Motorcycling performance and sleepiness during an extended ride on a dynamic simulator: relationship with stress biomarkers

Abstract Objective : Powered two-wheelers (PTW) make up a large proportion of fatal accidents. The aim of this study was to investigate the effects of time-of-day and total sleep deprivation (SD) on simulated motorcycling performance during extended riding sessions (60 min), while evaluating stress mechanisms. Approach : A total of 16 healthy males participated in four simulated motorcycling sessions at 07:00, 11:00, 15:00 and 19:00, including city (8 min), country (2 min) and highway pathways (40 min), after a normal night of sleep and after total SD (30 h), in a randomized counterbalanced order. The recorded motorcycle parameters included: variation of lateral position, number of inappropriate line crossings (ILC), falls, riding errors, speed and speed limit violations. Subject parameters included the number of microsleeps in each pathway, the number of lapses during the 3-min psychomotor vigilance task (PVT—Brief version), and the Karolinska sleepiness scale (KSS) score. Saliva samples were used to assess cortisol (sC), α-amylase (sAA), and chromogranin-A (sCgA). ANOVAs and Pearson’s correlation analysis were performed between these variables. Main results : Most parameters were influenced by an interaction effect between ‘Motorcycling pathways’ × ‘SD’ (speed ( p