Goring during bullfights represents a penetrating trauma with a high risk of muscular, vascular, and vital injuries. Despite its frequency and severity, limited information is available on the immediate physiological response of the bullfighter at the moment of trauma. This case report describes the heart rate of a professional bullfighter who was gored during a bullfight, underwent surgery, and returned to fight the next bull. During the first fight, the bullfighter suffered a penetrating goring wound to the inner side of the lower third of his right thigh and a fracture of the ninth rib with intercostal rupture. Upon standing, he experienced a marked drop in heart rate and a feeling of loss of consciousness, possibly associated with vasovagal presyncope. He was transferred to the infirmary in hemodynamically stable condition. He was given local anesthesia, followed by surgical exploration, cleaning, and layered closure of the wound. After surgery, the bullfighter experienced a gradual increase in heart rate upon standing, possibly due to postural changes and postoperative sympathetic activation. He then returned to the bullring to resume activity. This case report highlights a possible vasovagal response to penetrating trauma, which may be relevant for trauma care, as a vasovagal or parasympathetic-predominant autonomic response could influence early clinical assessment.

This study investigated the influence of defensive player positioning on the external and internal loads experienced during small-sided transition games (TGs) and the subsequent effects on sprint and jump performance. Twenty male youth players (age 15.7 ± 0.2 years; height 175.3 ± 7.5 cm; mass 67.1 ± 6.8 kg) completed two 7-min bouts, with 2 minutes of passive recovery, of 2 vs. 2 TGs under three defensive configurations: defenders in front of attackers (TGFront), behind attackers (TGBehind), and parallel to attackers (TGParallel). During each TG, we recorded total distance covered (DC), distance covered in running (18.0-20.9 km · h-1), high-intensity running (21.0-23.9 km · h-1), and sprinting (> 24.0 km · h-1), peak speed, mechanical load, and the number of accelerations and decelerations > 1.0 m · s-2 and > 2.5 m · s-2. Ratings of perceived exertion (RPE) were also collected. Sprint (30 m) and countermovement jump (CMJ) tests were administered immediately before and after each session. The results showed that TGParallel and TGBehind elicited significantly greater DC, distances in running, high-intensity running, and sprinting zones, mechanical load, accelerations > 2.5 m · s-2, and RPE compared to TGFront (p < 0.05). Moreover, TGParallel produced higher DC in high-intensity running, sprinting, mechanical load, and accelerations > 2.5 m · s-2 than TGBehind (p < 0.05). No TG format induced significant changes in sprint or CMJ performance (pre- vs. post-test, p > 0.05). These findings demonstrate that positioning defenders behind or parallel to attackers increases both external and internal loads across running, high-intensity, and sprinting zones during TGs, without compromising subsequent sprint or jump performance.

Observing fluctuations in blood sugar during competitive events yields significant data regarding the metabolic demands placed upon athletes. This investigation sought to delineate the glycemic characteristics of top-level female soccer players throughout official matches. A total of ten elite women’s soccer players (age: 27.2 ± 3.8 years; BMI: 21.7 ± 1.5 kg/m2) from the same team had their interstitial glucose (iG) levels recorded via continuous glucose monitoring (CGM) throughout two distinct match cycles. External physical workloads were captured using global positioning systems. The athletes were categorized by their playing role, as starters or bench players, and the observation window was partitioned into four segments: night-time, pre-match, match, and post-match. Data indicated a between-subject coefficient of variation (CV) of 13% and a within-subject CV of 17%. Starting players showed elevated variability (16% between; 20% within) relative to bench players (9% and 13%). While temporal factors remained stable, playing status influenced iG significantly (F = 5.44, p = 0.006, ηp2 = 0.44). Specifically, starters experienced higher iG during competition versus night (+26.5 mg/dL, p = 0.001), pre-match (+22.2 mg/dL, p = 0.002), and post-match (+25.9 mg/dL, p = 0.004). These findings suggest that CGM may assist staff in developing tailored nutritional interventions, given the wide range of individual responses found in this unexplored field.

