Shivering Produces Exercise-related Hormone

Right now you may be cursing your student house and the five jumpers you have to wear inside to keep warm, but the cold might actually be helping you lose weight. Scientists have found that shivering causes the body to produce a hormone, irisin, which helps muscles stay warm. This hormone is also produced during exercise and causes the production of calorie-burning brown fat and improves metabolism.

Researchers from the National Institute of Diabetes and Digestive and Kidney Diseases were investigating healthy volunteers. They found that irisin was produced in proportion to shivering intensity and a similar amount of irisin was produced from shivering as from exercise. In addition, when the team exposed human fat cells to a precursor of irisin (FNDC5), the cells burned more energy and released more heat, showing the beneficial effect that this hormone could be having.

This suggests that producing irisin during exercise probably evolved from similar mechanisms to shivering (burning calories to increase heat). It explains why irisin (a hormone that makes the body feel hotter) is paradoxically produced during exercise. These findings could help treat obesity, as irisin could be exploited to mediate the relation between muscles and fat. So if your house is so cold it makes you shiver, take heart: it may mean you need to go to the gym less often.