Caffeine and placebo improved maximal exercise performance despite unchanged motor cortex activation and greater prefrontal cortex deoxygenation - Pires, Flavio O; Anjos, Carlos A. S. dos; Covolan, Roberto J. M; Fontes, Eduardo B; Noakes, Timothy D; Gibson, Alan St Clair; Magalhães, Fernando Henrique; Ugrinowitsch, Carlos (Frontiers in physiology, 2018)