Correlation between Match Performance and Field Tests in Professional Soccer Players

Do Different Playing Formats and Aerobic Capacity Influence Variances in Psychophysiological Demands and Technical Performance in Small-Sided Games? A Study among Under-17 Male Soccer Players

This study aimed to: (i) analyze the variations in psychophysiological demands (mean heart rate, meanHR; rate of perceived exertion, RPE) and technical performance (umber of successful and unsuccessful passes, and occurrences of ball loss) between 2v2 and 4v4 small-sided games (SSGs) formats, and (ii) examine the relationships of aerobic capacity measured in Yo-Yo Intermittent Recovery Test (YYIRT) on psychophysiological and technical performance during SSGs. This study used a cross-sectional design with repeated measures, where the same players participated in both 2v2 and 4v4 formats across two training sessions per format. Twenty-four talent/developmental male youth soccer players, aged 16.6 ± 0.5 years. The meanHR, measured through heart rate sensors, the RPE, assessed using the CR6-20 scale, and the number of successful and unsuccessful passes, along with occurrences of ball loss, recorded using an ad hoc observational tool, were evaluated in each repetition. Players during the 2v2 format had significantly greater mean HR (+4.1%; p < 0.001; d = 2.258), RPE (+12.2%; p < 0.001; d = 2.258), successful passes (+22.2%; p = 0.006; d = 0.884), unsuccessful passes (+62.5%; p < 0.001; d = 1.197) and lost balls (+111.1%; p < 0.001; d = 2.085) than 4v4 format. The YYIRT was significantly and largely correlated with unsuccessful passes (r = 0.502; p = 0.012) and lost balls (r = 0.421; p = 0.041) in 2v2 format. In conclusion, this study suggests that engaging in 2v2 activities constitutes a more intense form of practice, significantly enhancing individual participation in technical aspects. Moreover, aerobic capacity may influence the smaller formats of play and how players perform key technical actions. Therefore, coaches must consider this to ensure the necessary performance in such games.

Testing in Intermittent Sports-Importance for Training and Performance Optimization in Adult Athletes

ABSTRACT

Performance in intermittent sports relies on the interplay between multiple physiological systems determining the capacity to perform short explosive efforts as well as repeated intense actions with limited recovery over the course of an entire game. Testing should reflect these demands to allow for sport- and position-specific capacity analyses that eventually may translate into optimized training and improved performance. This may include individual load management and optimized training prescription, intensity targeting for specific positions or individual athletes, as well as benchmarking for monitoring of training progression and enhanced engagement of athletes. This review provides an overview of available tests in different exercise domains identified as relevant (from assessment of single explosive actions to intermittent endurance capacity), forming the basis for recommendations on how to compose a comprehensive yet feasible test battery that may be integrated into the seasonal competition and training plan. The test procedures should cover the performance spectrum of relevance for the individual athlete-also in team sports to account for positional differences. We emphasize the benefits of sport-specific tests, highlight parameters of importance for test standardization, and discuss how the applied test battery may be supplemented with secondary tests directed toward specific energy systems to allow for more in-depth analyses when required (e.g., in terms of an underperforming athlete). The synergy between testing and tracking of match performance (utilizing time-motion or global positioning systems) is highlighted, and although tracking cannot substitute for testing, combining the tools may provide a comprehensive overview of the physiological demands and performance during competition contextualized to the athletes' maximal exercise capacity.

Correlations of Aerobic Capacity with External and Internal Load of Young Football Players during Small-Sided Games

