INTRODUCTION
In soccer, physical demands are typically evaluated based on match running performance (MRP). Approximately 85–95% of MRP is related to low-to-moderate-intensity activities (i.e., walking, jogging, and running) and only 5–15% to high-intensity activities (i.e., highspeed running [HSR] and sprinting [SPR]) [1]. The aerobic system is therefore the predominant source of energy during most matches [1, 2, 3, 4], making aerobic fitness crucial for football performance (i.e., aerobic performance [AP]). Specifically, adequate AP helps soccer players to maintain high-intensity actions at an appropriate level, delay the development of match fatigue, and accelerate postmatch recovery [2, 5].
Laboratory-based parameters, such as maximal oxygen uptake (
Due to their field-based applicability [10, 11, 12], maximal aerobic speed (MAS) and the Yo-Yo test score have also become commonly used parameters for evaluating AP [10, 11, 12, 13]. MAS is defined as the lowest running velocity that elicits
AP indicators, including
The evident inconsistency in findings may be attributed to the different samples analysed or methodologies implemented. Firstly, some studies analysed data of soccer players in matches held 15–20 years ago [9, 17, 19, 23, 28, 29]. As longitudinal analyses of soccer matches have indicated that MRP has changed tremendously over the last decade [30], the findings from these studies are probably limited in current application. Secondly, studies rarely considered match-related factors that can significantly affect MRP or AP, such as playing position, match outcome, match location, and opponent quality. To the best of our knowledge, only two studies have shown a position-specific relationship between MRP and AP [7, 8], and no study has yet statistically controlled for playing position and any other factors that can influence this relationship (contextual factors). Thirdly, studies investigating the position-specific relationship between MRP and AP exclusively implemented simplistic statistical approaches [7, 8], which are not able to control the natural variability in MRP [31, 32, 33], as opposed to more advanced statistical techniques such as the linear mixed model (LMM). As a result, the true effect of AP on MRP may have been obscured, possibly leading to potentially misleading findings. Consequently, actual knowledge on the relation between AP and MRP remains limited.
Taking into account that these methodological limitations represent a significant gap in the current literature, this study aimed to: i) evaluate the relationship between AP and MRP when statistically controlling for specific playing position, selected contextual factors and individual variability of soccer players, ii) identify which routinely measured AP indicators show the strongest predictive value for MRP variables.
MATERIALS AND METHODS
Design
Players competing at the highest level (current national champion) in one of the central European leagues over one half-season were observed. MRP was measured using portable global positioning system (GPS) units in all domestic league and European cup matches (including qualification) from July to December 2023. MRP for at least 75 min from the start of matches was analysed [32, 34]. AP indicators (independent variables) were examined using laboratory (ergospirometric exercise test to volitional exhaustion) and field tests (Yo-Yo IRT2) at the beginning of the pre-season period. The relationship between MRP and AP was analysed first, followed by additional consideration of contextual factors such as match location (H/A) or competition level (EC/DL).
Participants
The MRP of 21 professional players (mean ± SD, age: 25.2 ± 3.5 years; height: 184.1 ± 6.1 cm; body mass: 81.0 ± 6.0 kg) playing in the same soccer team was analysed. Only outfield players were observed, and they were divided into the following playing positions: central backs (CBs; n = 6), full backs (FBs; n = 5), central midfielders (CMs; n = 3), wide midfielders (WMs; n = 4), and strikers (STs; n = 3). The categorization of players into specific playing positions was based on the system of play (1-5-4-1) used in the matches analysed, which includes in the defensive formation three central backs and two full backs, in the midfield formation two central midfielders and two wide midfielders, and in the attack formation one striker. Players were observed in a total of 29 matches (19 matches in domestic league and 10 matches in European competition), resulting in 216 match performances (CBs: n = 77; FBs: n = 43; CMs: n = 41; WMs: n = 27; STs: n = 28). All players were fully informed about the study objectives and signed an informed consent form agreeing to participate in the study. The typical team microcycle for this period had a double peak (two matches in a week) (Table 1).
