INTRODUCTION: Paratrooper training courses are very demanding, leading to a high number of drop-outs, despite existing selection criteria. This study investigated physiological, neuropsychological, and subjective data of completers and drop-outs during paratrooper training to identify potential predictive indices.METHODS: Tested were 24 paratrooper soldiers before (t₀), after 8 wk (t₁), and at the end of a 12-wk training camp (t₂). There were 11 soldiers who completed the course and 13 dropped out. The Training OPtimalisation test (TOPtest) uses two maximum exercise events to assess changes in measured parameters. The TOPtest was administered at t₀, t₁, and t₂; physiological [i.e., adrenocorticotrophic hormone (ACTH), cortisol, heart rate (HR)], neuropsychological (Stroop, Flanker, Go NoGo, Task Switch), and subjective data [Profile of Mood States (POMS)] were collected. Physiological and subjective raw data was gathered pre- and post-test from each of the two maximum exercise tests. The pre/post-test change of each parameter’s raw values was calculated as the parameter’s reactivity (or delta score).RESULTS: At t₀, drop-outs showed a significantly smaller HR reactivity (117.9 ± 14.0 vs.107.7 ± 10.6). Delta scores of tension and fatigue values differed significantly between completers and drop-outs at t₀. Completers’ physiological reactivity during the TOPtest at t₂ (HR: 105.91 ± 13.68 vs. 95.55 ± 10.28) was significantly reduced and became comparable to the drop-outs’ reactivity at t₀. Delta scores of fatigue and tension values showed a similar pattern.DISCUSSION: Reactivity of HR, tension, and fatigue parameter values were found to have predictive value in identifying completers vs. drop-outs of an elite paratrooper training course.Vrijkotte S, Meeusen R, Roelands B, Kubesch S, Mairesse O, de Schutter G, Pattyn N. Refining selection for elite troops by predicting military training outcome. Aerosp Med Hum Perform. 2017; 88(9):850–857.