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- Can an Incremental Step Test Be Used for Maximal Lactate Steady State Determination in Swimming? Clues for PracticePublication . Espada, Mário C.; Alves, Francisco B.; Curto, Dália; Ferreira, Cátia C.; SANTOS, FERNANDO JORGE LOURENÇO DOS; Pessôa Filho, Dalton; Reis, Joana F.We aimed to compare the velocity, physiological responses, and stroke mechanics between the lactate parameters determined in an incremental step test (IST) and maximal lactate steady state (MLSS). Fourteen well-trained male swimmers (16.8 ± 2.8 years) were timed for 400 m and 200 m (T200). Afterwards, a 7 × 200-m front-crawl IST was performed. Swimming velocity, heart rate (HR), blood lactate concentration (BLC), stroke mechanics, and rate of perceived exertion (RPE) were measured throughout the IST and in the 30-min continuous test (CT) bouts for MLSS determination. Swimming velocities at lactate threshold determined with log-log methodology (1.34 ± 0.06 m·s −1 ) and Dmax methodology (1.40 ± 0.06 m·s −1 ); and also, the velocity at BLC of 4 mmol·L −1 (1.36 ± 0.07) were not significantly different from MLSSv, however, Bland–Altman analysis showed wide limits of agreement and the concordance correlation coefficient showed poor strength of agreement between the aforementioned parameters which precludes their interchangeable use. Stroke mechanics, HR, RPE, and BLC in MLSSv were not significantly different from the fourth repetition of IST (85% of T200), which by itself can provide useful support to daily practice of well-trained swimmers. Nevertheless, the determination of MLSSv, based on a CT, remains more accurate for exercise evaluation and prescription.
- Physiological and physical effect on U-12 and U-15 football players, with the manipulation of task constraints: field size and goalkeeper in small-sided games of 4x4 playersPublication . SANTOS, FERNANDO JORGE LOURENÇO DOS; Figueiredo, Teresa; Ferreira, Cátia; Espada, MárioOur study aimed to verify whether the task constraints manipulation has different effects according to age group. Another objective was to verify the physiological and physical responses in the different formats of small-sided games (SSG). Each team in the SSGs was composed of 4 players (4x4). The participants in the research were young football players U-12 (n=8) and U-15 (n=8), affiliated with a club certified as a training entity, and competing, respectively, in the 7 and 9-a-side regional football championships and the national championship of Portugal. The internal and external load data was collected in 5 formats of SSGs with three field sizes and in 2 used goalkeepers. We used the WIMU PROTM inertial device for data collection. The registration of the internal charge, using heart rate (HR), was performed with the use by the players of Garmin bands, which send the data to WIMU PROTM devices, through of Ant+ technology. The variance analysis (ANOVA) was used to verify the differences between SSGs and the effect size was determined by calculating partial eta-square . Comparisons between the two age groups were evaluated using standardized differences with combined variance(Cohen’s d). The results show that the manipulation of the playing areas and the use of goalkeepers participation promoted different effects in the two age groups in terms of distance, explosive distance, accelerations/decelerations and maximum sprint. As for the comparison between SSGs we found differences in the level of external load (distance, accelerations/ decelerations and maximum sprint). At the level of internal load, the effects were more evident with field areas above 100m2. We can conclude that the task constraints manipulation, playing area and goalkeeper participation, promote different physical and physiological responses, and the coach should consider this fact, as well as the effects promoted in the age groups.
