How are BDNF and Müdigkeit related?

The relationship between BDNF and fatigue is not conclusively established. BDNF supports neuronal health and is released during exercise; low levels have been linked to fatigue in some studies, but the provided context focuses on the BDNF Val66Met polymorphism and its interaction with exercise on mood, not fatigue directly. One large study found no interaction between this genotype and physical activity on depressive symptoms [PMID:24745471], while a smaller trial suggested Met carriers may benefit less from exercise for anxiety [PMID:27453731]. These findings do not directly address fatigue. Evidence is mechanistic and unclear. Consumer DNA tests claiming a link between BDNF variants and fatigue should be viewed skeptically; the effects are small and context-dependent. More research is needed to clarify any causal role.