When those colder months come around, you can guarantee there will always be that one person who is always cold, even when they wrap up in huge jumpers and thick coats. But you also get that person who still complains about being hot even if it’s freezing cold. It’s interesting to know that this is in fact due to each person’s genetic structure.
The human body’s resistance to cold depends on the cells found in the muscle. ‘A muscle cannot function without producing heat,’ says Daniel Ricquier, a biochemistry professor at Paris-Descartes University. This simple piece of information will help you understand the rest.
Alpha-actinin-3: the protein that makes the difference
The Karolinska Institutet in Sweden did a study on this. They made multiple men float in cold water, so they could study the electrical activity of the muscles.
Why did they do this? In order to understand why some people are more sensitive to the cold than others. The answer is quite simply alpha-actinin-3, the protein that may be present or absent in our muscles.
If your muscles are missing alpha-actinin-3, then you will be less likely to feel the cold. Why? Because your muscles contract slowly, which means less energy is spent, leading to better resistance to the cold. If you are in possession of alpha-actinin-3, your muscles contract quicker, making you feel the cold a lot more.
Marathon runner or a sprinter?
This protein can also make a difference in sport. For example, if your muscles contract quickly, you will be better suited for shorter intense sports whereas if you have slower contracting muscles, you should favour sports that require endurance.
In simpler terms, a marathon runner will less likely be affected by the cold compared to a sprinter.
It is estimated that alpha-actinin-3 appeared 80,000 years ago when the Homo sapiens travelled from Africa to Europe, where the weather was much colder, meaning the body had to adapt. How incredible is the human body?
Three other explanations
This protein isn’t the only explanation for why some people feel the cold more than others. Here are three other reasons why.
1/ Your metabolism
If you have a relatively fast metabolism, your body will use more energy, heating your muscles, which then leaves you feeling less cold. This is also true for those who have a good blood flow.
2/ Body fat
Body fat, or to use its scientific name: adipose tissue, is an excellent protector from the cold as it provides an extra layer of protection.
3/ Men and women
The feeling of cold is regulated by the testosterone hormone, which is more abundant in men than it is in women. This means that it can be more common for women to feel the cold more than men.