- Influence of different 1v1 small-sided game conditions in internal and external load of U-15 and U-12 soccer playersPublication . SANTOS, FERNANDO JORGE LOURENÇO DOS; Ferreira, Cátia Caldeira; Figueiredo, Teresa Palmira; Espada, Mário CunhaIntroduction. Soccer is a complex team sport, in which moments of 1v1 during the game may decide the outcome. Despite this evidence, studies on this particularity are scarce, particularly involving young players. Aim of Study. The purpose of this study was to evaluate variations of internal and external loads in U-15 and U-12 soccer players associated to different smallsided game (SSG) conditions, in the 1v1 context. Material and Methods. Eight male soccer players participated in the study, integrating two groups, U-15 (n = 4) and U-12 (n = 4), monitored in different SSG models (2 minutes duration / 3 minutes interval rest, different pitch size SSG1 = 5 × 10 m; SSG2 = 10 × 15 m; SSG3 = 15 × 20 m). Soccer players carried GPS devices (WIMU PROTM, RealTrack System, Almería, Spain) operating at a sampling frequency of 10 Hz. The Mann–Whitney U test was used to compare groups in each SSG and the Kruskal–FWallis test was applied to compare the different SSGs. The significance level was adopted at p < 0.05. Results. Differences between the groups were observed mostly in HRmean and HR95-max. The distance covered (different between the groups, SSG1 197.7 ± ± 14.0 vs 162.3 ± 9.0 and SSG3 261.4 ± 10.6 vs 217.1 ± 27.4, respectively, for U-15 and U-12) and maximal velocity always increased with the increase of the pitch size. Explosive distance and accelerations were also different between the groups in SSG1 and SSG2, respectively. Differences throughout the SSGs were mainly recorded in terms of external load. Conclusions. This research suggests that the implemented 1v1 SSG model is relevant from the internal and external load perspective. Nevertheless, the internal and external loads in U-15 and U-12 soccer players present differences and specificities, which should be considered in exercise prescription and individualized evaluation of young soccer players.
- ANALYSIS OF OFFENSIVE AND DEFENSIVE ACTIONS OF YOUNG SOCCER GOALKEEPERSPublication . Santos, João; Sousa, Paulo Malico; Pinheiro, Valter; SANTOS, FERNANDO JORGE LOURENÇO DOSPurpose. The study aimed to investigate the defensive and offensive technical tactical actions of elite young football goalkeepers. Methods. The goalkeepers who participated in our study (n = 3; mean age: 16.6 years) had 8 years of experience in the position, were Portuguese, and competed in the Portuguese National Championship U-17. Thirty championship games were observed. The observational instruments used were constructed and validated for the investigation, and the technicaltactical actions were coded with the Lince® software. The data were processed through a descriptive analysis, by using the Microsoft Excel® computer program. Results. Defensive actions with most occurrences were goal defence (25.33 ± 8.14), deviation to punch (13.67 ± 12.5), with 2 hands (45.66 ± 21.38), and in zone 1 (50.33 ± 34.81). Offensive actions started more frequently with delayed pass (38.33 ± 28.01), for zone 1 (28.7 ± 20.60). The goalkeepers executed goal kick most frequently (17.33 ± 14.29), followed by short hand replacement (16.67 ± 12.06) and short pass (14.33 ± 10.02). The preferred pass zone was 9 (17.33 ± 10.26), and actions sought to initiate positional attack (86 ± 61.02). Conclusions. In the defensive process, the goalkeepers’ actions are mostly focused on the objective of goal defence; in the offensive process, technical actions with the hands and feet are important in the participation in positional attack construction.
