Simulated Soccer Research Articles

Body temperature and physical performance responses are not maintained at the time of pitch-entry when typical substitute-specific match-day practices are adopted before simulated soccer match-play

ObjectivesTo profile performance and physiological responses to typical patterns of match-day activity for second-half soccer substitutes. DesignDescriptive. MethodsFollowing a warm-up, 13 male team sports players underwent ∼85min of rest, punctuated with five min rewarm-ups at ∼25, ∼50, and ∼70min, before ∼30min of simulated soccer match-play. Countermovement jump performance (jump height, peak power output), alongside 15m sprints, were assessed post-warm-up, and pre- and post-simulated match-play. Core temperature, heart rate, ratings of perceived exertion, and blood glucose and lactate concentrations were measured throughout. ResultsWarm-up-induced core temperature elevations (∼2.3%, +0.85°C; p<0.001) were maintained until after the first rewarm-up. Thereafter, core temperature was reduced from post-warm-up values until pre-simulated match-play (∼1.6%, −0.60°C; p<0.001), where values were similar to pre-warm-up (37.07±0.24°C, p=0.981). Simulated match-play increased core temperature progressively (p≤0.05) but values remained lower than post-warm-up (∼5min; p=0.002) until ∼10min into exercise. From post-warm-up to pre-simulated match-play, sprint times (∼3.9%, +0.10s, p=0.003), jump height (∼9.4%, −3.1cm; p=0.017), and peak power output (∼7.2%, −296W; p<0.001) worsened. Despite increased ratings of perceived exertion and elevated blood lactate concentrations (p≤0.05), sprint times were maintained throughout exercise, whereas peak power increased (∼7.8%, +294W; p=0.006) pre- to post-exercise. ConclusionsAt the point of simulated pitch-entry, body temperature and physical performance responses were not maintained from warm-up cessation despite typical substitute-specific match-day practices being employed in thermoneutral conditions. Evidence of performance-limiting fatigue was absent during ∼30min of simulated match-play. These data question the efficacy of practices typically implemented by substitutes before pitch-entry.

Performing the Kick During Walking for RoboCup 3D Soccer Simulation League Using Reinforcement Learning Algorithm

Nowadays, humanoid soccer serves as a benchmark for artificial intelligence and robotic problems. The factors such as the kicking speed and the number of kicks by robot soccer players are the most significant aims that the participating teams are pursued in the RoboCup 3D Soccer Simulation League. The proposed method presents a kicking strategy during walking for humanoid soccer robots. Achieving an accurate and powerful kicking while robots are moving requires a dynamic optimization of the speed and motion parameters of the robot. In this paper, a curved motion path has been designed based on the robot position relative to the ball and the goal. Ultimately, the robot will be able to kick at the goal by walking along this curve path. The speed and angle of the walking robot are set towards the ball with regard to the robots curved motion path. After the final step of the robot, the accurate and effective adjustment of these two parameters ensures that the robot is located in the ideal position to perform the perfect kick. Due to the noise and walking condition of the robot, it is essential that the speed and angle of motion to be measured more accurately. For this purpose, we use a reinforcement learning model to adjust the robots step size and so does achieve the optimal value of two abovementioned parameters. Using reinforcement learning, robot would learn to pursue an optimal policy to correctly kick towards designated points. Therefore, the proposed method is a model-free and based on dynamic programming. The experiments reveal that the proposed method has significantly improved the team overall performance and robots ability to kick. Our proposed method has been 9.32% successful on average and outperformed the UTAustinVilla agent in terms of goal-scoring time in a non-opponent simulator.

Effect of a Simulated Match on Lower Limb Neuromuscular Performance in Youth Footballers-A Two Year Longitudinal Study.

The aim of this study was to explore the effects of simulated soccer match play on neuromuscular performance in adolescent players longitudinally over a two-year period. Eleven players completed all measurements in both years of the study (1st year: age 16.0 ± 0.4 y; stature 178.8 ± 6.4 cm; mass 67.5 ± 7.8 kg; maturity-offset 2.24 ± 0.71 y). There was a significant reduction in hamstring strength after simulated match by the soccer-specific aerobic field test (SAFT90), with four out of eight parameters compromised in U16s (4.7–7.8% decrease) and six in the U17s (3.1–15.4%). In the U17s all of the concentric quadriceps strength parameters were decreased (3.7–8.6%) as well as the vastus lateralis and semitendinosus firing frequency (26.9–35.4%). In both ages leg stiffness decreased (9.2–10.2%) and reactive strength increased pre to post simulated match (U16 8.0%; U17 2.5%). A comparison of changes between age groups did not show any differences. This study demonstrates a decrease in neuromuscular performance post simulated match play in both ages but observed changes were not age dependent.

