Exercise Training Prior To and During Cancer in Mice Preserves Muscle Mass, Reduces Tumor Weight, and Suppresses Molecular Mediators of Cachexia

Muscle mass adaptations related to running volume; and running distance relative to controls was not appreciably reduced by tumor status. Tumor burden was reduced after ~11.5 weeks of PoWeR compared to sedentary, but this was not explanatory for muscle adaptations. PoWeR induced a faster-to-slower muscle fiber type transition in the gastrocnemius and suppressed key protein turnover markers (Redd1, Murf1, Atrogin, Ubc, Gadd45a) as well as the mitophagy-related marker Bnip3 in tumor-bearing muscle; 24h muscle protein synthesis remained stable.

PoWeR counteracted tumor-induced impairments in the muscle mitochondrial- and metabolic-related transcriptome. Collectively, physical activity prior to and during cancer preserves muscle mass, reduces tumor growth, and mitigates molecular drivers of CC, underscoring its preventive and therapeutic potential as a lifestyle intervention.