Does overtraining cause mitochondria to dysfunction? We look at data in the Flockhart study on excessive training and compare them to the headlines, a similar overtraining study using proteomics, and a published response to Flockhart. We break down mitochondrial function, what various measurement methods actually tell us, why your mitochondria are probably just fine, and why these studies raise more questions about mitochondria's role in overtraining (if any) than they answer. Finally, we answer your listener questions on the Flockhart study, mitochondrial function, and overtraining.