Objective: The primary aim of this study was to compare eccentric knee flexion isokinetic performance at two commonly used angular velocities (60°·s−1 and 180°·s−1) between dominant and non-dominant limbs in healthy professional soccer players through the analysis of peak torque, mean peak torque, angle of peak torque, total work, and rate-of-torque-development-related variables. The secondary aim was to describe concentric knee extension and knee flexion strength variables assessed at 60°·s−1. Methods: Forty male professional soccer players performed concentric knee flexion–extension testing at 60°·s−1 and eccentric knee flexion testing at 60°·s−1 and 180°·s−1 using an isokinetic dynamometer. Peak torque (PT), mean peak torque (MPT), angle of peak torque (APT), total work (TW), and hamstrings: quadriceps ratios (H:Q ratios) were analyzed for dominant and non-dominant limbs. Inter-limb differences, repetition effects, and reliability indices were calculated. Results: No significant inter-limb differences were observed for most variables (trivial–small effect sizes), except for higher eccentric TW at 180°·s−1 in the dominant limb (p = 0.009). Eccentric PT and MPT decreased at higher velocities in both dominant (p = 0.002 and p < 0.001, respectively) and non-dominant (p = 0.008 and p < 0.001, respectively) limbs, while APT shifted toward more flexed knee angles (p < 0.001). Reliability was good to excellent (ICC = 0.81–0.87), with low measurement error. Conclusion: Eccentric knee flexion assessment at 60°·s−1 and 180°·s−1 angular velocities provided different results in PT, MPT, and APT for the same group of players, supporting the use of more than one eccentric test for obtaining information about these variables in elite soccer.

Background and Objectives: This study compared the effects of two posterior-chain strength training strategies on eccentric hamstring strength, jump and sprint performance, and hamstring injury incidence in elite youth soccer players. Materials and Methods: Twenty-three players were randomly allocated to either a Nordic Hamstring Exercise Group (NHEG; n = 11) or a Deadlift + Leg Curl Slides Group (D + LCSG; n = 12). Both groups completed a 9-week in-season resistance training program consisting of one strength-oriented session (MD-4) and one power-oriented session (MD-2) per week, in addition to regular soccer training. Pre- and post-intervention assessments included eccentric hamstring strength (NordBord), countermovement jump (CMJ), and 10 m and 30 m linear sprint performance. Results: Eccentric hamstring strength increased significantly only in the NHEG (p ≤ 0.05), though this improvement did not transfer to enhancements in jump or sprint performance (p > 0.05). No significant changes were observed in the D + LCSG for any variable (p > 0.05), and no between-group differences were found across all performance outcomes. During the 12-week monitoring period, one hamstring injury was recorded, occurring in the NHEG. Conclusions: These findings suggest that, while the NHE elicited greater exercise-specific eccentric strength gains, neither posterior-chain strategy produced improvements in sprint or jump performance. However, given the small sample size and low number of injury events, these trends cannot be attributed with certainty to the implemented protocols, and both programs reported a low incidence of hamstring injuries per 1000 h of exposure with no statistically protective effect associated with the use of the NHE.

This study aimed to compare the running activity of full−time players when the team made three or fewer substitutions versus when more than three substitutions were made. An observational study was conducted on one professional football team from the Swiss Super League during the 2021–2022 season. Matches were classified into two groups: Group A (≤3 substitutions) and Group B (>3 substitutions). Running activity was assessed using GPS technology, measuring total distance covered, sprinting distance, and acceleration/deceleration patterns. Despite a significantly higher number of substitutions in Group B (4.42 ± 0.51 vs. 2.8 ± 0.42, p < 0.01), no differences were observed between groups for all parameters analyzed (p > 0.05). Both groups exhibited significantly higher running performance during the first half compared to the second half (p < 0.01), except for distance covered >25.2 km·h−1, which remained unchanged (p > 0.05). No differences in second half running performance were found between groups (p > 0.05). The increase from three to five substitutions did not significantly alter the external load of full−time players. Running performance declined in the second half regardless of the number of substitutions made. These findings suggest that the new substitution rule does not influence the physical performance of players who complete the entire match.

The aim of this study was to analyze the effects of a 7-week combined strength and power training program on body composition, aerobic capacity, strength, sprint, and agility in elite youth soccer players. Twenty-one players, divided into age groups (U14 and U16), participated in this study. In addition to four training sessions per week (plus matches), the two groups completed a strength training session on Match Day 4 (MD-4) and a power training session on Match Day 2 (MD-2). Before and after the intervention, various tests were conducted, including skinfold measurements, submaximal intermittent shuttle run, eccentric hamstring strength (EHS), countermovement jump (CMJ), single-leg jump (SLJ), sprint test with split times at 10 and 30 m, agility t-test, push-ups, and pull-ups. Our results indicate that a seven-week program of combined strength training led to significant improvements in body composition, EHS, jump performance, and pull-up tests for both groups of players (p < 0.05). Moreover, the U14 group also demonstrated an improvement in the agility test (p < 0.01). The U14 group experienced more substantial gains than the U16 group in agility and push-up performance (p < 0.05). The sprint performance remained unchanged for both groups (p > 0.05), suggesting that specific training is required to improve this quality.