Effects of Cryotherapy and Foam Rolling Recovery Methods on Performance and Muscle Damage Indices in Young Male Soccer Players After Simulated Soccer Match

Background: Research is limited on the effectiveness of various post-soccer match recovery methods. Objectives: This study aimed to investigate the effects of active recovery methods on performance and muscle damage indices in young male soccer players. Methods: In this study, 21 male subjects (age 16.95 ± 2, height 175.29 ± 4, weight 65.99 ± 5) were selected and divided randomly into three recovery groups after a simulated soccer match. Foam roller recovery included massaging various muscle groups using a foam roller. Recovery by immersion in cold water involved immersing the body up to the neck in cold water at 15 °C. In inactive recovery, the subjects had no activity. The Yo-Yo recovery test, Sargent jump test, 20-m speed test, lactometer, and ELISA tests were used to measure the variables of aerobic power, explosive power, speed, lactate, lactate dehydrogenase, and creatinine kinase, respectively. A two-way ANOVA test with repeated measures was used to determine the differences at a confidence interval of 95%. Results: A significant difference was observed between the foam roller recovery group and the control group 24 hours after the simulated soccer match in muscle damage indices (P value &lt; 0.05). However, in the active recovery group comparison, no significant difference was observed in the performance indices (P value &lt; 0.05). Conclusions: It seems that foam rolling recovery can be used as a useful way to accelerate recovery compared to water immersion recovery through a reduction in inflammatory responses.

Exploring communication protocols and centralized critics in multi-agent deep learning

Tackling multi-agent environments where each agent has a local limited observation of the global state is a non-trivial task that often requires hand-tuned solutions. A team of agents coordinating in such scenarios must handle the complex underlying environment, while each agent only has partial knowledge about the environment. Deep reinforcement learning has been shown to achieve super-human performance in single-agent environments, and has since been adapted to the multi-agent paradigm. This paper proposes A3C3, a multi-agent deep learning algorithm, where agents are evaluated by a centralized referee during the learning phase, but remain independent from each other in actual execution. This referee’s neural network is augmented with a permutation invariance architecture to increase its scalability to large teams. A3C3 also allows agents to learn communication protocols with which agents share relevant information to their team members, allowing them to overcome their limited knowledge, and achieve coordination. A3C3 and its permutation invariant augmentation is evaluated in multiple multi-agent test-beds, which include partially-observable scenarios, swarm environments, and complex 3D soccer simulations.

External Validity of the T-SAFT90: A Soccer Simulation Including Technical and Jumping Activities.

To examinethe physiological, muscle-damage, endocrine, and immune responses to a modified soccer-simulation protocol to include technical and jumping activities characteristic of match play (the Technical Soccer-Specific Aerobic Field Test; T-SAFT90). Eighteen university players (age23 [2]y, stature175 [5]cm, body mass74 [11]kg) performed the 90-minute protocol, with acute physiological responses monitored via heart rate, ratings of perceived exertion (6-20 scale), and body mass changes. Creatine kinase, myoglobin, cortisol, and leukocyte subset concentrations were measured at baseline, immediately (0h), and 24 hours post T-SAFT90. T-SAFT90 incurred an average heart rate equivalent to 87% (5%) of maximum, 16 (2)a.u. ratings of perceived exertion, and a 1.5% (1.0%) body mass deficit. Moderate to large proliferation of leukocyte subsets (P ≤ .01; leukocytes: 6.4-fold; neutrophils: 5.5-fold; lymphocytes: 2.0-fold) and increases in cortisol (2.3-fold) were observed at 0 hours (effect size = 1.13-3.52), each returning to baseline by 24 hours (P > .45; effect size = 0.05-0.50). Myoglobin peaked immediately post T-SAFT90 (4.8-fold), whereas creatine kinase (24h: 6.0-fold) showed a delayed time course (both P ≤ .001; very large effects; effect size = 2.66 and 3.43, respectively). The magnitude and time course of the physiological, immune, endocrine, and muscle-damage markers observed during and following T-SAFT90 are similar to values reported in match-play literature, demonstrating external validity of the simulation.