Aerobic capacity plays a crucial role in football performance, making it a focal point in training processes. Small-sided games (SSGs) are widely used in football training, but the relationship between aerobic capacity and running performance during SSGs remains unclear. The aim of this study was to investigate possible correlations between maximum oxygen uptake (VO2max) and running performance in youth football players in SSGs (4:4, 3:3, 2:2, 1:1) with three different pitch sizes per player (150, 100, 75 m2/player). Sixteen male U15 football players participated in the study. Players underwent the Yo-Yo intermittent recovery test level 1, and their VO2max was estimated based on their performance. Subsequently, players participated in SSGs wearing GPS devices to measure internal and external load. Pearson or Spearman correlation was applied for statistical analysis depending on the normal distribution of the data. The results reveal that, for 4:4 and 3:3 relationships, larger pitches led to a greater impact of aerobic capacity (total distance (TD): 4:4, 150 m2/pl, r = 0.715, p = 0.002; 100 m2/pl, r = 0.656, p = 0.006; 75 m2/pl, r = 0.586, p = 0.017). In the 2:2 relationship, the opposite was observed, with more correlations appearing on smaller pitches (TD: 2:2, 100 m2/pl, r = 0.581, p = 0.018; 75 m2/pl, r = 0.747, p < 0.001). In the 1:1 relationship, correlations with VO2max, total distance, and speed were observed only on the larger pitch. In conclusion, the aerobic capacity of young football players can influence running performance indicators in SSGs. Therefore, aerobic capacity could serve as a criterion for team composition, making SSGs more competitive. Additionally, the variation in correlations in the 2:2 relationship and their limited presence in the 1:1 relationship may be attributed to technical-tactical factors, such as increased ball contacts and one-on-one situations typically occurring in smaller setups.

Performance Adaptations to Intensified Training in Top-Level Football

Because physical demands are surging in football (soccer, USA), clubs are more and more seeking players who have a high capacity to perform repeated intense exercise. High-intensity interval training (HIIT), comprising exercise performed at intensities near or exceeding the capacity of aerobic energy systems, effectively enhances the physical conditioning of players. But given that HIIT imposes high loads, it increases the risk of overload-associated match performance decline and injury. This makes some coaches inclined to conduct HIIT in the weeks leading up to the season and during the season. Therefore, the challenge is how to optimize and dose HIIT during these phases, as they can be decisive. Studies have highlighted the utility of conducting periods of intensified training to overcome the risk of overload while at the same time enhancing performance. During intensified training periods of typically a few weeks, intensity is increased by enlarging the amount of HIIT, for example, aerobic high-intensity training or speed endurance training, while volume at low-to-moderate intensity is significantly reduced. The outcome depends on training composition and prescription-most notably, intensity and duration of bouts and recovery. When work intervals are prescribed for a few minutes at intensities > 90% heart rate max (i.e., aerobic high-intensity training), then beneficial adaptations pertaining to aerobic power and capacity are apparent. But when work intervals are conducted at much higher intensities, as all-out efforts or sprinting of typically 10- to 40-s duration with longer recovery periods (i.e., speed endurance training), beneficial adaptations pertaining to anaerobic energy systems, ion handling, and fatigue resilience are commonly observed. In this review, we discuss the utility of conducting intensified training periods to enhance performance in elite football players during the late preparation phase and competitive season.

Game Demands of a Professional Ice Hockey Team with Special Emphasis on Fatigue Development and Playing Position

The aim of this study was to describe the game activity profile of a professional ice hockey team with special emphasis on fatigue development and playing position. Data were collected using a wearable 200-Hz accelerometric system and heart rate (HR) throughout eight official games in a professional ice hockey team (6 defensemen and 11 forwards; n = 122 files). On-ice 10- and 30-m sprint performance, repeated sprint ability and HR responses to the submaximal Yo-Yo Intermittent recovery level 1 test were assessed to determine associations with game performance. Although the 3rd period was largely longer than the 1st and 2nd periods (r = 0.56–0.59), no differences were observed between periods in activity pattern, except a moderate decline in the number of decelerations <-2 m·s-2 per min (Dec2/min) in the 2nd period for forwards (r = 0.06–0.60). Mean HR, time spent >85% HRmax (t85HR), as well as the total number of intense accelerations and decelerations were higher for defensemen. However, demands were similar when expressed relative to time on-ice, except that defenders performed more Dec2/min than forwards in all periods, whereas forwards spent more t85HR during the 2nd period (r = 0.46–0.57). Time spent on ice was inversely correlated with the total number of accelerations (Acctot), accelerations >2 m·s-2 per min (Acc2/min), total decelerations per min (Dectot/min), Dec2/min and t85HR (r = -0.63 to -0.18) and positively correlated with mean HR and peak HR (r = 0.20– 0.53). No significant correlations were found between physical fitness and game activity variables scaled by individual time on ice. Absolute acceleration and HR demands of professional ice hockey seem to differ between playing positions, but not in relation to time on ice. Further, no clear signs of fatigue were captured, possibly due to the longer duration of rest intervals in the 3rd period.

