## 1 Introduction
In indoor sports, in recent decades, Local Positioning Systems, LPS, are being applied for monitoring players during training and competition. The technology associated with LPS for data collection (ultra-wideband radio frequency) involves the placement of signal emission-reception systems that, in sports facilities where matches are played, are not allowed by federations and institutions during official matches, as well as the use of inertial devices on the body of athletes. Therefore, there is a lack of reference values derived from LPS in high-level competitive players and in competition. It is necessary to know the thresholds of the objective external load variables that occur during official competition with professional basketball players, as this will allow the development of more precise conditioning programs adjusted to this population. The highest quality IMUs on the market have specific software for processing the raw data obtained during monitored sports practice. By default, these software packages establish a series of reference values to identify actions or ranges of movement. Thus, almost all of them establish that the concept of sprinting is performed when an athlete moves at more than 24 km/h. From this value, speed ranges are established. The five speed ranges defined in the SPro software of the company RealTrack Systems (Almeria, Spain) are as follows: Very Low/Standing, Low/Walking, Moderate/Jogging, High/Running, and Very High/Sprinting. However, it is necessary to have a critical position with respect to these proposed intervals (which come from the analysis of the activity of soccer players), and to analyze if they are really applicable to other sports specialties and other populations. Monitoring of basketball teams has identified that the players have been running at their maximum intensity during training and competition. The speeds reached are conditioned by the dimensions of the playing field (28 \(\times\) 15 m in FIBA basketball), and it is very difficult to reach the reference values presented in the literature. The establishment of the reference thresholds should be carried out taking into account the maximum demands made by the players during competition, the gender of the athletes, and the competitive level, generating specific thresholds for each population of athletes. In order to carry out comparative studies between different sports modalities, it will be important to take into account both the absolute value (maximum) and the relative value (specific ranges). Researchers have begun to customize these thresholds to the populations under study. To do so, they record the actions they want to analyze, and, based on them, with the raw data provided by the IMUs, they make the corresponding clusters according to the values obtained. In school populations, studies are found that propose the following thresholds within physical education classes for teaching basketball [27] or soccer [28]: walking \(\leq\) 6 km/h, jogging 6-12 km/h, running 12-18 km/h, and sprinting \(\geq\) 18 km/h. For their part, [PERSON] et al. [29] again adapted these ranges to their school context and group of students by reducing the values as follows: walking \(\leq\) 5.2 km/h, jogging 5.2-10.5 km/h, running 10.5-15.7 km/h, and sprinting \(\geq\) 15.7 km/h. This adaptation has also been made in studies on the sport of basketball. The literature contains proposals for speed ranges according to the sex of the players, as well as age and competitive level (Table 1). These ranges differ fundamentally according to the methodology used for the classification, the gender, the sport level of the sample, and the IMUs used. Some researchers obtained the data during collective game situations, five vs. five, during training, in simulated game situations, or during competition. These reference values can serve coaches to adjust the design of training tasks to the real demands of competition.