The tongue acts more like a conveyor belt – and less like the lapping tongue of a cat – as the bat feeds on flowers.

Chemically speaking, you become a different person when you run, according to new research in Science Translational Medicine that maps how chemicals change in the blood during exercise.

The study, by Gregory Lewis and colleagues from Massachusetts General Hospital, identified chemical switches in the body that are distinctly different during exercise in more-fit people versus less-people.