TABLE 1
Overview of the weekly training/match in-season microcycle in relation to a match day
| Day | Field-based training | Gym training | Match |
|---|---|---|---|
| MD +1 | Recoverya, top-up (60 min)b | 30 mina,b | |
| MD -2 | 60 min | ||
| MD -1 | 60 min | ||
| MD | 20 minc | 90 min | |
| MD +1 | Recoverya, top-up (60 min)b | 30 mina,b | |
| MD -1 | 60 min | ||
| MD | 20 minc | 90 min |
Measurements were performed according to the Declaration of Helsinki and the ethical standards in sport and exercise science research described by Harriss et al. [35]. The study followed valid principles, regulations, and international guidelines for research involving human participants and was approved by the institutional ethics committee (Ethical Commitee of Faculty of Physical Education and Sport, Charles University, Prague, no. 068/2024).
Procedures
MRP assessment
GPS units (SONRA, StatSports, Newry, Northern Ireland) were used to measure the performance of players. The scanning device had a gyroscope (100 Hz), an accelerometer scanning in the x-, y-, and z-axes (100 Hz), and a magnetometer (10 Hz). The GPS technology is valid and reliable for monitoring external workloads during competitions [36]. All devices were activated 30 min before data collection to connect and synchronize the GPS signal from satellites. Players wore the same unit over the whole season to avoid inter-unit error [37], although high inter-unit reliability was reported by Beato and de Keijzer [38].
MRP was assessed based on the TD covered during matches and distance covered in three speed categories: HSR (19.8–25.1 km · h−1), SPR (≥ 25.2 km · h−1), and HIR (> 19.8 km · h−1). As MRP was measured in players playing for at least 75 min (cut-off point) from the start of matches, all indicators were presented in relative units, converted per minute.
AP assessment
All AP tests were performed at the beginning of the pre-season period. Laboratory AP measures were assessed during graded exercise tests (GXTs) to volitional exhaustion and included
AnT was determined using the ventilatory threshold method based on ventilation (VE) plots and ventilatory equivalents (VE/
The field-based Yo-Yo IRT2 was conducted after all players were fully familiarized with the test procedure. The test started at 13 km · h−1 and consisted of 2 × 20-m shuttle runs at increasing velocities with 10 s of active recovery between shuttles [40]. The running pace was dictated by an audible signal. Stepwise speed increments followed until participants either failed to reach the line (objectively evaluated by two experienced researchers) twice or felt too exhausted to continue at the required speed (subjectively evaluated). Before the Yo-Yo test, all players conducted a standardized warm-up. They performed the test on an official natural grass field, wearing footwear that met the standards required by the sport. The AP values are presented in Table 2.
Statistical analysis
The differences between AP and MRP among soccer players in different positions were analysed first. Due to unequal variances combined with different numbers of observations among the groups, the non-parametric Kruskal–Wallis H test and Dunn’s post-hoc test were used to compare the variables. Epsilon squared (ε2) was used as a measure of the effect size. The distributions of all observations suggested that their skewness and kurtosis indices do not indicate large normality violations (skewness and kurtosis below 1). The skewness index was 1.45 only for the SPR distance, and the kurtosis index was 2.53 for the SPR distance and −1.33 for the
Linear mixed models were used to assess the relationship between AP and MRP when controlling for individual players, positions, competition levels (EC/DL), and match locations (H/A) and considering the interaction between position and AP. Visual analysis of the distributions of the residuals and the Kolmogorov–Smirnov test (mixed models module; Jamovi software) generally did not indicate significant violations of the normality conditions. MRP was used as the dependent variable and AP as the main independent variable. Position, competition level, and match location were considered additional (control) independent variables. The main and additional independent variables were modelled as fixed effects and the player effect as a random effect (random intercept). Due to the relatively high correlation coefficients between the AP parameters and given the number of observations analysed, models were estimated separately for each parameter. Initially, models without interactions were estimated, and interaction effects between position and individual AP parameters were added. For significant relationships between the main independent variables (AP variables) and the dependent variables (MRP variables), as indicators of effect size standardized coefficients are presented, which can be interpreted as regression coefficients, where values of 0.10–0.29 are defined as small, values of 0.30–0.49 as medium and values of 0.50 or more as large [41]. The aim of the models estimated first was to assess the relationship between AP and MRP under statistical control for the additional (control) variables (competition level, match location, and position). The main aim of the models consequently estimated was to evaluate the interaction effects of the AP parameters with position on MRP. The analysis was performed on the centred variables, with simple coding used for the qualitative variables interacting with the AP parameters. The CB position was used as the reference position because of the deviating requirements on this position from the other positions relative to MRP and AP. This analysis was performed in Jamovi (version 2.3.28).
