Hairy Myths, Truths and Tips For Runners

As runners we are constantly faced with hairy dilemmas. But what most of us probably didn’t know is that every hairy patch we bear has a distinct function. And that almost all of these functions  can be related back to one of our primal features to survive as a species: our ability to run vast distances.

Nuisance or underappreciated for its benefits, here is the lowdown on hair that runners may find handy when considering that wax, trim or shave.

Hair, Hair Everywhere!

When it comes to mammals, our species are one of the least hairy ones on the planet. But this wasn’t always the case. Science tell us our early ancestors used to don full fur suits when they still foraged for fruits and tubers in the cool, shady forests of Central Africa.

It is hypothesized that, when forest turned savanna as brought about by a drier climate, the furry coats became too hot for the early hominids that had to start running far and long after their next meal. Most of the body hair was lost through a process of natural selection.

Why then, we may ask, did some dense patches of hair remain? And that soft peachy fuzz that covers large parts of our bodies? Is it a myth or may it be true that bodily hair in humans is purely vestigial, just like the human appendix and wisdom teeth?

The Functions of Bodily Hair

Contrary to the myth, all human bodily hair has a clear and useful function. 

Vellus hair

The short, light colored hair that covers the largest parts of a person’s body and develops in childhood is called vellus hair. These hairs can be found almost everywhere except for places such as the lips, the back of the ears, hand palms, inside the navel or on the soles of the feet. Vellus hair is replaced with thicker hair with the onset of puberty.

Vellus hair aids the body in thermoregulation. When it is cold the hair stands erect to trap warm air close to the body. When it is hot, vellus hair helps the body to cool by acting as a wick for sweat which then evaporates and cools the body off.

Terminal hair

During and after puberty, vellus hair is supplemented by coarser, more pigmented terminal hair. These hairs are sensitive to the male hormone androgen and is therefore also termed androgenic hair. It grows longer on the genitals and in the armpits, and on the male face and sometimes chest, arms and legs.

Two types of sweat glands occur in the thicker, hairier patches such as those occurring in the armpits and in the genital area. The first type is the normal type that aids with thermoregulation, called eccrine glands. The second type of sweat gland is called the apocrine sweat gland only occurs in these hairy regions. The denser hair hold on to the sweat longer and then disperse it. It is said to serve dual purposes. Firstly, our natural bodily odor attracts potential mates, contrary to what the deodorant industry would want us to believe. And secondly it also acts as protection against friction. Hair protects the thighs and armpits during running and the pubic area during  intercourse.

Other Hairy Patches and their functions

• Eyebrows keep sweat from running into the eyes. Sweatband anyone?
• Second only to head hair, nose hair is the densest hair on the human body. It serves as a filter to prevent foreign particles from entering the airways. So sign right up for the Marathon des Sables, we are naturally geared for a dust storm.
• Similarly, eyelashes also protect the eyes from debris but also function as a sensory organ, similar to a cat’s whiskers. Eyes will close reflexively when the lashes senses a possible harmful intrusion.  

About Head Hair

So why, when most other hair on our bodies became shorter, do we still bear long growing hair on our heads? The main reason for our head cover is said to be protection from UV rays. In addition, it also helps with thermoregulation. Similar to vellus hair, head hair traps heat in the cold or wicks sweat when it is hot.

Myth Buster

Is it true that humans lose most body heat through their heads? This is a myth that probably arose during rudimentary experiments carried out by U.S. military researchers in the 1950’s. The results of a 2008 study suggests that only about 7 to 10% of body heat is lost through the adult head. This percentage is proportional to the total body surface the head represents. In babies this percentage increases due to less hair coverage and also the relative large size of the head compared to the rest of the body.

Hair Color as Health Indications and Tips for Runners

Besides the old adage that ‘blondes have more fun’, there are loads more that is signified by the natural color of one’s hair.

• Blondes usually have more hair than brunettes. This is because blondes produce less melanin, the pigment that protects the skin from UV rays, and thus need more hair to protect their heads.
• Blondes, especially those with blue eyes are more at risk eye diseases caused by UV rays, so good eye protection is recommended before heading out on the run.
• Similar to blondes, redheads are also more vulnerable to UV damage than brunettes. A good sunblock and hat is recommended for all runners, but especially to the fair skinned- and haired.  

In a Nutshell

Now that we know that our hairy bits are an ally, we may reconsider our waxing and shaving habits. More hair means better thermoregulation, both in cool and warm climates. Also, less bodily hair removal means less painful chafing. This will help, especially in the nether regions, where ingrown hairs can ruin a run. Still struggling to find a mate? Then do forgo the deodorant before your next club run. Science has been right a few times before…