Intense long‐term training impairs brain health compared with moderate exercise: Experimental evidence and mechanisms. Issue 1 (18th October 2022)

• Record Type: Journal Article
• Authors: Sangüesa, Gemma; Batlle, Montserrat; Muñoz‐Moreno, Emma; Soria, Guadalupe; Alcarraz, Anna; Rubies, Cira; Sitjà‐Roqueta, Laia; Solana, Elisabeth; Martínez‐Heras, Eloy; Meza‐Ramos, Aline; Amaro, Sergi; Llufriu, Sara; Mont, Lluís; Guasch, Eduard
• Is Part Of: Annals of the New York Academy of Sciences. Volume 1518:Issue 1(2022)
• Page Start: 282
• Page End: 298
• Publication Date: 2022-10-18
• Subjects: brain connectomics -- cognition -- endurance exercise -- mitochondria -- physical activity load; Medical sciences -- Periodicals; Medicine -- Periodicals; Science -- Periodicals; 610
• DOI: 10.1111/nyas.14912
• Languages: English
• ISSNs: 0077-8923

Abstract

Abstract: The consequences of extremely intense long‐term exercise for brain health remain unknown. We studied the effects of strenuous exercise on brain structure and function, its dose‒response relationship, and mechanisms in a rat model of endurance training. Five‐week‐old male Wistar rats were assigned to moderate (MOD) or intense (INT) exercise or a sedentary (SED) group for 16 weeks. MOD rats showed the highest motivation and learning capacity in operant conditioning experiments; SED and INT presented similar results. In vivo MRI demonstrated enhanced global and regional connectivity efficiency and clustering as well as a higher cerebral blood flow (CBF) in MOD but not INT rats compared with SED. In the cortex, downregulation of oxidative phosphorylation complex IV and AMPK activation denoted mitochondrial dysfunction in INT rats. An imbalance in cortical antioxidant capacity was found between MOD and INT rats. The MOD group showed the lowest hippocampal brain‐derived neurotrophic factor levels. The mRNA and protein levels of inflammatory markers were similar in all groups. In conclusion, strenuous long‐term exercise yields a lesser improvement in learning ability than moderate exercise. Blunting of MOD‐induced improvements in CBF and connectivity efficiency, accompanied by impaired mitochondrial energetics and, possibly, transient local oxidative stress, may underlie the findings in intensively trained rats. Abstract : The consequences of extremely intense long‐term exercise for brain health remain unknown. We studied the effects of strenuous exercise on brain structure and function in rats that were assigned to moderate (MOD) or intense (INT) exercise or a sedentary (SED) group. INT yields a lesser improvement in learning ability compared to MOD and blunts MOD‐induced improvements in cerebral blood flow and connectivity efficiency.