RESULTS
AP and MRP differences according to playing position
Among the players, the lowest
TABLE 3
Descriptive statistics of MRP and AP and differences between players in soccer-specific playing positions
[i] Superscripted letters indicate significant post-hoc differences (p < 0.05) when compared to specific playing positions.
[ii] ε2, indicator of the effect size; CB, central back; FB, full back; CM, central midfielder; WM, wide midfielder; ST, striker; MRP, match running performance; AP, aerobic performance; TD, total distance; HSR, high-speed running; SPR, sprinting; HIR, high-intensity running;
The CBs covered significantly lower TD, HSR distance, and HIR distance than the other players. A significantly greater TD was recorded in the CMs than in the WMs. The CBs and CMs demonstrated a lower SPR distance than the other players. Additionally, the CMs covered a lower HIR distance than the FBs and WMs (Table 3).
General associations between AP and MRP
Positive correlations were observed between the AnT and Yo-Yo IRT2 score and all MRP indicators. Additionally, relatively strong correlations were noted between the
TABLE 4
Pearson correlation coefficients between aerobic performance and match running performance indicators without disaggregation by soccer-specific playing positions
Relationships between AP and MRP interacting with playing position and contextual factors
In the models estimated first, there was a significant positive association between the
TABLE 5
Relationships between
| TD | HSR | SPR | HIR | |||||
|---|---|---|---|---|---|---|---|---|
| Fixed effects | b | SE | b | SE | b | SE | b | SE |
| Intercept | 109.954*** | 0.533 | 6.821*** | 0.201 | 2.374*** | 0.202 | 9.195*** | 0.380 |
| Pos l (1–2) | -0.888 | 1.822 | 2.832*** | 0.665 | 2.206** | 0.660 | 5.043*** | 1.246 |
| Pos 2 (3–2) | 0.378 | 2.181 | 1.368 | 0.825 | 0.636 | 0.832 | 2.014 | 1.563 |
| Pos 3 (4–2) | 0.619 | 1.653 | 2.808*** | 0.607 | 1.804** | 0.604 | 4.617*** | 1.140 |
| Pos 4 (5–2) | 3.023 | 1.700 | 2.111** | 0.636 | 1.978** | 0.635 | 4.109** | 1.197 |
| 1.920 *** | 0.285 | 0.173 | 0.106 | -0.068 | 0.105 | 0.105 | 0.198 | |
| H/A | 2.544*** | 0.688 | 0.406* | 0.159 | 0.244** | 0.091 | 0.644** | 0.211 |
| EC/DL | 3.225*** | 0.775 | 0.425* | 0.182 | -0.013 | 0.105 | 0.399 | 0.244 |
| Random effects | Variance | Variance | Variance | Variance | ||||
| Player ID | 2.499 | 0.605 | 0.725 | 2.462 | ||||
| Residual | 24.620 | 1.301 | 0.427 | 2.290 | ||||
| R2 marginal | 0.541 | 0.550 | 0.395 | 0.523 | ||||
| R2 conditional | 0.583 | 0.693 | 0.776 | 0.777 | ||||
| AIC | 1330.297 | 715.702 | 498.600 | 852.805 | ||||
| Models with interactions | ||||||||
| TD | HSR | SPR | HIR | |||||
| Fixed effects | b | SE | b | SE | b | SE | b | SE |
| Intercept | 111.357*** | 1.357 | 6.990*** | 0.598 | 2.244** | 0.613 | 9.230*** | 1.160 |
| Pos l (1–2) | -1.505 | 2.504 | 3.266** | 0.999 | 1.929 | 0.987 | 5.179* | 1.886 |
