The aim of this study was to apply a training plan to four different-length microcycles (MIC) in soccer and analyze (a) the load within the training weeks and (b) the short-term effect on the matches that were played at the end of each microcycle. An intervention training program applied to microcycles of five, six, seven and nine days during two seasons of the Cypriot Fist Division. The GPS technology and subjective (wellness, RPE) assessments were used to monitor the load throughout trainings and games. In weekly external load, there were differences between the four microcycles, with a lower load in MIC5 for all the parameters and higher on MIC9 in the most of them (p < 0.05). In RPE, MIC9 (229 ± 60 arbitrary units (au)) differed significantly from MIC5 (229 ± 60 au, p < 0.001), MIC6 (281 ± 67 au; p < 0.001) and MIC7 (297 ± 48 au, p = 0.009). MIC5 also differed from MIC6 (p = 0.001) and MIC7 (p < 0.001). In the game external load, the only differences found in GDEC2 (game decelerations) were between MIC7 (68 ± 10 number (n)), MIC5 (61 ± 11 n, p = 0.035) and MIC6 (60 ± 10 n, p = 0.002); in GSPEF (game speed efforts), between MIC5 (40 ± 17 n), MIC7 (48 ± 14 n, p = 0.004) and MIC9 (48 ± 16 n, p < 0.001) and between MIC6 (41 ± 14 n), MIC7 (p = 0.009), and MIC9 (p = 0.009); in GMPW5 (game metabolic power efforts), between MIC7 (1307 ± 271 n), MIC5 (1201 ± 340 n, p = 0.035) and MIC6 (1178 ± 261 n, p = 0.001). No differences were found for wellness and perceived exertion. It is important for performance coaches to adapt the training load to the length of the microcycle, applying a lower load to short training weeks and manage the load fluctuation on long training weeks in terms of volume, intensity and recovery. In our study, the results confirmed that this strategy could result in similar performance in the games, regardless of microcycle length.

Perceived exertion (RPE, RPE_dur) and wellness scores (Hooper) are common methods to assess the training load and readiness in football. However, in professional football, there is a lack of data concerning the application of these tools in microcycles of different durations. Therefore, the purpose of this study was to explore the correlations between (a) RPE, RPE_dur, and weekly external load (EXLD) and (b) Hooper and EXLD within microcycles of different durations. Independent of the microcycle’s length, RPE and RPE_dur correlated with the EXLD. In MIC5, RPE and RPE_dur correlated with the EXLD, except for accelerations > 3 m/s² (ACh) and distance > 25.5 km/h (SPvh). In MIC6, RPE and RPE_dur correlated with the EXLD, except Ach (with RPE). In MIC7 and MIC9, RPE and RPE_dur correlated with the EXLD, except RPE with ACh. For Hooper variables, independent of the microcycle duration, SRN and FTG had more correlations in comparison to SLP; the same finding was observed in MIC7 and MIC9, but SRN and SLP in MIC5 and MIC6, respectively, had no correlations. Multiple regression analysis showed that for RPE, the main predictors are total distance (TD), metabolic power distance > 50 w/kg (PWvh), and ACh, which can explain 31% of the variance, but for RPE_dur, 58% can be explained by DUR, TD, and PWvh. For SLP, the predictors FTG and SRN can explain a very small percentile of the variance (1%, 4%, and 6%, respectively). The main findings were the multiple correlations between RPE, RPE_dur, Hooper, and microcycles of different durations; most of them were found for long durations. This tendency is similar to that described in the literature for microcycles of the same duration. (a) EXLD has a stronger correlation with RPE_dur than with RPE, and (b) FTG and SRN are the best predictors of the EXLD during the upcoming training session. It is recommended that fitness coaches use these tools to assess and forecast the training load; thus, they will be able to prepare more effective sessions during microcycles of different durations.

The aim of this study was twofold: (a) to examine the differences on physical indexes between players of different playing positions and (b) to reveal the correlations between their physical parameters and the running profile within the weekly microcycles. The subjects (n = 44) were separated into five positions: central defenders (n = 7), wide defenders (n = 9), midfielders (n = 13), wingers (n = 8) and strikers (n = 7), and all of them belonged to a professional 1st division European team during the 2020–21 and 2021–22 seasons. An incremental treadmill protocol was used to assess the VO₂max, vVO₂max and the vRER in the last week before the regular season. Then, during the first semesters, external load data were collected for two consecutive seasons to analyze the running profiles of the different positions. There were no differences on physical parameters between the players of various positions, but interestingly there were different correlations with the external load during the microcycles. Central defenders did not show any correlation. For the other positions, correlations were found between respiratory exchange ratio (vRER) and metabolic power efforts (MPWEF) (p = 0.028, r = 0.721) for wide defenders, between vRER and medium intensity accelerations (ACC2) (p = 0.004, r = 0.741) for midfielders, medium intensity decelerations (DEC2) (p = 0.01, r = 0.685), metabolic power zone 5 (MPW5) (p = 0.016, r = 0.652), MPWEF (p = 0.005, r = 0.725), and also between maximal rate of oxygen consumption (VO₂max) and high intensity decelerations (DEC3) (p = 0.045, r = 0.564), metabolic power zone 4 (MPW4) (p = 0.026, r = 0.614), MPW5 (p = 0.017, r = 0.646), MPWEF (p = 0.01, r = 0.685). A correlation between velocity on VO₂max (vVO₂max) and ACC2 (p = 0.038, r = 0.733), MPW5 (p = 0.005, r = 0.873), and MPWEF (p = 0.009, r = 0.84) was found for the wingers. Finally, there was a correlation between vRER and MPWEF (p = 0.026, r = 0.866), and between vVO₂max and high intensity accelerations (ACC3) (p = 0.03, r = 0.801) for the strikers. Our study supports that the external load of players in different positions during the training sessions is correlated with their physical indexes. These correlations are determined mostly by their tactical role, but not from their physical level, as there were no differences.