This study investigated differences in running performance between starters and substitutes during their first 15 min of match play in professional football. The investigation was designed as a retrospective observational study. A time–motion analysis was conducted on one professional football team from the Swiss Challenge League during the 2023–2024 season. The first 15 min of players’ match participation were analyzed and divided into three 5 min periods. Running performance variables included total distance covered (TDC), high-speed running (HSR; 19.8–25.2 km·h−1), and sprint distance (>25.2 km·h−1) using GPS technology. Statistical analyses were performed using paired t-tests and repeated-measures ANOVA with Bonferroni post hoc corrections. Starters covered significantly greater TDC than substitutes over the 15 min period (p = 0.002), driven by higher values in the 5–10 min and 10–15 min epochs (p = 0.01 and p < 0.001, respectively). No between-group differences were observed for HSR and sprint distance. Within-group analyses revealed a significant decline in TDC during the 10–15 min epoch compared with earlier intervals for both starters and substitutes (p < 0.001 and p = 0.02, respectively). Substitutes also exhibited a reduction in distance covered at HSR after the initial 0–5 min period (p = 0.02). Starters face higher TDC demands than substitutes in the opening 15 min, although HSR and sprint distance remain stable. The results indicate that starters covered greater TDC than substitutes during the first 15 min of play; however, no significant differences were found in HSR and sprint distance between the two conditions.

Soccer players who are non-starters typically experience reduced match loads, which can hinder their physical fitness and match readiness over time. This study aimed to investigate the running demands accumulated during top-up sessions in comparison to soccer matches. Twenty-six outfield soccer players from an elite Portuguese soccer team participated in this study. The following running variables were recorded: total distance (TD), running (14.4 to 19.7 km · h-1), high-speed running (HSR: 19.8 to 25.1 km · h-1), sprinting (≥ 25.2 km · h-1) distances, number of sprints (counts), number of accelerations (ACC; 2-3 m · s-2 and > 3 m · s-2), decelerations (DEC; 2-3 m · s-2 and > 3 m · s-2), and player load. A linear mixed-effects model was used to examine differences between top-up sessions and matches. Overall, non-starters accumulated lower running load during top-up sessions than matches for most of the variables analyzed, but in particular TD (p < 0.001; ES range 2.46 to 3.74), running (p < 0.001; ES range 2.93 to 3.90), HSR (p < 0.001; ES range 2.21 to 3.47), sprints events (p < 0.001; ES range 1.16 to 2.76), ACC > 3 m · s-2 (p < 0.005; ES range 0.98 to 1.37), DEC > 3 m · s-2 (p < 0.001; ES range 1.91 to 2.66), and player load (p < 0.001; ES range 2.34 to 3.23). Therefore, non-starters accumulated less than half of the total match distance for most of the running metrics during top-up sessions. These findings suggest that compensatory training should be designed to more closely replicate match demands, with particular attention to high-intensity demands, such as HSR and sprints.

This study investigated the adaptations induced by a 7-week training protocol combining strength and power training with regular soccer training in young elite soccer players, considering their maturity level. Thirty-five participants were categorized into three training groups according to their maturation status. They were classified based on their relative age and peak height velocity (PHV) as: Pre-PHV, Mid-PHV, and Post-PHV. Each group engaged in a 7-week program, combining their regular soccer training with two resistance sessions per week (one strength and one power session). Before and after the training program, the following tests were conducted: eccentric hamstring strength using the Nordic Hamstring Exercise (NHE), countermovement jump (CMJ), sprint with split times at 10 and 30 m, and Change of Direction and Acceleration Test (CODAT). The Pre-PHV group exhibited significant improvements in sprint performance (p < 0.02), while the Mid-PHV and Post-PHV groups showed enhanced performance in CODAT (p = 0.01 and p = 0.05, respectively). Notably, the Post-PHV group displayed improvements in the NHE (p < 0.05), but also experienced a decline in sprint performance (p < 0.01). The training protocol produced substantial enhancements in 10 and 30 m sprint times for the Pre-PHV and Mid-PHV groups relative to the Post-PHV group (p < 0.02), while the Post-PHV group achieved greater advancements in NHE compared to the Pre-PHV group (p < 0.01). No significant differences were found between Pre-PHV and Mid-PHV groups across all assessed parameters (p > 0.01). These findings demonstrated that the same strength training program led to different adaptations depending on the participants’ maturation status; therefore, this aspect should be carefully considered when designing training programs for young soccer players.