Peripheral muscle function during repeated changes of direction in professional soccer players

PURPOSES

To evaluate peripheral muscle function of the knee extensors during repeated changes of direction in professional soccer players by examining differences between competitive levels, periods of the season and playing positions, and to investigate the relationships between peripheral muscle function and physical activities during matches.

METHODS

Knee extensor peripheral muscle function (twitch peak torque, PT) of 593 male soccer players from 13 European professional clubs competing at 3 different levels was evaluated 4 times during the season. The main outcomes were PT_max (maximal PT, muscle contractility), MP_max (maximal metabolic power exercise intensity) and PT_dec (PT decline, muscle fatigability) obtained during intermittent runs of increasing intensity with multiple changes of direction interspersed with electrically evoked contractions. Relative total and sprint distances covered during a whole match and during short intervals were quantified from a sub-sample.

RESULTS

PT_max and MP_max were higher for first than for second division (p < 0.047; d = 0.15-0.23) and Under-19 players (p < 0.007; d = 0.17-0.25). MP_max was lower (p < 0.016; d = 0.23-0.32) and PT_dec was higher (p < 0.004; d = 0.26-0.39) in the pre-season compared to all the other time points. MP_max was higher for fullbacks than attackers and defenders (p < 0.041; d = 0.20-0.22). PT_dec was higher for defenders than fullbacks, midfielders and wings (p < 0.029; d = 0.21-0.28). PT_max was associated with whole-match relative total distance (p = 0.004; d = 0.26). PT_dec was associated with whole-match relative total distance and relative short-interval sprint distance (p < 0.050; d = 0.18-0.22).

CONCLUSION

The ability to sustain repeated change of direction efforts at high intensities while preserving peripheral muscle function should be considered an important determinant of soccer physical performance.

Effects of High-Intensity Resistance Training on Physical Fitness, Hormonal and Antioxidant Factors: A Randomized Controlled Study Conducted on Young Adult Male Soccer Players

Purpose: The aim of this study was to test the effects of high-intensity resistance training (HIRT) intervention on the physical fitness, hormonal and antioxidant factors of adult male soccer players. Methods: A randomized controlled study design was implemented. Eighteen soccer players (age: 20.3 ± 0.66 years; stature: 174.0 ± 6.01 cm; body mass: 69.1 ± 6.4 kg; body mass index: 22.8 ± 1.6 kg/m2) voluntarily participated in this study. Players were assessed before and after an intervention lasting 8 weeks, with three training sessions a week. Assessments of physical fitness included the Yo-Yo intermittent recovery test level 1 (YYIRT1), 10-, 20-, and 30 m sprint time (ST), running-based anaerobic sprint test (RAST) and change-of-direction time (COD). Hormonal tests included cortisol, testosterone and growth hormone (GH), whereas the antioxidant assessment included superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione (GSH). Results: Between-group analysis revealed no significant differences at baseline, whereas it revealed that HIRT presented significant better results than the control group on YYIRT (p = 0.032), 10 m ST (p = 0.041), 20 m ST (p = 0.040), 30 m ST (p = 0.044), RAST (p = 0.013), and COD (p = 0.031) after the intervention period. The within group analysis revealed that the HIRT group significantly improved the YYIRT1 (p < 0.001), VO2max (p < 0.001), 10 m ST (p < 0.001), 20 m ST (p = 0.006), 30 m ST (p < 0.001), RAST (p < 0.001) and COD (p < 0.001). Moreover, HIRT group significantly reduced the cortisol (p < 0.001) and MDA (p = 0.021), whereas it significantly increased the GH (p < 0.001), testosterone (p < 0.001), SOD (p = 0.009) and GSH (p = 0.005). Conclusions: The HIRT is effective for improving physical fitness, revealing significant better adaptations than controls. Moreover, hormonal and antioxidant adaptations are also confirmed after HIRT intervention.