- Physiological Responses During High-Intensity Interval Training in Young SwimmersPublication . Almeida, Tiago André Freire; Pessôa Filho, Dalton; Espada, Mário; Reis, Joana Filipa; Sancassani, Andrei; Massini, Danilo Alexandre; SANTOS, FERNANDO JORGE LOURENÇO DOS; Alves, Francisco BesoneThis study analyzed whether 100- and 200-m interval training (IT) in swimming differed regarding temporal, perceptual, and physiological responses. The IT was performed at maximal aerobic velocity (MAV) until exhaustion and time spent near to maximalVO2 peak oxygen uptake (⩒O2peak), total time limit (tLim), peak blood lactate [La−] peak, ⩒O2 kinetics (⩒O2K), and rate of perceived exertion (RPE) were compared between protocols. Twelve swimmers (seven males 16.1 ± 1.1 and five females 14.2 ± 1 years) completed a discontinuous incremental step test for the second ventilatory threshold (VT2), ⩒O2peak, and MAV assessment. The swimmers subsequently completed two IT protocols at MAV with 100- and 200-m bouts to determine the maximal ⩒O2 (peak-⩒O2) and time spent ≥VT2, 90, and 95% of ⩒O2peak for the entire protocols (IT100 and IT200) and during the first 800-m of each protocol (IT8x100 and IT4x200). A portable apparatus (K4b2) sampled gas exchange through a snorkel and an underwater led signal controlled the velocity. RPE was also recorded. The Peak-⩒O2 attained during IT8x100 and IT4x200 (57.3 ± 4.9 vs. 57.2 ± 4.6 ml·kg−1·min−1) were not different between protocols (p = 0.98) nor to ⩒O2peak (59.2 ± 4.2 ml·kg−1·min−1, p = 0.37). The time constant of ⩒O2K (24.9 ± 8.4 vs. 25.1 ± 6.3-s, p = 0.67) and [La−] peak (7.9 ± 3.4 and 8.7 ± 1.5 mmol·L−1, p = 0.15) also did not differ between IT100 and IT200. The time spent ≥VT2, 90, and 95%⩒O2peak were also not different between IT8x100 and IT4x200 (p = 0.93, 0.63, and 1.00, respectively). The RPE for IT8x100 was lower than that for IT4x200 (7.62 ± 2 vs. 9.5 ± 0.7, p = 0.01). Both protocols are considered suitable for aerobic power enhancement, since ⩒O2peak was attained with similar ⩒O2K and sustained with no differences in tLim. However, the fact that only the RPE differed between the IT protocols suggested that coaches should consider that nx100-m/15-s is perceived as less difficult to perform compared with nx200-m/30-s for the first 800-m when managing the best strategy to be implemented for aerobic power training.
- Mixed Method Research on Football Coaches’ Competitive BehaviorPublication . Rodrigues, José; Rodrigues, Filipe; Rescende, Rui; Espada, Mário; SANTOS, FERNANDO JORGE LOURENÇO DOSObjective: The purpose of this study was to present the reliability of three validated measures, namely the System of Analysis of Instruction in Competition, the Questionnaire on Coach Instructional Behavior Expectations, and the Questionnaire on Coach Instructional Behavior Perception that could be used in a mix-method approach. Methods: Three instruments underwent a robust process of construct and reliability analysis. Inter− and intra-observer reliability was tested for the observational instrument using Cohen’s k-agreement measure. Reliability values above 0.85 were considered as a good agreement between and within observers. To verify the internal consistency of the questionnaires, the correlation coefficients were considered. Results: The results related to intra-observer and inter-observer reliability showed that intra-observer reliability k-agreement values ranged between 0.912 and 1 for observer 1, and 0.82 and 1 for observer 2. For inter-observer reliability, k-agreement values ranged between 0.885 and 1 between observers. Thus, values for reliability are above acceptable. The correlation coefficient values recorded for the questionnaires on instruction expectations in the competitive moment were above 0.82 and significant (p < 0.05), and for the questionnaire on instruction perception in competition above 0.88 and significant (p < 0.05). The pilot study showed some divergent results across expectations, behavior during competition, and perception about the instruction behavior. Conclusion: The observational system and the expectations and perceptions questionnaires, used in a complementary way, can be considered as a mix-method approach for studies aiming to examine coaches’ competitive behavior.