Futsal is a sport that has been on the rise in recent years. It is an intermittent high -intensity team sport played in small side with high physical demand. The main purpose of this study was to analyse and determinate the relationship between body composition and performance markers such a vertical jump, sprint, change of direction, power outcomes and intermittent performance in 1 st division female futsal players. Eleven 1 st division players participated in this study (N=11; 21,55 +/- 4,32 years; 162,09 +/- 5,56 cm; 60,17 +/- 8,05 kg) Results showed that body composition and performance are different according their tactical position. Although, body composition is correlated with sprint and power outcomes. CMJ is correlated with 10, 20 meters sprint and change of direction as well as VIFT is correlated with 20 meters sprint.

Background: Soccer is a game in constant evolution and the intensity of play is increasing. Nutrition can play a role in the physical performance of elite players, maintaining their health and facilitating recovery. It is important to cover players’ energy demands, and low energy availability may therefore result in impaired performance. This study aimed to evaluate alterations in body composition to determine the effects of a nutritional program led by a sport nutritionist. Methods: A group of 88 elite soccer players from a Serie A club in Italy (44 males aged 26.5 ± 3.0 years and 44 females aged 27.1 ± 5.2 years) were enrolled. To evaluate changes in body composition, bioimpedance and anthropometric measurements were obtained following the protocol of the International Society for the Advancement of Kinanthropometry (ISAK). Results: Compared with females, males had more muscle mass and less fat mass in both seasons evaluated. Comparing the first and last seasons, the male soccer players showed increased muscle mass and decreased fat mass while the female soccer players only showed decreased fat mass. Conclusions: The presence of a specialist sport nutritionist on the staff of professional soccer clubs could be important to ensure energy availability and evaluate body composition during the season.

BackgroundFlywheel resistance training has become more integrated within resistance training programs in a variety of sports due to the neuromuscular, strength, and task-specific enhancements reported with this training.ObjectiveThis paper aimed to present the consensus reached by internationally recognized experts during a meeting on current definitions and guidelines for the implementation of flywheel resistance training technology in sports.MethodsNineteen experts from different countries took part in the consensus process; 16 of them were present at the consensus meeting (18 May 2023) while three submitted their recommendations by e-mail. Prior to the meeting, evidence summaries were developed relating to areas of priority. This paper discusses the available evidence and consensus process from which recommendations were made regarding the appropriate use of flywheel resistance training technology in sports. The process to gain consensus had five steps: (1) performing a systematic review of systematic reviews, (2) updating the most recent umbrella review published on this topic, (3) first round discussion among a sample of the research group included in this consensus statement, (4) selection of research group members-process of the consensus meeting and formulation of the recommendations, and (5) the consensus process. The systematic analysis of the literature was performed to select the most up-to-date review papers available on the topic, which resulted in nine articles; their methodological quality was assessed according to AMSTAR 2 (Assessing the Methodological Quality of Systematic Review 2) and GRADE (Grading Recommendations Assessment Development and Evaluation). Statements and recommendations scoring 7-9 were considered appropriate.ResultsThe recommendations were based on the evidence summary and researchers' expertise; the consensus statement included three statements and seven recommendations for the use of flywheel resistance training technology. These statements and recommendations were anonymously voted on and qualitatively analyzed. The three statements reported a score ranging from 8.1 to 8.8, and therefore, all statements included in this consensus were considered appropriate. The recommendations (1-7) had a score ranging from 7.7 to 8.6, and therefore, all recommendations were considered appropriate.ConclusionsBecause of the consensus achieved among the experts in this project, it is suggested that practitioners and researchers should adopt the guidelines reported in this consensus statement regarding the use of flywheel resistance technology in sports.

