Letter to the Editor regarding the article “A 4-week endurance training program improves tolerance to mental exertion in untrained individuals”

According to the psychobiological theory model,5 any factor that affects the rating of perceived exertion (RPE) and motivation will, in turn, affect performance. [...]once motivation was similar between groups, we should closely observe what caused the differences in the RPE. [...]Filipas et al.1 showed no differences in perceived general and mental fatigue (e.g., fatigue, mental fatigue, and motivation) or cognitive scores. [...]it seems the effects on performance were due to the physical training and not related to increased resistance to mental fatigue. [...]it is our view if any resistance to mental fatigue was built up due to physical training, clear changes in cognitive performance or feelings of mental fatigue should have been observed. [...]it seems entirely rational to assume that performance improvements were observed because of peripheral adaptations to training.