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- Within- and between-mesocycle variations of well-being measures in top elite male soccer players: a longitudinal studyPublication . Oliveira, Rafael; Ceylan, Halil İbrahim; Brito, João; Martins, Alexandre; Nalha, Matilde; Mendes, Bruno; Clemente, Filipe ManuelBackground: The aims of this study were to describe the variations of training monotony (TM), training strain (TS), and acute:chronic workload ratio (ACWR) through Hooper Index categories (fatigue, stress, DOMS, and sleep quality) and to compare those variations between player status and player positions. Methods: Seventeen male professional soccer players participated in this study. Considering player status, participants were divided in nine starters and eight non-starters. Additionally, participants were divided by playing positions: three wide defenders, four central defenders, three wide midfielders, four central midfielders, and three strikers. They were followed during 40-week in-season period. TM, TS, and ACWR were calculated for each HI category, respectively. Data were grouped in 10 mesocycles for further analysis. Results: Results showed variations across the mesocycles. In general, starters showed higher values for TM, TS, and ACWR calculations than non-starters, although there were some exceptions. Regarding player positions, significant differences were found in stress between wide defenders vs central midfielders for TM (p = 0.033, ES = 5.16), central defenders vs wide defenders for ACWR (p = 0.044, ES = 4.95), and in sleep between wide defenders and strikers for TM (p = 0.015, ES = 5.80). Conclusions: This study revealed that an analysis of players’ well-being parameters according to player status and positions can provide clear information to the coaches and their staff to complement the tasks of training monitoring.
- Does elite European match-play affect salivary immunoglobulin- a and cortisol in soccer players? The influence of playing status and match outcomePublication . Morgans, R.; Oliveira, Rafael; Rhodes, D.; Orme, P.; Ceylan, H. I.; González-Fernández, F. T.; Linán-González, A.; Moreira, A.Introduction: The aims of this study were to: a) investigate salivary immunoglobulin A (s-IgA) and cortisol (s-Cort) responses to nine competitive fixtures in starting and non- starting soccer players; and b) compare s-IgA and s Cort responses of starters and non-starters considering match outcome. Methods: Saliva from 19 male outfield players from an elite soccer team (mean ± SD, age 26 ± 4 years; weight 80.5 ± 8.1 kg; height 1.83 ± 0.07 m; body-fat 10.8% ± 0.7%) was collected. Saliva samples were taken on the day before each match (MD-1), 60-min before kick-off (MDpre), 30-min post-match (MDpost), and 72-h post-match (MD+3). There were five wins, one draw and three losses. Results: The mean s-IgA value was found to be significantly lower at MD+3 compared to MDpre and MDpost. s-Cort was significantly higher at MDpost compared to MD-1 and MDpre. When compared to MDpre, a statistically significant decrease in s-Cort was observed at MD+3 compared to MDpost. Starters displayed higher s-Cort values across the nine matches. There was a significant group-by-time interaction for s-Cort. There was a significant increase in s-Cort levels at MDpost compared to MD-1 and from MDpre to MDpost in starting players. At MDpost, starters had significantly higher s-Cort values. s-IgA values of starting and non- starting players following successful and unsuccessful matches did not reveal a significant difference. However, similar analysis of s-Cort in successful matches showed a significant difference between starters and non starters. s-IgA values at MD-1, MDpre, MDpost and MD+3 in starters and non starters following successful and unsuccessful matches revealed significant differences at MDpre and MDpost in starters, respectively. Furthermore, s-Cort values at MD-1, MDpre, MDpost and MD+3 in starters and non-starters in successful and unsuccessful matches revealed significant differences at MD+3 in starting players.Discussion: The present study suggests that in elite level soccer players, both starting status and match outcome influence s-IgA and s-Cort responses, particularly starters. Specifically, s-IgA was lower for starters before and after the match following successful outcomes. Moreover, higher s-Cort values were found before the match while lower values occurred after the match for starters in successful matches.
