Grace Wade in New Scientist:
Motivation to exercise may come from the gut in addition to the brain. A study in mice finds that certain gut bacteria can increase the release of dopamine during physical activity, which helps drive motivation.
Though most of us know that exercise comes with many benefits, how much people exercise varies widely, says Christoph Thaiss at the University of Pennsylvania. He and his colleagues wanted to identify physiological factors that may explain this variation.
They collected data from 106 mice on exercise capacity, genetics, gut microbiome composition and more, and fed it to a machine learning model for analysis. The model found that how often mice exercised was most strongly associated with the makeup of their microbiome.
More here.