Are you one of those folks who wear shorts in winter, go swimming while everyone else is still wearing flak jackets, and who discovers they can handle winter camping with more comfort than their friends? If so, you may be one of the many people who have a genetic mutation associated with increased cold resistance, a benefit in cold climates, but which may come with a sacrifice in athletic performance.
The results came from the Karolinska Institute, which found that nearly one in five people have muscle fibers lacking alpha-actin 3. This mutation, which may have been beneficial in the distant past when humans migrated to cold regions, was found to help preserve a person. warm.
The protein is only found in rapidly twitching muscle fibers – and about 20 percent of the world’s population lack this protein as a result of a genetic mutation, according to the new study, the first study linking loss of this protein to increased cold resistance.
The results are based on a study of 42 healthy adult males who were tasked with sitting in 57 ° F water until their body temperature drops to around 96 ° F. An electromyography was used to measure the electrical activity in the participants’ muscles during this time. Also, muscle biopsies were taken to study fiber formation.
The results showed that the participants who lacked protein had slow-twitch muscle fibers, which enabled them to maintain body heat in a more efficient manner. While fast-twitch muscle fibers cause twitching, slow twitch fibers experience more basic contractions, which produce heat.
However, one big question remains: What effect does this have on exercise performance? While studying this aspect the researchers were difficult He explains:
People who lack α-actinin-3 rarely succeed in exercising that requires strength and bursting, while a tendency toward greater ability has been observed in these people in endurance sports.