Elite athletes are engaged in intensive physical training programs because it improves their physical strength and agility, but also to build endurance for resisting the negative impact of fatigue. Although it is well accepted that physical fitness can reduce the consequence of mental fatigue it is still unknown whether specific mental training can reduce the negative impact of physical fatigue on perceptual-cognitive functions. Here we show in professional rugby players that acute physical fatigue can dramatically reduce mental performance required for processing 3D-Multiple Object Tracking (3D-MOT) and that prior training, void of any physical demands, can build resistance to these detrimental effects.