Mice given MOTS-c burned more sugar for energy and produced more body heat—even though they didn’t move around more than the control mice.

MOTS-c injections made mice burn more glucose instead of fat, as shown by higher CO2 output relative to oxygen use.

MOTS-c didn’t make mice move more, so its effects on weight and metabolism aren’t just because they were exercising more.

MOTS-c made muscle cells produce more GLUT4 (a sugar transporter) and turned on AMPK (an energy sensor), two key players in how muscles use sugar.