- Acute: chronic workload ratio and training monotony variations over the season in professional soccer: a systematic reviewPublication . Rico-González, Markel; González Fernández, Francisco Tomás; Oliveira, Rafael; Clemente, Filipe ManuelAcute: chronic workload ratio (ACWR) and training monotony have been criticized as injury risk predictors. Therefore, the use of intensity measures should be oriented to understand the variations of intensity across the season. The aim of this systematic review is to summarize the main evidence about the ACWR and training monotony variations over the season in professional soccer players. The search was made in PubMed, SPORTDiscus, and FECYT according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. From the 225 studies initially identified, 27 were fully reviewed, and their outcome measures were extracted and analyzed. Existing literature revealed a variety of designs, ACWR and training monotony ranges, variables assessed and durations of the studies. Overall, the range values for ACWR were 0.4–3.39 AU, while those focused on monotony were 0.49–5.7 AU. Regarding ACWR, the ratios located around 0.85–1.25 could predict lower risk values and ratios around ≥1.50 could predict higher risk values. On the contrary, with respect to training monotony, the ratios are approximately between 0.5 and 2.00 (low values in the preseason and low competition weeks and high values when soccer players are in highly scheduled competition weeks). Nevertheless, ACWR and training monotony methods should be addressed and considered based on their real value before using this indicator to reduce injury risk. In fact, the data did not conclusively define injured and non-injured players. For this reason, utilizing standardized approaches will allow for more precise conclusions about professional soccer players.
- Comparisons and correlations between the anthropometric profile and physical performance of professional female and male soccer players: Individualities that should be considered in trainingPublication . Schons, Pedro; Birk Preissler, Artur Avelino; Oliveira, Rafael; Brito, João Paulo; Clemente, Filipe Manuel; Droescher de Vargas, Guilherme; Moraes Klein, Lucas; Kruel, Luiz Fernando MartinsFor male soccer players, the anthropometric profile and physical performance is already known but in women it is not well documented, the knowledge of these differences can qualify the training. Therefore, the aim of this study was two fold: (i) to compare the anthropometric profile and physical fitness of Brazilian professional female and male soccer players; and (ii) analyze the relationships between anthropometric and physical fitness measures per sex. A cross-sectional study including 92 professional soccer players 44 women and 48 men was conducted. After one week of the end of the pre-season, the players from four different teams were assessed to anthropometric profile assessments and physical per formance tests (e.g., jumping, linear sprint, change-of-direction and aerobic based test). Comparisons, correlation, and effect size analysis were performed between groups. Apart from the age and change-of-direction test, all other anthropo metric and physical performance variables were significant different between women and men. Men were significantly faster than women in the 20 m linear sprint test (8.87%; p < .001; d=2.382). The sum of skinfolds was correlated with some physical performance variables; however, body mass and body height were corrected with physical perform ance only for female soccer players. Thus, men performed better than women for most physical tests and presents dif ferences in the anthropometric profile. Finally, coaches should consider that the anthropometric and performance profile are correlated differently between female and male soccer players. Thus, coaches should consider gender-specific para meters to create goals about the anthropometric and physical performance profile of players.
- Effects of plyometric jump training on soccer player’s balance: a systematic review and meta-analysis of randomized-controlled trialsPublication . Clemente, Filipe Manuel; Ramirez-Campillo, Rodrigo; Castillo, Daniel; Raya-Gonzalez, Javier; Rico-Gonzalez, Markel; Oliveira, Rafael; Roseman, Thomas; Knechtle, BeatPlyometric jump training (PJT) can be used for improving balance through bilateral and unilateral jump-landing drills. Since the increased number of articles testing the effects of PJT on dynamic and static balance, it is relevant to summarize the evidence and determine the effects across different original articles. This systematic review with meta-analysis was conducted to assess the effects of PJT programs on dynamic and static balance in soccer players. The data sources utilized were Cochrane, Medline (PubMed), SPORTDiscus, and Web of Science. (i) Soccer players of any age or sex without injury, illness, or other clinical conditions; (ii) PJT-based programs restricted to a minimum of three weeks (duration); (iii) passive or active control groups; (iv) pre-post interventions values of dynamic and/or static balance; (v) randomized-controlled trials; and (vi) peerreviewed original full-text studies written in English, Portuguese, and/or Spanish. The database search initially identified 803 titles. From those, eight articles were eligible for the systematic review and meta-analysis. The results showed no significant differences between PJT and active controls in dynamic anterior, postero-medial, or postero-lateral balance for both left and right legs (p > 0.05). Additionally, no significant differences were found between PJT and active controls in terms of static balance (p = 0.495). The current evidence suggests that PJT has no significant advantage over active control groups in terms of dynamic or static balance.