Changes in Hamstring Eccentric Peak Torques and Angles of Peak Torque Following 90 Minutes of Soccer Specific Exertions

This study aimed to investigate the effects of a ball-oriented soccer match-play simulation on the hamstrings eccentric torque production. Seven male recreational athletes volunteered for this study. Participants completed 90-minutes of the ball-oriented soccer simulation interceded by a 15-minute half time interval with five successful trials of hamstrings eccentric contractions on an isokinetic dynamometer at selected time points throughout the simulation. A 2 (limb: dominant; non-dominant) × 4 (time: 0 min; 45 min; 60 min; 105 min) “split-plots” analysis of variance (SPANOVA) revealed significant reductions in hamstrings eccentric peak torques over time, while no significant change was apparent in hamstrings eccentric angles of peak torque. There was also no interaction effect of limb dominance over time for both peak torque and angles of peak torque parameters. The observed changes suggest that exertions from a ball-oriented soccer match-play simulation may have detrimental effects on the hamstrings eccentric strength parameters thus may increase risk of ACL injury. High variabilities in angles of peak torques were also observed in this study. Future exploration is warranted in order to address the extent of variabilities that may be present in larger sample sizes thus providing a better understanding of the influence of these variabilities on the muscular strength parameters of ACL injury risk. The findings suggest firstly, that fatigue from soccer-specific exertions during match-play may increase an athlete’s susceptibility to ACL injury, and secondly, that with accumulating fatigue, the nondominant limb may be equally at risk of injury as the dominant limb, contradicting previous findings from epidemiological studies.

Brief cycles of lower-limb occlusion accelerate recovery kinetics in soccer players

ABSTRACT Objective: The aim of this study was to assess the effect of intermittent vascular occlusion (IVO) on recovery following simulated soccer physical demand test in soccer players. Methods: Twelve soccer players completed the Loughborough Intermittent Shuttle Test (LIST) in two conditions placebo (PLA) and IVO followed by intermittent lower-limb occlusion. Physical performance (Squat jump: SJ, countermovement jump: CMJ, maximal voluntary contraction: MVC, and 20 m sprint: SP), muscle damage parameters (creatine kinase: CK, Lactate dehydrogenase: LDH), inflammatory parameter (C-reactive protein: CRP), and perceived muscle soreness (DOMS) were assessed before, immediately after (0 h), and 24 h, 48 h, and 72 h following the exercise. Results: Following the LIST, a decrease was observed in all Physical performance within 48 h in PLA condition (p < 0.05), compared to PLA treatment, IVO treatment attenuated the decrease of SJ and CMJ at 24 h and at 48 h and for MVC and SP within 48 h after the LIST (p < 0.05). CK and LDH levels increased within 24 h post-exercise in both conditions (p < 0.05), but with a lower level in IVO compared to PLA condition (p < 0.05). Likewise, DOMS values were significantly lower with IVO condition compared to PLA condition immediately and at 24 h after exercise. Conclusion: The results of the present study suggest that the application of IVO after simulated soccer physical demand test accelerated recovery kinetics in soccer players.

Changes in countermovement jump performance and subjective readiness-to-train scores following a simulated soccer match

The study investigated whether countermovement jump (CMJ) metrics and subjective responses to a readiness-to-train questionnaire (RTT-Q) tracked simulated match-induced acute fatigue. This was a randomized cross-over repeated measures study. Participants were assigned into one of two groups; CONTROL or LIST. The LIST group performed the Loughborough Intermittent Shuttle Run (LIST), which was designed to simulate the demands of a soccer match. The CONTROL performed light physical activity at an intensity of <65% of maximal heart rate. Each group performed three CMJ’s and completed an RTT-Q before (PRE), and again at 24 and 48 h after the LIST and/or CONTROL interventions. At 24 h there were significant differences in RTT-Q answers between the Pre and 24 h for the LIST group for questions; “Do you feel physically strong today?” and “Do you have muscle soreness today?” (p = 0.02 and 0.0008, respectively). The questions “Do you feel mentally strong today?” and “Do you have muscle soreness today?” (p = 0.02 and p = 0.0001 respectively) were the only questions that had a significant difference between Pre and 48 h for the LIST group. None of the CMJ metrics (LIST or CONTROL) changed significantly at any stage of the experiment. Although fatigue was detected by changes in the RTT-Q at 24 and 48 h after the LIST, none of the CMJ metrics changed. These findings suggest that subjective measures are more sensitive to low-level fatigue than objective measures, thus effective monitoring should include both.