Impact of COVID-19 lockdown on professional soccer players' match physical activities

AIM

The COVID-19 pandemic forced the 2019-20 Italian Serie A competition to stop and players went into lockdown. During lockdown, players only trained at home, likely having a detrimental effect on players' physical fitness and capacity. This study investigated the effect of the COVID-19 lockdown on professional soccer players' match physical activities.

METHODS

Match activities of 265 male professional soccer players were assessed in two periods prior to (PRE1 and PRE2) and one period following the lockdown (POST) using a video tracking system. Linear mixed models were used to examine differences between-periods in total (TD), very high-speed (VHS), sprint (SPR), high-acceleration (ACC) and high-deceleration (DEC) distances, considering full match data and data from six 15-min intervals.

RESULTS

TD and VHS during POST were lower than the two other competitive periods (p < 0.001, d small-moderate). SPR did not show differences between periods (p > 0.636). ACC and DEC during POST were lower than PRE2 (p < 0.015, d small). Declines in most 15-min intervals after lockdown were observed in TD and VHS.

CONCLUSIONS

There were small differences in the temporal distribution of SPR, ACC and DEC at POST. After the COVID-19 lockdown, soccer players' higher-intensity running activities were similar to those of games played before the lockdown, but TD and VHS decreased, both considering the entire match and 15-min intervals. The temporal distribution of running activities was mostly stable throughout the season.

Relationships between Fitness Status and Match Running Performance in Adult Women Soccer Players: A Cohort Study

Background and Objectives: The aim of this study was twofold: (i) to analyze the relationships between fitness status (repeated-sprint ability (RSA), aerobic performance, vertical height jump, and hip adductor and abductor strength) and match running performance in adult women soccer players and (ii) to explain variations in standardized total distance, HSR, and sprinting distances based on players' fitness status. Materials and Methods: The study followed a cohort design. Twenty-two Portuguese women soccer players competing at the first-league level were monitored for 22 weeks. These players were tested three times during the cohort period. The measured parameters included isometric strength (hip adductor and abductor), vertical jump (squat and countermovement jump), linear sprint (10 and 30 m), change-of-direction (COD), repeated sprints (6 × 35 m), and intermittent endurance (Yo-Yo intermittent recovery test level 1). Data were also collected for several match running performance indicators (total distance covered and distance at different speed zones, accelerations/decelerations, maximum sprinting speed, and number of sprints) in 10 matches during the cohort. Results: Maximal linear sprint bouts presented large to very large correlations with explosive match-play actions (accelerations, decelerations, and sprint occurrences; r = -0.80 to -0.61). In addition, jump modalities and COD ability significantly predicted, respectively, in-game high-intensity accelerations (r = 0.69 to 0.75; R2 = 25%) and decelerations (r = -0.78 to -0.50; R2 = 23-24%). Furthermore, COD had significant explanatory power related to match running performance variance regardless of whether the testing and match performance outcomes were computed a few or several days apart. Conclusion: The present investigation can help conditioning professionals working with senior women soccer players to prescribe effective fitness tests to improve their forecasts of locomotor performance.

Effects of Small-Sided Games vs. Running-Based High-Intensity Interval Training on Physical Performance in Soccer Players: A Meta-Analytical Comparison

Objectives: This systematic review with meta-analysis (SRMA) was conducted to compare the effects of SSG-based interventions vs. running-based HIIT interventions on soccer players' sprinting time (ST), vertical height jump (VJH), and change of direction time (CODt). Data Sources: The data sources utilized were Web of Science, Scopus, SPORTDiscus, and PubMed. Results: An electronic search yielded 650 articles, six of which were included in the present study. Between-group analysis found a significant favoring effect of HIIT-based over SSG-based training interventions for the improvement of linear sprinting time (ES = 0.42; p = 0.012). A within-group analysis revealed a significant favoring effect of HIIT-based training interventions for improving linear sprinting time (ES = 0.42; p = 0.008) and CODt (ES = 1.04; p = 0.005) despite a non-significant effect on VJH (ES = 0.47; p = 0.22). Conclusions: The meta-analytical comparison revealed favoring the effect of running-based HIIT over SSG-based interventions in sprinting performance, although no significant differences were observed for jumping and CODt performance. The findings suggest that SSG-based programs should be supplemented by other training methods that benefit determinant capacities in soccer players.