- Players´ performance during the worst-case scenarios in professional soccer matches: a systematic reviewPublication . Rico-González, Markel; Oliveira, Rafael; Vieira, Luiz; Pino-Ortega, José; Clemente, Filipe ManuelSince the analysis of worst-case scenarios (WCS) has been increasing knowledge about match demands and possible impacts for the training process, it seems important to summarize the evidence to provide useful information for the soccer community. Thus, the purpose of this systematic review was to summarize the evidence about WCS in professional soccer. A systematic review of PubMed, SPORTDiscus, and FECYT (Web of Sciences, CCC, DIIDW, KJD, MEDLINE, RSCI, and SCIELO) was performed according to the guidelines for performing systematic reviews in sport science. From the 85 studies initially identified, 12 were fully reviewed, and their outcome measures were extracted and analyzed. There was an inverse relationship between the duration of WCS windows and running output during match play. Occurrences of WCS during soccer matches were also position-dependent across studies, at least, when analyzing performance with the total distance covered variable, although different outputs were identified between women and men players. Future research should consider analyzing the impact of contextual variables (match status, team formation, and match location) on peak match values and the weight of these moderators.
- Are physiological, physical, wellness and load decisive markers of starting players? A case study from a professional male soccer teamPublication . Oliveira, Rafael; Canário-Lemos, Rui; Morgans, Ryland; Rafael-Moreira, Tiago; Vilaça-Alves, José; Brito, JoãoThe study aim was to compare physiological, physical, accumulated wellness and load markers within a European professional soccer team between starters and non-starters. Ten starters (age: 25.1 ± 2.2 years; experience: 7.3 ± 2.3 years) and eight non starters (age: 26.1 ± 4.6; years’ experience: 8.3 ± 4.1 years) participated in the study. The study was conducted across 20 weeks where 75 training sessions and 15 matches occurred. Wellness (fatigue, quality of sleep, muscle soreness, stress and mood) and load (rating of perceived exertion (RPE), accelerations, decelerations, high-speed running and sprinting) measures were observed. Physiological evaluation consisted of a 1200 m maximum effort shuttle test while physical capacity assessment included isokinetic strength, jump ability and balance tests. Isokinetic tests were used to assess peak torque of both legs (extension and flexion at 60◦ /s and 180◦ /s), single squat jump and single hop jump were utilized to assess jump ability and Y-balance tests were employed to examine balance. Starters presented significantly higher values for peak torque extension of the non-dominant leg compared to non-starters (p = 0.038, effect size (ES) = 0.996), while non-starters showed higher values for both Y-balance postero-medial and postero lateral (p = 0.009, ES = −1.309 and p = 0.021, ES = −1.133, respectively). Accumulated duration and RPE were lower for non-starters than starters (p ≤ 0.001, ES = 1.268, and p = 0.022, ES = 1.123, respectively). The physiological and physical tests conducted in this study do not seem to determine the starting status of players, considering that only one test revealed significantly higher values for starters. Despite the lower training and match duration for non-starters, this showed that it is possible to accumulate identical load while managing wellness regardless of starting status.
- Physical Fitness Variations between Those Playing More and Those Playing Less Time in the Matches: A Case-Control Study in Youth Soccer PlayersPublication . Silva, Ana Filipa; Clemente, Filipe Manuel; Leão, César; Oliveira, Rafael; Badicu, Georgian; Nobari, Hadi; Poli, Luca; Carvutto, Roberto; Greco, Gianpiero; Fischetti, Francesco; Cataldi, StefaniaThe purpose of this study was (i) to compare two groups (players with more vs. less match play time) regarding body composition, vertical and horizontal jumping performance, and aerobic capacity; and (ii) to test the relationships between physical fitness and play time. This study followed a case-control design in which the outcome was playtime, and the causal attribute was physical fitness. Sixty-six youth male soccer players from under-16 (n = 21), under-17 (n = 19), under-18 (n = 12), and under-19 (n = 14) age groups were monitored for match play time during five months of observation. Inclusion criteria consisted of (1) no absence of more than a week due to injury or other conditions during the five months of observation and (2) physical assessments having been done simultaneously with those of the other players (at the beginning of the season). The exclusion criteria were (1) not participating in one week or more of training sessions, and (2) not participating in the physical fitness assessments. At the beginning of the season, players were assessed for anthropometry (height, body mass, skinfolds), countermovement jump, triple hop bilateral and unilateral jump, and aerobic capacity using the Yo-Yo Intermittent Recovery Test, level 2 (YYIRT). The group that played more time had significantly greater YYIRT results (+28.2%; p = 0.009; Cohen’s d = 0.664). No other significant differences were found between those who played more and fewer minutes. Moderate and significant linear positive correlations were found between YYIRT and play time in the under-19 group (r = 0.423; p = 0.031) and overall (r = 0.401; p < 0.001). In the case of the under-17 group, moderate and significant linear positive correlations were found between TSA and play time (r = 0.473; p = 0.041). This suggests that aerobic and anaerobic capacity is related to play time while jumping performance and fat mass seem not to play an essential role in play time.