| Pos 2 (3–2) | 2.981 | 6.257 | 2.744 | 2.786 | 0.364 | 2.863 | 3.101 | 5.421 |
| Pos 3 (4–2) | -1.118 | 1.941 | 2.986** | 0.803 | 1.664 | 0.800 | 4.651* | 1.526 |
| Pos 4 (5–2) | 0.808 | 2.168 | 2.155* | 0.939 | 1.437 | 0.952 | 3.590 | 1.809 |
| 1.418* | 0.521 | 0.020 | 0.221 | -0.077 | 0.224 | -0.054 | 0.425 | |
| H/A | 2.531*** | 0.690 | 0.405* | 0.159 | 0.245** | 0.091 | 0.645** | 0.211 |
| EC/DL | 3.192*** | 0.777 | 0.414* | 0.183 | -0.014 | 0.106 | 0.391 | 0.244 |
| Posl* | -1.923 | 1.542 | -0.099 | 0.613 | 0.110 | 0.608 | 0.023 | 1.161 |
| Pos2* | -2.132 | 1.945 | -0.256 | 0.878 | -0.004 | 0.905 | -0.258 | 1.712 |
| Pos3* | -0.815 | 0.673 | 0.208 | 0.289 | -0.007 | 0.292 | 0.202 | 0.555 |
| Pos4* | -1.377 | 1.049 | -0.088 | 0.411 | -0.410 | 0.404 | -0.503 | 0.773 |
| Random effects | Variance | Variance | Variance | Variance | ||||
| Player ID | 2.234 | 0.753 | 0.878 | 3.080 | ||||
| Residual | 24.778 | 1.303 | 0.427 | 2.292 | ||||
| R2 marginal | 0.553 | 0.532 | 0.361 | 0.491 | ||||
| R2 conditional | 0.590 | 0.703 | 0.791 | 0.783 | ||||
| AIC | 1331.821 | 721.414 | 503.960 | 858.760 | ||||
TABLE 6
Relationships between AnT and MRP with statistical controls for player position, match location, competition level and interaction effects of AnT with player position.
TABLE 7
Relationships between MAS and MRP with statistical controls for player position, match location, competition level and interaction effects of MAS with player position.
TABLE 8
Relationships between YoYo IRT2 and MRP with statistical controls for player position, match location, competition level and interaction effects of YoYo IRT2 with player position.
For every 1 m increase in the Yo-Yo IRT2 score, the TD increased on average by 0.019 m/min, HSR distance by 0.004 m/min, and HIR distance by 0.005 m/min. The standardized coefficients for the relationship between Yo-Yo IRT2 score and TD, HSR distance, and HIR distance were β = 0.43, 0.35 and 0.30, respectively. Additionally, the match location was systematically related to MRP when controlling for the other variables. The players had significantly higher MRP indicators in home matches than in away matches (TD: 2.5 m/min, HSR distance: 0.4 m/min, SPR distance: 0.24 m/min, and HIR distance: 0.65 m/min). Significant relationships were also noted between the competition level and TD and HSR distance, with the players having significantly higher MRP values in European competitions (TD: 3.0 m/min, HSR distance: 0.42 m/min). In some cases, MRP differed between the CBs and other players (Tables 5–8). Adding interaction effects generally did not strongly affect the model fit. There were no significant interaction effects of the AP indicators with the player position, indicating a relatively similar relationship between the AP and MRP indicators in all positions studied compared to the control position (CB) (interaction models: Tables 5–8).