Detrimental Effects of the Off-Season in Soccer Players: A Systematic Review and Meta-analysis

BACKGROUND

The off-season period in soccer leads necessarily to changes in fitness status. However, there is a lack of systematization that allows identifying the magnitude of these changes in groups participating in off-season training programs compared with those subjected to training cessation.

OBJECTIVE

This systematic review with meta-analysis was conducted to assess the effects of training cessation in off-season training programs on men soccer players' body fat, maximal oxygen uptake (VO_2max), yo-yo intermittent recovery test (YYIRT), vertical jump, sprinting time, and repeated-sprint ability.

METHODS

To qualify for inclusion in the systematic review, studies must have included: (1) a detraining period of ≥ 2 weeks; (2) controlled trials or cohorts of healthy men soccer players with no restriction on age; and (3) a pre-post training cessation or off-season training programs measure of body fat (%), VO_2max (mL kg^-1 min^-1), YYIRT performance (meters), vertical jump (height), sprinting (time), and repeated-sprint ability (total time).

RESULTS

The electronic search yielded 563 articles, and 12 were subsequently included. Significant (all p < 0.05) detrimental training cessation effects were noted for body fat (ES = 0.26), VO_2max (ES = - 1.48), YYIRT (ES = - 0.46), vertical jump (ES = - 0.81), and repeated-sprint ability (ES = 0.68). Similarly, significant (all p < 0.05) detrimental off-season training programs effects were noted for body fat (ES = 0.26), VO_2max (ES = - 0.48), vertical jump (ES = - 0.51), and sprinting time (ES = 0.86). When training cessation and off-season training programs effects were compared, greater detrimental effects were noted after training cessation for VO_2max (p = 0.002) and repeated-sprint ability (p < 0.001).

CONCLUSIONS

Detrimental effects on body composition and physical fitness were observed after both training cessation and off-season training programs. However, off-season training programs seem to ameliorate such detrimental effects on VO_2max and repeated-sprint ability to some extent. The results presented here call for the implementation of more effective off-season training programs among male soccer players.

COVID-19-Related Restrictions and Quarantine COVID-19: Effects on Cardiovascular and Yo-Yo Test Performance in Professional Soccer Players

The present study aimed to verify the quarantine's effects during a serious viral outbreak on the cardiovascular and performance associated with the Yo-Yo test in a sample of professional soccer players. 20 high-level soccer players (n = 20; age: 26 ± 4 years-old; weight: 76.85 ± 6.7 kg; height: 179 ± 6 cm) participated in this study. The intermittent Yo-Yo test was performed pre- and post- COVID-19 quarantine in a random order. During each test, the soccer players' running performance outcomes were monitored using a portable 5-Hz GPS with a 100 Hz accelerometer and a paired t-test was conducted at a p-value of ≤ 0.05. The main results demonstrated significant differences between pre- versus post-COVID-19 quarantine in the following variables: relative distance (161.7 ± 5.9 > 141.1 ± 33.8 m/min), maximal speed (18.7 ± 0.9 > 18.2 ± 0.6 km/h), acceleration (60 ± 20 frequency > 52 ± 16 frequency), deceleration (34 ± 13 frequency > 27 ± 6 frequency), sprints > 19 km/h [0.8 (0.2;3)% >0.5 (0;0.5)%], and in high intensity running distance [16.48 (2.68;41.64)m > 0.827 (0.164;3.0)m]. We concluded that COVID-19-related restrictions and quarantine COVID-19 demonstrated adverse effects on professional soccer players' Yo-Yo tests performance.