- Comparisons and associations among anthropometric indices of first and second division and assistant soccer refereesPublication . Samarein, Meysam Rostamzadeh; Samanipour, Mohammad Hossein; Asjodi, Foad; Shokati, Pooya; Fallahi, Zanyar; Brownlee, Thomas E.; Brito, João; Bragazzi, Nicola Luigi; Oliveira, RafaelIntroduction: Body composition is an important predictor of performance and a key component of health and physical fitness. Therefore, the purposes of this study were to compare soccer referees of the first and second divisions and field assistant referees from Iran and to analyze associations of a body shape index (ABSI), body adiposity index (BAI), abdominal volume index (AVI), body roundness index (BRI), conicity index (ConI), and body mass index (BMI) with body fat percentage (%BF). Methods: A total of 270 male soccer referees from the first (n = 124) and second (n = 72) divisions and assistant referees (n = 74) participated in this study. Skinfold thickness (measured at the chest, biceps, triceps, subscapular, abdominal, iliac crest, and front thigh), height, weight, hip circumference, and waist circumference were assessed to evaluate waist-to-height ratio (WHtR), %BF, and also ABSI, BRI, BAI, ConI, and AVI according to the ISAK protocol. Results: The main results indicated differences in WHR, WHtR, ABSI, BRI, AVI, ConI, and BF% with the assistant referees presenting higher values (p < 0.05). When considering the backward selection model, there were some associations with %BF in each group, specifically BMI, BAI, and ABSI in the first division; BMI, WHR, and ABSI in the second division; and BMI in the assistant referee group (all p < 0.05). Discussion: The present study did not confirm the hypothesis that the first-division referees presented better body composition-related variables than the second division or assistant referees. Instead, it showed that the assistant referees that participated in both divisions showed a tendency to higher values which suggests that the level of division is not a major factor when analyzing body composition.
- Assessing the agreement between a global navigation satellite system and an optical-tracking system for measuring total, high-speed running, and sprint distances in official soccer matchesPublication . Makar, Piotr; Silva, Ana Filipa; Oliveira, Rafael; Janusiak, Marcin; Parus, Przemysław; Smoter, Małgorzata; Clemente, Filipe ManuelThis study aimed to compare the agreement of total distance (TD), high-speed running (HSR) distance, and sprint distance during 16 official soccer matches between a global navigation satellite system (GNSS) and an optical-tracking system. A total of 24 male soccer players, who are actively participating in the Polish Ekstraklasa professional league, were included in the analysis conducted during official competitions. The players were systematically monitored using Catapult GNSS (10-Hz, S7) and Tracab optical-tracking system (25-Hz, ChyronHego). TD, HSR distance, sprint distance, HSR count (HSRC), and sprint count (SC) were collected. The data were extracted in 5-min epochs. A statistical approach was employed to visually examine the relationship between the systems based on the same measure. Additionally, R2 was utilized as a metric to quantify the proportion of variance accounted for by a variable. To assess agreement, Bland–Altman plots were visually inspected. The data from both systems were compared using the estimates derived from the intraclass correlation (ICC) test and Pearson product–moment correlation. Finally, a paired t-test was employed to compare the measurements obtained from both systems. The interaction between Catapult and Tracab systems revealed an R2 of 0.717 for TD, 0.512 for HSR distance, 0.647 for sprint distance, 0.349 for HSRC, and 0.261 for SC. The ICC values for absolute agreement between the systems were excellent for TD (ICC = 0.974) and good for HSR distance (ICC = 0.766), sprint distance (ICC = 0.822). The ICC values were not good for HSRCs (ICC = 0.659) and SCs (ICC = 0.640). t-test revealed significant differences between Catapult and Tracab for TD (p < 0.001; d = −0.084), HSR distance (p < 0.001; d = −0.481), sprint distance (p < 0.001; d = −0.513), HSRC (p < 0.001; d = −0.558), and SC (p < 0.001; d = −0.334). Although both systems present acceptable agreement in TD, they may not be perfectly interchangeable, which sports scientists and coaches must consider when using them.