.3%) and nine female (age 28.2±3.5 years; height 1.63±0.05 m; body mass 56.8±7.6 kg; body fat 19.1±4.7%). Participants were randomly assigned to three groups that underwent three different 6-week training programs: two modalities of WB-EMS, based on different electrical parameters (experimental), and circuit training with overloads (control). Force-velocity curves were calculated for each participant before and after treatment. All groups improved their level of strength and muscle power (paired sample t-Test, p1) with a similar magnitude. No significant differences were observed between groups (two-way 2×3 Anova, p>0.05) at the end of the experimentation. This study suggests that WB-EMS might be considered as a valid and faster alternative – or an important complementary procedure – to a traditional overload-based resistance-training program for the development of the DS.