Neuromuscular fatigue in professional football goalkeepers and its relationship to absolute and relative training load

Abstract The aims of the study were to investigate (1) if acute or sustained neuromuscular fatigue (NMF) occurred from goalkeeper (GK) training in football and (2) the relationship between objective training load variables collected across different GK training conditions to NMF or subjective measures of training load. NMF was assessed through a countermovement jump protocol using measures of jump height (JH), peak power (PP) and flight time: contraction (FT:CT) across 3 time points; pre training (PRE), post training (POST) and 24 hours post training (POST24) across 4 different training conditions; 1 v 1, agility, crossing and reactions. The objective training load was measured for each GK session through global positioning system (GPS) / accelerometer variables and subjective measures of session rating of perceived exertion (sRPE). The differences, relationships and interaction across the 3 time points and the 4 training conditions were analysed and the results found that the GK’s mean JH and PP increased PRE to POST (38.9 to 40.1cm P < 0.001 and 50.5 to 51.5w/kg P < 0.05 respectively) across the 4 conditions. Although evidence was found that a small reduction in JH and PP occurred for the agility condition it was not deemed significant enough to conclusively identify acute NMF. Objective training load variables showed inconsistent relationships across the GK training conditions and no direct association was found between any the GPS / accelerometer data with the subjective measure of load through sRPE. In summary, the study was unable to determine GK training caused NMF and found no significant relationship between GPS / accelerometer variables and sRPE.