An innovative RPE-based approach using machine learning to analyse starter and substitute training load in soccer
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
Department of Education and Sport Sciences, Pegaso Telematic University, 80143 Naples, Italy
Higher Institute of Sport and Physical Education of Ksar-Said, University of La Manouba, Manouba, Tunisia
Naufar Center, Doha, Qatar
Department of Human Science and Promotion of Quality of Life, San Raffaele Open University, 00166 Rome, Italy
Cardiology Rehabilitation Unit, IRCCS San Raffaele, Rome, Italy
Department of Systems Medicine, University of Rome Tor Vergata, Roma, Italy
Department of Performance and Sport Science, Hellas Verona, Verona, Italy
Pisa Sporting Club, Pisa, Italy
Biol Sport. 2026;43:1473–1485
Current methods to distinguish starters from substitutes are typically based on playing time. Not considering the physical demands and internal load of different positions can lead to ineffective training and recovery protocols. The aim of this study was to examine whether a k-means clustering approach applied to session-RPE can generate role-specific thresholds that meaningfully differentiate match load profiles between starters and substitutes. We analysed 1,450 player-matches from four professional Italian Serie A teams, using video match analysis to measure total distance (TD) and high-intensity activities: metabolic power events (MPE), high-speed running (HSR), and sprint running (SR). Players were divided based on the role as follows: forwards (FWs), midfielders (MFs), full-backs (FBs), and centre-backs (CBs). Individualized sRPE zones (low, medium, high) were identified with the K-means clustering approach discriminating starters from substituted. FWs, MFs, and FBs were considered substituted, and compensatory training was recommended when the sRPE was within the medium sRPE zone or lower (FWs ≤ 695 a.u., MFs ≤ 711 a.u., and FBs ≤ 726 a.u.). Compensatory training particularly focused on SR was recommended at sRPE = low for FWs (≤ 326.1 a.u.), and at a sRPE ≤ medium for MFs (≤ 711 a.u.). CBs were defined as starters when reporting sRPE values ≥ medium sRPE (> 446 a.u.), and SR training was always recommended. The proposed sRPE-based k-means approach distinguishes fatigued from non-fatigued players, guiding decisions about who should prioritise recovery. Role-specific sprint recommendations help coaches provide appropriate high-velocity exposure to prevent hamstring injuries.
Keywords
Session RPE, Compensatory training, K-means clustering, Training load, Football
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