A comprehensive analysis of internal and external load monitoring systems in basketball.

Different methods have been developed to monitor training load in basketball, so it is necessary to establish a common criterion to identify the reference variables to control the player's load. This study aimed to determine the most appropriate variables to measure each type of load. An retrospective methodology was used to monitor 16 professional players of the Spanish basketball first division (ACB league) during 19 training sessions. Five measurement systems were used for monitoring: the load programmed by the coach, heart rate, WIMU Pro inertial devices, the SIATE tool, and the RPE-CR10 subjective load scale. A Coefficient of Variance statistical analysis (CV%) was performed to measure the stability of the intrasession variables, a Principal Component Analysis to analyse the similarity between variables, a Cross-Correlation analysis to see the relationship and proportionality between variables, a Linear Mixed Model to analyse the innate individual influence of the subjects to each variable, a STEN normalisation to compare the behaviour of the variables between sessions and a Bland Almand Plot analysis to compare the agreement of the measurement variables. The results suggest that SIATE variables, when weighted by time and participation, along with the coach's planned load, serve as a key and robust indicators of both internal and external load. When resources allow, it is recommended to complement these with objective external load measures (e.g., Player Load, Distance) and subjective internal load indicators (e.g., sRPE).