- Training Load in Different Age Category Soccer Players and Relationship to Different Pitch Size Small-Sided GamesPublication . JORGE LOURENÇO DOS SANTOS, FERNANDO; Figueiredo, Teresa; Pessôa Filho, Dalton; Verardi, Carlos; Macedo, Anderson; Ferreira, Cátia; Espada, MárioThis study sought to evaluate the training load in different age category soccer players associated with distinct pitch size small-sided games (SSGs). Twenty-four soccer players (eight in each age category: U-12, U-15, and U-23) performed three consecutive 4 vs. 4 ball possession SSGs (SSG1: 16 × 24 m; SSG2: 20 × 30 m; and SSG3: 24 × 36 m) all with 3 min duration and 3 min rest. Subjects carried ultra-wideband-based position-tracking system devices (WIMU PRO, RealTrack System). Total distance covered increased from SSG1 to SSG3 in all age categories and predominantly in running speeds below 12 km·h−1. Moreover, distance covered in 12–18 km·h−1 running speed was different in all performed SSGs and age categories. Residual or null values were observed at 18–21 km·h−1 or above running speed, namely in U-12, the only age category where metabolic power and high metabolic load distance differences occurred throughout the performed SSGs. Edwards’ TRIMP differences between age categories was only observed in SSG2 (U-12 < U-15). The design of SSGs must consider that the training load of the players differs according to their age category and metabolic assessment should be considered in parallel to external load evaluation in SSGs. Wearable technology represents a fundamental support in soccer.
- Relation of coaches’ expectations with instruction and behavior of athletesPublication . SANTOS, FERNANDO JORGE LOURENÇO DOS; Louro, Hugo; Espada, Mário; Figueiredo, Teresa; Lopes, Hélder; Rodrigues, JoséThis study aims to identify the expectations of the coaches on the instruction and behavior of athletes. The second objective is to correlate the expectations of the coaches with the instruction behavior of coaches and with the behavior of athletes in competition. Aiming to achieve these purpose four coaches of youth soccer teams that competed in the national championships in Portugal were studied. We applied observation systems SAIC and SOCAC to encode behaviors of coach's instruction and the behavior of athletes in competition, respectively. To data collection on expectations, the coaches responded to the Questionnaire about Expectations of Instruction and Behavior of Athletes in Competition. The results show that there is short relation between the coach's expectations and what actually happens in competition regarding the instruction behavior and the behavior of athletes.
- Effects of Pitch Size and Goalkeeper Participation on Physical Load Measures during Small-Sided Games in Sub-Elite Professional Soccer PlayersPublication . SANTOS, FERNANDO JORGE LOURENÇO DOS; Verardi, Carlos; Moraes, Mayra Grava de; Pessôa Filho, Dalton; Macedo, Anderson G.; Figueiredo, Teresa P.; Ferreira, Cátia C.; Borba, Ricardo P.; Espada, MárioThis study sought to examine the variations of internal and external load measures in soccer players when performing different types of 4 vs. 4 small-sided games (SSGs). Ten U-23 professional and sub-elite soccer players, eight outfield players (age: 20.1 ± 1.5 years old; height: 1.83 ± 0.04 m; total body mass: 76.1 ± 3.6 kg) and two goalkeepers (GK) (age: 20.5 ± 2.1 years old; height: 1.91 ± 0.04 m; total body mass: 77.0 ± 1.4 kg) participated in the study. Five SSGs were performed with 3 min duration and 3 min rest interval. SSG1, SSG2 and SSG4 aimed for ball possession play, while in SSG3 and SSG5, two GK were added, defending regular-size goals. The pitch size changed from SSG1 (16 × 24 m) to SSG2 and SSG3 (both 20 × 30 m) and SSG4 and SSG5 (both 24 × 36 m). All players were monitored using WIMU Pro device during the tasks. Anova One-Way and the post hoc Tukey honestly significant difference were used for analysis of statistically significant differences (p < 0.05) and effect sizes were determined by calculating partial eta-squared. The framework was associated with relevant but steady state internal load fatigue and induce a considerable external load stimulus. GK participation in SSGs should be carefully considered as it seems to have a greater impact on physical load measures when compared to the pitch size manipulation.