Evaluation-function modeling with multi-layered perceptron for RoboCup soccer 2D simulation

In the RoboCup soccer simulation 2D league, players make a decision at each cycle in real time. The performance of a team highly depends on the agents’ decision-making process, which is composed of a action planning method and an evaluation function of the soccer field. In this work, a cooperative action planning based on the tree search is employed. Each action is evaluated by an evaluation function. We employ a multi-layered perceptron to construct an evaluation function. We examine the performance of the soccer agents when various sets of features are used as the input of the neural network. A feature vector is made of kick sequences executed by an expert team extracted from log files. To investigate the efficiency of our approach, we compare the performance of a team using an evaluation function modeled by neural networks against a team using a hand-tuned evaluation function.

Representation and Learning Methods for Situation Evaluation in RoboCup Soccer Simulation

Representation and Learning Methods for Situation Evaluation in RoboCup Soccer Simulation

Addition of Caffeine to a Carbohydrate Feeding Strategy Prior to Intermittent Exercise.

The ergogenic effect of caffeine is well established, although no investigations providing a high carbohydrate feeding strategy (pre-exercise meal=2 g/kg BM) co-ingested with caffeine exist for soccer. This investigation examines the effect of caffeine in addition to a pre-exercise carbohydrate meal and drink mid-way through a soccer simulation. Eight recreational soccer players completed an 85-minute soccer simulation followed by an exercise capacity test (Yo-yo Intermittent Endurance test level 2) on two occasions. Prior to exercise participants consumed a high carbohydrate meal, with placebo or 5 mg/kg BM-1 caffeine. No significant performance effect was identified (p=0.099) despite a 12.8% (109 m) improvement in exercise capacity following caffeine. Rates of carbohydrate and fat oxidation did not differ between conditions and nor were differences apparent for plasma glucose, fatty acids, glycerol, β-hydroxybutyrate (p>0.05). However, an increase in lactate was observed for caffeine (p=0.039). A significant condition effect on rating of perceived exertion was identified (p<0.001), with the overall mean for the protocol lowered to 11.7±0.9 au for caffeine compared to 12.8±1.3 au. Caffeine supplementation with a carbohydrate feeding strategy failed to affect metabolic and metabolite responses, although reductions in perception of exercise were observed. While a 12.8% increase in exercise capacity was noted the findings were not significant, possibly due to the small sample size.

The Effects of Low- and High-Glycemic Index Sport Nutrition Bars on Metabolism and Performance in Recreational Soccer Players.

Consumption of low-glycemic index (GI) carbohydrates (CHO) may be superior to high-GI CHO before exercise by increasing fat oxidation and decreasing carbohydrate oxidation. We compared the effects of pre-exercise feeding of a low-GI lentil-based sports nutrition bar with a high-GI bar on metabolism and performance during a simulated soccer match. Using a randomized, double-blind, counterbalanced, crossover design, participants (n = 8) consumed 1.5 g/kg available CHO from a low-GI bar (GI = 45) or high-GI bar (GI = 101) two hours before a 90 min simulated soccer match, and 0.38 g/kg body mass during a 15 min half-time break. The test involved alternating 6 min intervals of paced jogging, running, walking, and sprinting, and 3 min intervals of soccer-specific skills (timed ball dribbling, agility running, heading, kicking accuracy). Carbohydrate oxidation rate was lower during the match after consuming the low-GI compared to high-GI bar (2.17 ± 0.6 vs. 2.72 ± 0.4 g/min; p < 0.05). Participants performed better during the low-GI versus high-GI bar condition on the agility test (5.7 ± 0.4 versus 6.1 ± 0.6 s; p < 0.01) and heading (i.e., jumping height 24.7 ± 4.3 versus 22.2 ± 4.5 cm; p < 0.01) late in the soccer match (72 min). A low-GI lentil-based sports nutrition bar provides a metabolic benefit (lower carbohydrate oxidation rate) and a modest improvement in agility running and jumping height (heading) late in the test.

