## 1 Introduction  
Training load in football can be evaluated easily and reliably by using the perceived exertion (RPE) method. The RPE score is collected within the first 30 min after the end of the training session, where the players should estimate how hard the training was on a scale between \"1\" and \"10\" [1]. However, to better represent the training load (volume and intensity), another method was developed: \"RPE \(\times\) training duration\" (RPE\({}_{\text{dur}}\)) [2]. This method is correlated with heart rate training zones [1] and is a very reliable indicator of internal load in football [3]. The use of the \"Hooper Questionnaire\" [4] to monitor the wellness state can provide important information on players' readiness to train or play. It can consist of various questions, but to be more reliable, it should not include too many [5]. The most commonly used parameters are (a) fatigue (FTG), (b) muscle soreness (SRN), (c) sleep quality (SLP), and (d) stress [4; 6]. All these parameters are correlated with biochemical responses [6] and external load (EXLD) during training sessions; thus, they could possibly forecast the upcoming training load [7]. It is important to know that FTG, SRN, and SLP are not highly correlated with RPE\({}_{\text{dur}}\)[8]. To attain the desired results, the weekly training load must be adjusted. Therefore, to achieve high performance in official games, it is necessary to apply adequate load during the week in high-speed running distance (HSR) and RPE\({}_{\text{dur}}\), but not at an exaggerated level, as this could lead to negative results [9; 10; 11]. In this context, other studies have suggested that football players should be trained at high intensity to be able to cope with the worst-case scenarios that they will face during games; thus, fitness coaches should prepare the training sessions accordingly [12; 13; 14; 15], always keeping in mind that accumulated fatigue could affect the game result [11]. The duration of the microcycle varies because it is adjusted to the game calendar that is established by football federations [15; 16]. This variety in duration influences the training load [14; 15; 17; 18; 19]. But there are similarities between a \"normal week\" (7 days) and microcycles of different durations in an intra-week periodization model. The highest load is always applied in the middle of the week and a lower load is applied closer to the games (MD+1, MD+2, MD\(-\)2, MD\(-\)1) [20; 21; 22]. To avoid the negative outcomes of accumulated load during short-duration microcycles, the primary objective is to recover from the previous game and focus only on improving tactical football skills, not on physical attributes [23]. Although this approach is the most common, many coaches and trainers put their own spin on it by applying different methodologies within this framework [24]. Future data should justify the training context that could be applied on each specific day to achieve better load fluctuation [25] but should also help elucidate which model of microcycle is the most suitable, because there are different protocols in the literature [11]. In contrast, in larger microcycles, there is sufficient time to recuperate from both the last game and the intra-week training load [26]. Out of microcycles consisting of three, four, and five training sessions, the latter has the highest load in terms of several parameters: distance (TD); medium-speed distance, at 14.4-19.8 km/h (SPm); high-speed distance, at \(>\) 19.8 km/h (HSR); accelerations (ACCs); and decelerations (DECs) [18]. In another study [15], the length of the microcycle had no effect on TD, high-intensity accelerations \(>\) 3 m/s\({}^{2}\) (AChs), the number of speed actions (SPAs), and distance \(>\) 25.2 km/h (SPvh), but it did have an impact on high-intensity decelerations \(<\) -3 m/s\({}^{2}\) (DCs) and high-metabolic-load distance \(>\) 25.5 w/kg (HMLD).