Running In The Sun: Everything You Need To Know

Running In The Sun: Everything You Need To Know

You might assume that running in the sun is a bad idea. The risk of cancer, premature aging, age spots, burns, tan lines – surely the joy and even benefits of running in the heat can’t be worth these risks.

Well, you might be surprised. Research reveals that, if done correctly, and if the proper measures are taken, running in the sun is actually very good for you.

So let’s explore.

The Cons of Running in the Sun

First off, some sun exposure is a good thing – it’s even recommended. The ultraviolet B (UVB) rays emanating from the sun provide your skin cells with the energy they need to start the process of vitamin D synthesis. Once produced in the body by the body, vitamin D helps you to absorb calcium, which is good for your bones. Without vitamin D, calcium absorption is just not possible.

But as it with any good thing, too much of it exposes you to a plethora of risks which range from aesthetic nuisances to serious, and even fatal, maladies.

The Dangers of UV Rays

Those same UVB rays that promote vitamin D production also pose grave threats to the health of your skin if exposed to in excess. What’s worse is that UVB rays are just one of two types of UV rays emitted by the sun. The other type is called ultraviolet A (UVA).

UVA rays account for almost 95% of the total radiation that actually reaches the earth’s surface. This is because they’re they have the longest wavelength of all forms of UV radiation (there is also what’s known as a UVC, but that’s a man-made type and has nothing to do with the sun). And research shows that UVA rays cause premature aging – things like wrinkles and age spots. It does this by entering the epidermis (your skin’s outermost layer) and damaging cellular DNA. Furthermore, UVA rays are emitted at equal intensities all the time; this is true even when it’s cloudy and the sun is blocked.

But UVB rays are different. They’re the primary cause of sunburn, skin reddening, and skin cancers. The intensity with which they’re emitted by the sun depends on your location and the time of day. In the U.S., generally speaking, UVB emissions peak around mid-day. So if you’re planning on running in the sun, you may want to heed this warning and plan accordingly.

Want to learn more about UV radiation and exactly how it causes cancer and premature aging? Check out the video below.

Some additional facts: 

  • A study published in Archives of Dermatology (now called JAMA Dermatology), found that, compared to the general population, marathoners have more age spots and abnormal moles. This means that they are more at risk of developing malignant melanoma.
  • Not only does running in the sun for long periods expose one to the risk of age spots and abnormal moles, but long periods of intense exercise just by itself, indoors or outdoors, can actually serve to make the skin more vulnerable to damage. This is because intense exercise – like that required for marathon training – actually suppresses the immune system.
  • In addition to the more serious maladies like melanoma, a weaker immune system also increases susceptibility to blisters and chafing.

The Pros of Running in the Sun

But there are some good things associated with running in the sun – despite the dreary picture we just painted.

The first benefit to it is one we’ve already briefly discussed. Vitamin D. We said earlier that vitamin D promotes stronger bones by allowing for calcium absorption. That’s one benefit.

But we didn’t say a word about what happens when you’re deficient in vitamin D.

Vitamin D deficiency has been linked to many conditions and maladies. Depression, prostate cancer, colon cancer, breast cancer, heart cancer, weight gain, and more, have all been found to be linked to vitamin D deficiency.

Conversely, it was found that people with high levels of vitamin D have a significantly lower risk of disease.

Nitric Oxide

Sunlight also has other health benefits. Our skin naturally harbors significant amounts of something called “nitric oxide,” a compound that serves to reduce blood pressure by dilating blood vessels; this in turn lowers the risk of strokes and heart attacks. Sunlight actually activates these compounds and releases them into your bloodstream.

Running in the Sun Could Make You Faster

That’s right – running in the sun may actually make you a faster runner. Research revealed in 2014 at the American College of Sports Medicine showed that cyclists actually saw an increase in speed after spending just 20 minutes exposed to UVA rays via a UVA lamp. This is attributed to the fact that nitric oxide, when released into the bloodstream, increases blood flow, which increases the amount of oxygen that flows into muscles.

More oxygen, better performance.

If you’re interested in learning more about nitric oxide and how it can help you improve your performance, check out the video below.

Staying Safe

Of course, even now that you know the benefits, you might still feel like you’re in the same position as when we began. Those benefits, you might think, don’t outweigh the plethora of risks you’d be facing.

And you’re right.

But that doesn’t mean you shouldn’t run in the sun. In fact, it’s a good thing – if and only if you take the necessary precautions. The first of which is to wear your sunscreen. 

It’s true that sunscreen does lower the amount of vitamin D your body will produce, but experts say that the difference isn’t drastic. You’ll still produce enough of it.

Another thing you should do is make sure you’re consuming enough antioxidants. In addition to their many benefits, antioxidants will help strengthen your skin’s defenses against sun damage.

And lastly, make sure you remain vigilant about any changes to your skin. Check for abnormalities yourself and visit your dermatologist at least once a year to check for skin cancer. If you feel the exposure is too strong, it’s wise to cover up with proper running clothing like sports arm sleeves and/or leg sleeves.

Do all these things with care and you can reap all the benefits of running in the sun while minimizing the risk.

And that’s all there is to it.


  1. Runner’s World
  2. WebMD