Relationships between Training Loads and Selected Blood Parameters in Professional Soccer Players during a 12-Day Sports Camp

The main purpose of this study is to assess the relations between training loads and selected blood parameters in professional soccer players during a preseason sports camp. Fifteen professional soccer players (age: 24.3 ± 5.25 year; height: 182.6 ± 6.75 cm; weight: 76.4 ± 6.72 kg) participated in the 12-day training camp. All the training sessions and friendly games were accurately analyzed with a GPS system. Blood samples were taken from the players and analyzed before the camp (PRE), in the middle (MID), and one day after the camp (POST). Mean total distance covered by the players during the camp was 85,205 ± 2685 m, high-intensity running 12,454 ± 1873 m, and sprinting 639 ± 219 m. The highest aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and C-reactive protein (CRP) values were observed after six days of the camp. The application of intensive training during a 12-day sports camp can be associated with chronic muscle pain with high activity of some blood enzymes (CK, AST) and a high concentration of myoglobin (Mb). During training camps longer than 10 days, it would be necessary to apply, every second or third day, one day of rest, and the training load should not exceed two units every day.

The validity of small-sided games in predicting 11-vs-11 soccer game performance

Predicting performance in soccer games has been a major focus within talent identification and development. Past research has mainly used performance levels, such as elite vs. non-elite players, as the performance to predict (i.e. the criterion). Moreover, these studies have mainly focused on isolated performance attributes as predictors of soccer performance levels. However, there has been an increasing interest in finer grained criterion measures of soccer performance, as well as representative assessments at the level of performance predictors. In this study, we first determined the degree to which 7-vs-7 small-sided games can be considered as representative of 11-vs-11 games. Second, we assessed the validity of individual players’ small-sided game performance in predicting their 11-vs-11 game performance on a continuous scale. Moreover, we explored the predictive validity for 11-vs-11 game performance of several physiological and motor tests in isolation. Sixty-three elite youth players of a professional soccer academy participated in 11 to 17 small-sided games and six 11-vs-11 soccer games. In-game performance indicators were assessed through notational analysis and combined into an overall offensive and defensive performance measure, based on their relationship with game success. Physiological and motor abilities were assessed using a sprint, endurance, and agility test. Results showed that the small-sided games were faster paced, but representative of 11-vs-11 games, with the exception of aerial duels. Furthermore, individual small-sided game performance yielded moderate predictive validities with 11-vs-11 game performance. In contrast, the physiological and motor tests yielded small to trivial relations with game performance. Altogether, this study provides novel insights into the application of representative soccer assessments and the use of continuous criterion measures of soccer performance.

Relationships between Players’ Physical Performance and Small-Sided Game External Responses in a Youth Soccer Training Context

The aim of this study was twofold: 1) To compare players’ physical performance and small-sided game (SSG) external responses among three young soccer age categories (i.e., under 14 (U14), under 16 (U16), and under 18 (U18)); and 2) to examine their relationships among physical performance and SSG external responses in each age category. Players’ physical performance was evaluated via several tests and external responses were collected during a four vs. four plus goalkeepers SSG. Main results showed that while older players presented better linear straight sprinting tests (LSSTs) (U18 and U16 vs. U14, p < 0.01), repeated sprint ability (RSA) (U18 vs. U16 and U14 p < 0.01), and change of direction ability (CODA) (U18 and U16 vs. U14, p < 0.01, ES = 2.34−2.72) performances, these differences were not consistent with their SSG external responses (U16 vs. U14, p < 0.01; U18 vs. U16, p < 0.01). Conversely, higher number of associations between players’ physical performance and SSG external responses were found in younger players in comparison to the older ones. These results suggest that while greater physical performance in younger players (i.e., U14) could allow them to exhibit higher external responses, greater physical performance did not influence older players’ (i.e., U18) SSG external responses.