The aim of this study was to analyze the differences in internal and external load during Soccer-7 and Soccer-11, comparing positional requirements and neuromuscular fatigue in both modalities. Twenty-four young soccer players were monitored in Soccer-7 and Soccer-11 matches using global positioning systems. Total distance covered (TD), distance covered at high speed (HSR), distance covered at very high speed (VHSR), peak speed, accelerations (Acc) and decelerations (Dec) and rate of perceived exertion (RPE) were recorded differentiating between central backs (CB), midfielders (MF), external players (EX) and forwards (FW). Neuromuscular fatigue were assessed using a jump test. During Soccer-11, players showed significantly higher TD, HSR and VHSR, with low Acc and greater RPE compared with Soccer-7. During Soccer-11, all positions recorded significantly greater TD, distance at HSR and at VHSR than Soccer-7. In terms of playing position, CB, MF and FW achieved significantly higher Peak Speed during Soccer-1, but there was no difference for EX. During Soccer-7 all positions performed significantly higher numbers of Acc. Although the Soccer-7 modality is considered an optimal format for the development of young soccer players, there is a significant difference in match running activity for all playing positions with respect to the Soccer-11 format.

The aims of this study were to determine the effect of different compositions in transition games (TGs) on the load of soccer players and to evaluate their performance in physical tests. Using a GPS system, 18 players were monitored during: 3vs2, 2vs1 and 1vs1. Distance covered (DC), DC 18-20.9 km.h(-1), 21-23.9 km.h(-1), > 24 km.h(-1), peak speed, accelerations (Acc) and decelerations (Dec) > 1.0 m.s(-2) and > 2.5 m.s(-2) and rate of perceived exertion (RPE) were recorded. Before and after each TG, countermovement-jump (CMJ), 15- (S-15) and 30 m (S-30) speed tests were assessed. TG(3vs2) showed greater DC and Dec > 1.0 m.s(-2) than TG(2vs1), and DC, DC 18.0- 23.9 km.h(-1), Acc > 1.0 m.s-(2) and Dec > 2.5 m.s(-2) than TG(1vs1) (p < 0.01). TG(2vs1) achieved higher DC, DC 18.0-23.9 km.h(-1), and Acc > 2.5 m.s(-2) (p < 0.01) but lower peak speed (p = 0.02) and RPE (p = 0.02) than TG(1vs1). Post-intervention, TG(1vs1) showed lower CMJ and higher S15 (p = 0.02), while TG(3vs2), showed improvements in CMJ (p < 0.01). The three tasks showed large variations for DC > 24 km.h(-1), Acc > 1.0 m.s(-2), Dec > 1.0 m.s(-2) and Dec > 2.5 m.s(-2). The load of TGs is sensitive to their player composition.

The aim of this study was to compare the running demands of transition games (TGs) and official matches, analysing their requirements according to the performance of each position. An observational design was used to examine the activity of 20 soccer players during official matches and TGs. GPS technology was used to monitor the total distance covered (DC), distance at speeds between 14–17.9 km·h−1, 18–21 km·h−1, and above 21 km·h−1, peak speed, accelerations and decelerations above 2.5 m·s−2, and Player Load for both activities. All players were assigned to groups: centre-backs (CBs), fullbacks (FBs), defensive midfielders (DMFs), offensive midfielders (OMFs), wide midfielders (WMFs) and strikers (Ss). TGs showed greater total DC, DC 14–17.9 km·h−1, DC 18–21 km·h−1, DC >21 km·h−1, accelerations and decelerations >2.5 m·s−2, and Player Load (p < 0.01). CBs, FBs and Ss showed more DC, DC 14–17.9 km·h−1, DC 18–21 km·h−1, DC >21 km·h−1, accelerations and decelerations >2.5 m·s−2 and Player Load in TGs (p < 0.01). In the midfielder positions, transition game players showed greater DC 18–21 km·h−1, DC >21 km·h−1, accelerations and decelerations >2.5 m·s−2 than in matches (p < 0.05). DMFs showed higher total DC (p < 0.05) and WMFs greater DC and DC 14–17.9 km·h−1 (p < 0.01) in these drills. During transition games CBs showed greater DC 14–17.9 km·h−1 than FBs, and greater DC than Ss (p < 0.05). FBs performed more decelerations >2.5 m·s−2 than DMFs and OMFs (p < 0.05). TGs produced a homogenized load in soccer players, independent of their position, which exceeded the external load of official matches.

