Search

The aims of this study were to identify the key external and internal load variables in professional futsal through principal components analysis (PCA), and analyse the physical performance required by the players in official matches. Data were collected from 14 female players during 10 matches using WIMU PROTM. The PCA selected a total of 22 variables as key indicators of players' load. Specifically, these variables were represented by five principal components. However, a novel finding was that different components were extracted when the analysis was carried out by full match (68.83% of total variance), first half (69.81% of total variance), or second half (65.96% of total variance). Also, this study found that the players decreased their physical performance during the second half. Based on these results, this study may help optimize performance and reduce the injury risk. Performance should not be only analysed considering the full match external/internal load but also specifying by match halves. This is explained by the fact that there were variables that made up the principal components in the first half, but not in the second half or full match. Finally, coaches should adopt training strategies which deal with the decrease in physical performance during the second half. [ABSTRACT FROM AUTHOR]

The aims of this study were to 1) determine the key load indicators in professional soccer through principal component analysis (PCA); and 2) analyse the load variability of each training and match day within the microcycle considering the principal components. Data from 111 load variables were collected using tracking systems in both training and match days (MD). The results showed that 7 variables, which belonged to the first two components of the PCA, explained 80.3% of total variance. Specifically, these variables were Metabolic power, total of steps, Fourier transform (FFT) duration, deceleration distance covered (2–3 m/s2), total of running actions (12–18 km/h; 21–24 km/h), and distance covered (6–12 km/h). Regarding the analysis of the load variability of each training and match day within the microcycle, the lowest load variability was observed in −1MD. Also, a great load variability in +1MD with significant differences compared to −5MD (p<0.001; d=0.49) and −4MD (p=0.01; d=0.26) was found. This study suggests the use of the PCA in the context of team sports to reduce the large number of variables, which are daily managed by strength and conditioning coaches, in addition to the analysis of load variability of each training and match day within the microcycle. [ABSTRACT FROM AUTHOR]

This study analysed the periods in which the most demanding passages (MDP) of play occurred during professional soccer matches, considering different criterion variables and investigating the effect that the playing position had on the MDP-of-play occurrence for each criterion variable. The MDP of play were calculated based on five criterion variables: distance covered (DIS), sprinting distance (SPD), high-metabolic load distance (HMLD), and the total of high-intensity accelerations and decelerations (ACCHIGH and DECHIGH). The results showed that the first period of the match (0ʹ-15ʹ) was the interval with the highest frequency (i.e., the greatest % of cases) in which the players achieved the MDP of play for all the variables (DIS= 38.9%; SPD= 28.4%; HMLD= 37.7%; ACCHIGH= 54.3%; DECHIGH= 48.8%). The playing position had no significant effect on MDP-of-play occurrence in any variable (likelihood ratio, LR= 15.88–32.05; p > 0.05; effect size, ES= 0.01–0.04), except for the DIS covered (LR= 32.05; p= 0.04; ES= 0.05), in which the most frequent MDP for the full backs occurred within the second period of the match (15ʹ-30ʹ). In conclusion, the first periods of the matches usually elicited the MDP of play and these periods need to be trained to prevent injuries and optimize performance. [ABSTRACT FROM AUTHOR]

The aims of this study were to examine the periods in which the maximum speed actions occurred during elite soccer matches and analyse these actions considering the effect of playing position and different contextual variables. Performance-related variables (VMAX: maximum speed; Vo: starting speed; SPD: sprinting distance; ACCMAX: maximum acceleration; DECMAX: maximum deceleration) and sprint-related contextual variables (trajectory, ball possession, role, field area in which the action occurred) from each maximum speed action were collected. The first 15 minutes of each match half elicited most maximum speed actions (44.6% of cases), regardless of playing position (likelihood ratio, LR=13.95; p=0.95). However, playing position had a significant effect on the role of the action (Chi-Squared, χ2=50.68; p=0.001) and the field area in which the sprint occurred (χ2=26.54; p=0.001). Regarding the effect of different contextual variables on the sprint-related performance variables, no significant effect from any contextual variable on ACCMAX, DECMAX or Vo was found (p > 0.05). Nevertheless, the contextual variables had a significant effect on SPD (from ball possession: sprints without ball > sprints with ball; trajectory: non-linear sprints > linear sprints; role: offensive sprints > defensive sprints) and VMAX (from ball possession: sprints without ball > sprints with ball; playing position: midfielders < other positions). [ABSTRACT FROM AUTHOR]

The aims of this research were to analyse the effect that different playing positions, passage durations and starting status had on the most demanding passages (MDP) of play in professional football matches. Players were categorized by positions and the MDP of distance (DIS), high-speed running distance (HSRD) and sprinting distance (SPD) were analysed for four passage durations (1, 3, 5 and 10 minutes). The results indicated that DIS (p < 0.001), HSRD (p < 0.001) and SPD (p < 0.001) covered per minute decreased as the passage durations increased for all positions. Regarding the playing position, it had a significant effect on the DIS (p < 0.001), HSRD (p < 0.001) and SPD (p < 0.001) covered. In addition, although the results reported that the starting status had no significant effect on the DIS (p = 0.36) covered, it had a statistically significant effect on the HSRD (p = 0.01) and SPD (p < 0.001) covered. Coaching and medical departments should consider the impact that these variables have on players' performance when designing training drills aimed at preparing the player for the competitive demands. [ABSTRACT FROM AUTHOR]

Objectives: To determine the effect of a stretching program performed in the workplace on the hamstring muscle extensibility and sagittal spinal posture of adult women. Material and methods: Fifty-eight adult women volunteers (mean age of 44.23 ± 8.87 years) from a private fruit and vegetable company were randomly assigned to experimental (n=27) or control (n=31) groups. The experimental group performed three exercises of hamstrings stretching of 20 seconds per exercise, three sessions a week for a period of 12 weeks. The control group did not participate in any hamstring stretching program. Hamstring flexibility was evaluated through the passive straight leg raise test and toe-touch test, performed both before and after the stretching program. Thoracic and lumbar curvatures and pelvic inclination were measured in relaxed standing and toe-touch test with a Spinal Mouse. Results: Significant increases (p < 0.01) in toe-touch score and straight leg raise angle (in both legs) were found in the experimental group during post-test, while the control group showed a non-significant decrease for both toe-touch score and straight leg raise test. A significant decrease in thoracic curve and significant increase in pelvic inclination were found in the toe-touch test for the experimental group (p <0.05). However, no significant changes were found in standing posture for any group. Conclusions: Hamstring stretching exercises performed in the working place are effective for increasing hamstring muscle extensibility. This increase generates a more aligned thoracic curve and more anterior pelvic inclination when maximal trunk flexion is performed. [ABSTRACT FROM AUTHOR]