Read-the-game: System for skill-based visual exploratory activity assessment with a full body virtual reality soccer simulation

We present a novel virtual reality (VR) system to measure soccer players’ read-the-game ability. Read-the-game is a term that encompasses a conglomerate of visual exploratory behavioral patterns and cognitive elements required to make accurate in-game decisions. Our technological approach in the Sports Science domain focuses on the visuomotor component of targeted skill development in a VR simulation because VR is a powerful perception–action coupling training solution for visuomotor coordination due to its high sense of immersion and its psychological byproduct presence. Additionally, we analyze two critical aspects: psychological (i.e., sense of presence) and the human–computer interaction (HCI) domain (i.e., suitable input device for full-body immersion). To measure head movements related to visual explorations, the system tracks the user’s head excursions. Specifically, the engaged visual exploratory activity (VEA) during a VR simulation is measured frame-by-frame at runtime to study the behavior of players making passing decisions while experiencing pressure from rivals during in-game situations recreated with computer graphics (CG). Additionally, the sense of presence elicited by our system is measured via the Igroup Presence Questionnaire applied to beginner and amateur soccer players (n = 24). Regarding the HCI aspect, a comparison of input options reveals that a high presence can be achieved when using full body interactions that integrate head and body motions via a combination of an HMD and kinetic body tracking. During our system verification, a difference in the VEA performance is observed between beginner and amateur players. Moreover, we demonstrate the capacity of the system to measure the VEA while evoking immersive soccer in-match experiences with a portable VR setup.

Chronic Beetroot Juice Supplementation Accelerates Recovery Kinetics following Simulated Match Play in Soccer Players

Objective To assess the effect of beetroot juice (BET) on recovery kinetics of physical performance, muscle damage and perceived muscle soreness after simulated soccer match play in soccer players. Method In a randomized, double-blind, crossover design, thirteen soccer players completed the Loughborough Intermittent Shuttle Test LIST. Players received either BET or placebo (PLA) (2*150) for 7 days (3 days pre-exercise, on the day trial, and 3 days post-exercise). Physical performance (Squat jump: SJ, countermovement jump: CMJ, maximal voluntary contraction: MVC, and 20 meters sprint: SP), blood markers of muscle damage (creatine kinase: CK, Lactate dehydrogenase: LDH), inflammatory parameter (C-reactive protein: CRP) and perceived muscle soreness (DOMS) were assessed at baseline, 0 h, 24 h, 48 h and 72 h following the exercise. Results Following the LIST, a decrease was observed in CMJ, MVC and SP at 0 h, 24 h, 48 h in both conditions (p < 0.05). However, compared to PLA session, this decrease was significantly attenuated with BET for CMJ at 24 h and at 48 h and for MVC at 0 h, 24 h, 48 h and for SP at 48 h after the LIST (p < 0.05). Likewise, DOMS values were significantly lower with BET compared to PLA condition immediately and at 24 h after exercise.CK, LDH and CRP levels increased at 0 h and at 24 h post exercise in both conditions (p < 0.05), but without any significant difference between the two condition (p > 0.05). Conclusion The results of the present study suggest that chronic beetroot juice supplementation reduces post exercise perceived muscle soreness and maintain better performance during the recovery period in soccer players.

The effect of smartphones and playing video games on decision-making in soccer players: A crossover and randomised study

ABSTRACTThe objective of this study was to analyse the effect of the use of social networks in smartphones or playing video games on the passing decision-making performance in professional soccer athletes. Participants were 25 male professional soccer athletes (mean ± SD: age 23.4 ± 2.8 years). The participants performed three randomised conditions divided into three groups: control (CON), smartphone (SMA), and video game (VID). Before and after each experimental condition, the Stroop Task assessed the level of induced mental fatigue. Then, the athletes performed a simulated soccer match. A CANON® camera recorded the matches for further analysis on passing decision-making performance. A group effect was identified (p < .01) with impairment on passing decision-making performance for the SMA (p = .01, ES = 0.5) and VID (p = .01, ES = 0.5) conditions. We concluded that the use of social networks on smartphones and/or playing video games right before official soccer matches might impair the passing decision-making performance in professional soccer athletes.

