endurance athlete Adult 1 Article 1 Athletes 1 Brain Stem 1 Cerebral Cortex 1 Connectome 1 Humans 1 Magnetic Resonance Imaging 1 Male 1 Pain Measurement 1 Pain Perception 1 Thalamus 1 Young Adult 1 adult 1 anterior cingulate 1 athlete 1 brain cortex 1 brain region 1 brain stem 1 clinical article 1 comparative study 1 connectome 1 controlled study 1 correlation analysis 1 dehydration 1 diagnostic imaging 1 dorsolateral prefrontal cortex 1 endurance sport 1 exercise-heat stress 1