This study aimed to provide reference values for anthropometric characteristics of elite male and female soccer players, considering a group of individuals from the general population as controls. The anthropometric profiles of 357 elite soccer players [184 males (age 24.3 ± 4.3 y) and 173 females (age 25.2 ± 5.1 y)] participating in the first Italian league (Serie A) and 363 subjects from the general population [188 males (age 24.2 ± 4.8 y) and 175 females (age 25.0 ± 5.1 y)] were measured according to the guidelines of the International Society for the Advancement of Kinanthropometry (ISAK). Reference percentiles for stature, body mass, circumferences, eight skinfolds (biceps, triceps, subscapular, suprailiac, supraspinal, abdominal, front thigh, and calf), breadths, and somatotype were calculated and stratified by player position and sex. No difference (p > 0.05) was found in age between the two groups. Soccer players showed lower values for the sum of the eight ISAK skinfolds than individuals from the general population of the same sex. This suggests lower adipose tissue, as indicated by a lower endomorphic component. The somatotype was endomorphic mesomorph and mesomorphic endomorph for the male and female individuals from the general population, respectively. The male soccer players were ectomorphic mesomorphs, while the females were balanced mesomorphs, defining a sport-specific morphology. This study provides sex- and role-specific anthropometric standards for elite soccer players. Raw anthropometric reference values may be useful for evaluating body composition without using any predictive equations or assumptions.

El fútbol sala es un deporte en crecimiento en los últimos años. Es un deporte colectivo intermitente de alta intensidad jugado en un espacio reducido con altas demandas físicas. El objetivo principal de este estudio fue analizar la composición corporal, el rendimiento en acciones de alta intensidad como el salto vertical, el sprint, el cambio de dirección, la estimación de potencia y el rendimiento intermitente en jugadoras de fútbol sala de 1ª división y relacionarlas entre sí. En este estudio participaron once jugadoras de fútbol sala de primera división española (N=11; 21,55 ± 4,32 años; 162,09 ± 5,56 cm; 60,17 ± 8,05 kg). Los resultados revelan que la composición corporal y el rendimiento de las jugadoras varía en función de su posición específica. Además, la composición corporal está relacionada con el sprint y la estimación de potencia. El CMJ se relaciona con el sprint en 10 y 20 metros y con el cambio de dirección, así como la VIFT se relaciona con el sprint en 20 metros.

To ensure both optimal health and performances, monitoring physiological and psychological states is of main importance for athletes. It is well known that monitoring heart rate variability and using validated questionnaires is useful for monitoring both the health and training status of athletes of different sports. Motorsports such as rally require high levels of physical and mental preparation thus information about psychophysiological status of rally athletes is fundamental. The aim of this study was to assess the autonomic regulation, stress, recovery conditions of one driver and one co-driver competing at the Italian National Rally Championship during their competition period. Heart rate variability parameters, acute recovery and stress states were assessed the day before, during the two days of race and the day following the races. Results showed that driver and co-driver had a sharp decrease of mean RR intervals, root mean square of successive differences between normal heartbeats, and standard deviation of the N-N interval during race days, while the stress index showed the inverse trend, and this behaviour was clearly visible in the Poincaré plots and power spectrum density graphs. The acute recovery and stress states questionnaire showed significant differences in recovery and stress scoring for the driver but not for the co-driver, although the trends were similar. This study describes the psychophysiological demands of a rally competition period suggesting that a daily evaluation of heart rate variability, recovery, stress states is useful for monitoring health status in rally athletes and could be implemented to make decision about training and recovery strategies.

Evidence of the relationship between physical activity and gut microbiota composition is steadily increasing. The purpose of the study is to compare the gut microbiota composition of a group of elite male soccer players with a group of subjects with different physical activity levels. Cross-sectional studies were performed on 91 healthy young males, in detail: 17 elite soccer players (23.7 ± 4.2 yrs, BMI 23.2 ± 1.2 kg/m2); 14 with high levels of physical training (24.5 ± 5.6 yrs, BMI 22.7 ± 0.8 kg/m2); 23 with moderate levels of physical training (29.3 ± 3.9 yrs, BMI 22.5 ± 0.8 kg/m2); and 37 healthy men without exercise habits (28.1 ± 5.9 yrs, BMI 22.4 ± 1.0 kg/m2). Relative microbiota composition was determined by analyzing DNA extracted from stool samples. The quality and quantity of extracted DNA were assessed using a Qubit Fluorometer. Differences between subjects' populations were analyzed using a one-way ANOVA, and Bonferroni's post-hoc test was employed to identify localized effects. Elite soccer players and subjects with high physical activity levels showed a significantly higher prevalence of the nine microbiota populations analyzed than subjects with moderate physical training or who were sedentary. No differences were found in the Firmicutes to Bacteroidetes ratio among the different study populations. This study reports the gut microbiota parameters of elite footballers for the first time. In addition, it brings new insights into the effects of different levels of physical activity on the composition of the gut microbiota.