DISCUSSION
This was the first study designed to evaluate the relationship between AP and MRP while statistically controlling for playing position and contextual factors, and at the same time accounting for players’ individual variability in MRP. The main finding is that despite the differences in AP and MRP among the players studied, AP is related to MRP independently of playing position and contextual factors. A higher AP was positively associated with the TD covered during matches, and a higher Yo-Yo IRT2 score also positively associated with the HSR and HIR distances. These findings demonstrated that, regardless of position, enhancing AP may help players sustain greater match workloads, making it one of the key targets for conditioning programmes.
Differences in AP and MRP according to soccer-specific playing positions were analysed. The lowest AP, including the
Our study showed positive correlations between the AP and MRP indicators. As in the study by Bangsbo and Lindquist [23], we observed a correlation between the
Similar to the report by Helgerud et al. [9], we observed a correlation between the AnT and MRP indicators. Modric et al. [8] reported that AnT correlated with HSR, SPR, and HIR distances but only among side players (FBs and wingers). Cairns [49] found that low AnT levels were associated with raised lactate and hydrogen ion (H+) concentrations, a decrease in intramuscular pH, and metabolic acidosis. Low AnT levels may therefore limit the MRP indicators related to the amount of energy consumed in low- (mitochondrial metabolic pathways) and high- (anaerobic metabolic pathways) intensity exercises.
We also observed positive correlations between the MAS and TD, HSR distance, and HIR distance. Correlations between performance in the MAS test (an indirect method of MAS determination) and the TD or HSR distance in elite male soccer players were reported only by Krustrup et al. [17] and Kalapotharakos [21]. The discrepancy in the results may be explained by the different ways in which MAS was determined. In our study, the MAS was measured using a direct laboratory ergospirometric method. Non-laboratory methods can underestimate or overestimate MAS due to differences in protocols (e.g., shuttle vs. straight-line running) and estimation of MAS based on the maximum load in the test and therefore at different
The present in-depth analysis showed that AP was associated with MRP in the same way regardless of playing position and contextual factors. In detail, while controlling for playing position and match-related contextual factors, we found significant positive associations between the
Limitations
Despite the findings of the current study, there are some limitations to be considered. The main limitation of our research is the fact that we included only one soccer team that presented the highest possible level in the national competition, which is also related to the small sample size and, at the same time, the limited sample size of the individual playing positions. This limits the generalizability of our results to teams with a lower sporting level, indicating the need for additional analysis and cautious interpretation. To overcome this limitation, further studies should consider including more soccer teams with different performance levels and various tactical formations. Another limitation is that, as in many previous studies [7, 8, 17, 24], AP was tested only at the beginning of the preseason and not after the end of it or even during the whole season [51]. Finally, other contextual factors, such as match score, opponent level, or opponent team formation, were not considered.
CONCLUSIONS
Despite individual variability of soccer players, AP is related to MRP independently of playing position and contextual factors. Higher values of all measured AP indicators are positively associated with the TD covered during a match. Additionally, a higher Yo-Yo IRT2 score is also positively related to the HSR and HIR distances. The strongest predictors for TD were
Practical Applications
This research allows practitioners to identify physical match outputs using the selected AP indicators. Players characterized by a higher level of AP showed a greater MRP. This may significantly impact training strategies. Knowing the pre-season AP level of soccer players allows a certain degree of prediction of their on-field performance during the season. Additionally, by knowing the AP values of individual players before the season, conditioning coaches, in order to obtain the appropriate AP level for each playing position, can individualize training, taking into account the requirements for soccer players in each position.
Finally, knowing the predictive power of individual AP indicators can influence testing strategies in the pre-season period. A better understanding of the relationship between individual AP indicators and MRP will allow coaches to select exercise tests appropriate for their conditioning philosophy and playing strategy.
In summary, this study emphasized the value of integrating AP metrics into individualized training and player role management in elite soccer. However, the findings should be interpreted with caution due to the limited sample. Future research should involve broader and more diverse team samples, assess AP at multiple time points throughout the season, and account for additional contextual influences to further refine understanding of the relationship between AP and MRP.
