Mixed
Resistance training (RT) and aerobic training (AT) induce distinct molecular signaling pathways in skeletal muscle, with RT primarily activating mTORC1 to drive myofibrillar hypertrophy and AT primarily activating AMPK to drive mitochondrial biogenesis.
If your goal is to build muscle size, focus on resistance training to activate the mTOR pathway. If your goal is to improve cardiovascular endurance and mitochondrial function, focus on aerobic training to activate the AMPK pathway. Doing both simultaneously may blunt specific adaptations due to the 'interference effect' where AMPK suppresses mTOR signaling.
The mechanisms leading to a predominantly hypertrophied phenotype versus a predominantly oxidative phenotype, the hallmarks of resistance training (RT) or aerobic training (AT), respectively, are being unraveled... canonical signaling pathways (AMPK and mTOR) studied extensively in the context of AT and RT, respectively.
Why this rating
The paper is a comprehensive review citing numerous primary studies, but it does not present new primary data itself.
Source
Exercise-specific adaptations in human skeletal muscle: Molecular mechanisms of making muscles fit and mighty
Aaron C. Q. Thomas et al. · Free Radical Biology and Medicine · 2024
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