All that shivering from the polar vortex could actually be doing your body a favor.
A new study in the journal Cell Metabolism shows that when a person shivers, a hormone called irisin is released for the purposes of producing heat and maintaining body temperature through the stimulation of fat tissue. Irisin is also produced during exercise, and is thought to be responsible for many of exercise's health benefits. A big one: converting white fat to calorie-burning brown fat.
The study also showed that the amount of irisin secreted during shivering is similar to that secreted during exercise, and that the more a person shivers, the more irisin he or she secretes.
"Perhaps lowering the thermostat during the winter months could help both the budget and metabolism," study researcher Dr. Francesco S. Celi, of the National Institute of Diabetes and Digestive and Kidney Diseases, said in a statement.
In addition, the researchers noted that the findings suggest "exercise-induced irisin secretion could have evolved from shivering-related muscle contract," they wrote in the study. In other words, the findings could help to explain why the same hormone that is used to maintain the body's internal temperature in the cold is also produced during exercise -- and why people often feel hot from exercising.
Recently, a study conducted by Japanese researchers showed brown fat cell activity and number can be increased through exposure to cold (and consuming capsinoids, which are found in chili peppers).
Similarly, a study published earlier this year in the journal Trends in Endocrinology & Metabolism showed that consistently exposing yourself to mild cold could aid weight loss better than warmer environments.