Short-Term Repeated-Sprint Training (Straight Sprint Vs. Changes of Direction) in Soccer Players

Repeated-sprint training (RST) is considered a critical training method in team sports. It is well known that RST effects may depend on several variables such as the duration of the protocol and repeated-sprint methodology. Few studies have evaluated very short-term protocols and compared different RST modalities. The aim of this study was to compare the effectiveness of 2 week RST including straight sprints or changes of direction (CODs) on physical performance in a sample of soccer players. This study used a randomised pre-post parallel group trial design. The participants were assigned to either an RST group using straight sprints (RST-SS = 18 players) or an RST group using CODs (RST-COD = 18 players). The protocols were: 3 sets of 7 x 30 m sprints for the RST-SS and 7 x 20 + 20 m (one COD of 180°) for the RST-COD, with 20 s and 4 min recovery between sprints and sets, respectively. The following evaluations were performed: 10 and 20 m sprint, agility test, repeated sprint test (RSTbest and RSTmean), and Yo-Yo Recovery Level 1. After the training period, the RST-SS did not report any performance variation, while the RST-COD showed improvements in the 10 m sprint and RSTbest (effect size = 0.70 and 0.65, respectively). The between-group analysis did not report any statistical difference between the RST-SS and the RST-COD. In conclusion, this study did not support the utilisation of a very short-term RST protocol with soccer players, however, the RST-COD presented some additional benefits in sprint performance compared to the RST-SS.

Correlations between body composition, aerobic capacity, speed and distance covered among professional soccer players during official matches

BACKGROUND

The importance of sprinting and high-speed running activities during a soccer match is indisputable. The main purpose of this study was to investigate the relations between the players' speed, aerobic capacity, body composition and distance covered in different speed zones during official soccer matches and to compare the match performance variables according to playing position.

METHODS

Twenty-three professional soccer players (age: 27.9±4.58 y, body mass: 78.8±7.35 kg, height: 181.7±6.53 cm) participated in this study. During 13 weeks of the competitive season, players participated in 16 official matches and completed body composition analyses, sprint tests, multistage shuttle run tests (MST), and incremental running tests (IRTs).

RESULTS

Significant negative correlations were found between sprint distance and percent of fat mass (FM; r=-0.57, P<0.0001), MST (r=0.45, P<0.001), maximal speed (r=0.44, P<0.001). High-speed running (HSR) distance covered by the players during the matches was significantly correlated with FM (r=-0.38, P<0.001) and MST distance (r=0.30, P<0.01).

CONCLUSIONS

These data indicate that professional soccer players with lower fat content and higher levels of aerobic capacity are able to cover longer distances in sprinting and HSR during official matches.

External Load Variables Affect Recovery Markers up to 72 h After Semiprofessional Football Matches

Background: Player tracking devices are commonly used to monitor external load from training and matches in team sports. Yet, how the derived external load variables relate to fatigue and recovery post-training or post-match is scarcely researched. The objective was, therefore, to investigate how external load variables affect recovery markers up to 72 h post-match.

Methods: Semiprofessional players from six teams wore tracking devices during three experimental football matches. External load variables including individual playing duration, total distance, PlayerLoad™, high-intensity running, and high-intensity events were derived from the tracking devices, and blood samples and performance tests from 24–59 players were undertaken post-match. The effect of the external load variables on creatine kinase, myoglobin, and countermovement jump at 1, 24, 48, and 72 h, and 30-m sprint and Yo-Yo intermittent recovery tests level 1 at 72 h post-match, were modeled. Effects were gauged as two standard deviations of the external load and interpreted as the difference between a typical high-load and a typical low-load match. The effects were evaluated with 90% confidence intervals and magnitude-based inferences.

Results: High-intensity running had very likely substantial effects on creatine kinase and myoglobin (moderate factor increases of 1.5–2.0 and 1.3–1.6 respectively), while duration, total distance, and HIE showed small, likely substantial effects. PlayerLoad™ and total distance had likely substantial effects on 30-m sprint time (small increases of 2.1–2.6%). Effects on countermovement jump performance were generally non-substantial. Despite these relationships, the uncertainty was too large to predict the recovery of individual players from the external load variables.

Conclusions: This study provides evidence that external load variables have an effect on recovery markers up to 72 h post-match. Hence, tracking external load in matches may be helpful for practitioners when managing training load and recovery strategies post-match. However, it is recommended that several different external load variables are monitored. Future research should continue to address the problem of predicting recovery from external load variables.