Effect of cold water immersion on muscle damage indexes after simulated soccer training in young soccer players

Summary Study aim: To investigate the effect of cold water immersion (CWI) on muscle damage indexes after simulated soccer activity in young soccer players. Material and methods: Eighteen professional male soccer players were randomly divided into two groups: CWI (n = 10, age 19.3 ± 0.5, body mass index 22.2 ± 1.3) and control (n = 8, age 19.4 ± 0.8, body mass index 21.7 ± 1.5). Both groups performed a simulated 90-minute soccer-specific aerobic field test (SAFT90). Then, the CWI group subjects immersed themselves for 10 minutes in 8°C water, while the control group subjects sat passively for the same time period. Blood samples were taken before, immediately after, 10 minutes, 24 hours and 48 hours after the training session in a fasted state. Blood lactate, creatine kinase (CK) and lactate dehydrogenase (LDH) enzyme levels were measured. Results: Lactate, CK and LDH levels increased significantly after training (p &lt; 0.001). There were significant interactions between groups and subsequent measurements for CK (p = 0.0012) and LDH (p = 0.0471). There was no significant difference in lactate level between the two groups at any aforementioned time. Conclusion: It seems that CWI after simulated 90-minute soccer training can reduce the values of muscle damage indexes in soccer players.

Cooperative Localization for Multiple Soccer Agents Using Factor Graphs and Sequential Monte Carlo

This paper addresses the cooperative localization problem for a multiagent system in the framework of belief propagation. In particular, we consider the RoboCup 3D Soccer Simulation scenario, in which the networked agents are able to obtain simulated measurements of the distance and bearing to both known landmarks and teammates as well as the direction of arrival (DOA) of messages received from allies around the field. There are, however, severe communication restrictions between the agents, which limit the size and periodicity of the information that can be exchanged between them. We factorize the joint probability density function of the state of the robots conditioned on all measurements in the network in order to derive the corresponding factor graph representation of the cooperative localization problem. Then we apply the sum-product-algorithm (SPA) and introduce suitable implementations thereof using hybrid Gaussian-Mixture Model (GMM) / Sequential Monte Carlo (SMC) representations of the individual messages that are passed at each network location. Simulated results show that the cooperative estimates for position and orientation converge faster and present smaller errors when compared to the non-cooperative estimates in situations where agents do not observe landmarks for a long period.

Reflecting on side-cutting variability on ACL injury risk: A case study

This case study aims to discuss a proposal for identifying anterior cruciate ligament injury (ACL) risk by observing the variability of side cutting kinematics with respect to the development of fatigue. One participant (n=1) sustained an ACL injury while performing a side-cutting task during the latter stages of a soccer match a few months after a recorded laboratory session. Data from his laboratory session was then compared to matched samples of seventeen healthy, uninjured participants (n=17). The injured participant was found to have performed his side-cutting task with a lower deviation than mean variability right before the later stages of the second half of simulated soccer match-play. Over time, the participant performed side-cutting tasks with increased variability in sagittal plane kinematics, suggesting that compensatory actions may have been implemented to facilitate the task execution. This elevated variability may be indicative of an increased risk of ACL injury. The further prospective investigation is warranted to gain a deeper understanding of how variabilities may play a role in task execution performance with respect to injury mechanisms.

Effects of Ramadan Fasting on Recovery Following a Simulated Soccer Match in Professional Soccer Players: A Pilot Study.

Objectives: Assessing the effects of Ramadan fasting on recovery following a soccer match simulation.Methods: Eight elite soccer players (age: 21.0 ± 0.4 years) performed a modified Loughborough Intermittent Shuttle Test protocol (LISTmod) on two occasions: 1 week before (BR) and during the fourth week of Ramadan (End-R). At BR and End-R, soccer players performed squat jump, countermovement jump, maximal voluntary contraction, and 20 m sprint, and creatine kinase, uric acid, and subjective ratings (feelings scale, quality of sleep, fatigue, muscle soreness and stress) were assessed at baseline and 0, 24, 48, and 72 h following LISTmod.Results: Following LISTmod, performance in squat jump (48 and 72 h) (p < 0.05), countermovement jump (48 and 72 h), maximal voluntary contraction (0, 24, 48, and 72 h), and 20 m sprint (0 and 48 h) decreased significantly on both occasions. Decreases were higher at End-R than BR. Creatine kinase levels increased significantly at 24 and 48 h at BR and End-R (p < 0.05). Uric acid increased at 0 and 24 h only on BR. Muscle soreness increased throughout the recovery period at both occasions, with a higher level at End-R. Stress rating increased only at 0 h on End-R, while fatigue rating increased at 24 h at BR and at 0, 24, and 48 h at End-R.Conclusion: Perturbations in physical performance and subjective ratings parameters were higher at the end of Ramadan. However, the results of this study showed that Ramadan fasting did not adversely affect the recovery following soccer match simulation in professional soccer players.