Sunshine is good for health and sport

The summer season brings with it light clothes, holidays and lots of sunshine as long as the anticyclone of the Azores allows anyway. Many of us will be sporting a tan or even a little pink or red. Tanning gives us a healthy glow and even seems to slim us, but the benefits of the sun on our health are not only aesthetic: sunlight in fact has a major impact on our health and our sports performance.

The issue of vitamin D

The belief that exposure to the sun increases sports performance is widespread among sportsmen and coaches. At the beginning of the twentieth century, it was said that athletes resorted to UVB radiation to improve performance compared to their opponents. Several studies have partially confirmed this belief, identifying vitamin D receptors in various organs and parts of the body, including muscle tissue.

Among the fibres most receptive to the action of this vitamin, we find the type 2 muscle fibres (or white fibres) that are involved in maintaining balance and rapid contraction of short duration. They are more responsible for anaerobic work: those who have large numbers of them excel in power sports. These fibres store the energy that is then released for short, explosive and high-intensity activities. Even during aerobic sports, adequate levels of vitamin D generate positive effects: among them the reduction of heart rate and the improvement of tissue oxygenation. Last but not least, vitamin D is able to slow down the loss of muscle mass during the aging process.

However, studies carried out in various parts of the world have shown that many sportsmen and women suffer from a lack of vitamin D. The consequences are manifold, here we cite the most significant: decrease in muscle strength, inability to sustain intense training, joint pain and increased incidence of stress fractures.

Vitamin D is a valuable ally for our overall health, not just for sports. The beneficial effects on bones and teeth are now well established, as is our ability to protect ourselves against cancer. New research now indicates that exposure to the sun stimulates other valuable substances: nitric oxide that protects our cardiovascular system, and serotonin, the "good mood" hormone. Scientists are finding that sunbathing can also help us keep us thin and healthy. The results show how ultraviolet rays can block the development of obesity and some symptoms of type 2 diabetes. These benefits were still independent of the effects of vitamin D and it is plausible that these effects are a result of the sun-drenched production of nitric oxide. The hypothesis is that without certain levels of nitric oxide in the bloodstream, insulin cannot work properly, favouring the onset of diabetes!

The sun as a source of vitamin D

This important vitamin is produced only in the presence of high volumes of exposure to the sun; in most countries it is produced mainly in summer, from June to August. In order to reach adequate levels of vitamin D it is important to expose your hands and face to the sun all year round, when weather conditions allow, especially taking advantage of the months from April to October: in winter it would be enough to expose yourself to sunlight at least 10 minutes a day to maintain an optimal level of vitamin D.

If the sun is not there, UV rays can penetrate the clouds and therefore the activation and absorption of vitamin D will take place anyway, albeit to a lesser extent. With this we are not suggesting that we expose ourselves to the sun to excess, especially in the warmer months. We know very well that excessive exposure to UV rays is harmful.  If you are in the sun for a long time, it is best to protect yourself with glasses and sun creams suitable for your phototype.

Last but not least: the sunscreen

The first protective cream was designed in the 1930s by Franz Greiter, a Swiss mountaineer who was a chemistry student and after having blanched himself during the conquest of Piz Buin, decided to develop specific skin protection for his face to be used for excursions at high altitudes.

Today's creams are very different from the ancestors of the 30s, today the identity of the effective cream is: fragrance-free, in large packaging and with clearly legible labels. They must contain latest generation filters with high stability (mexoryl, tinosorb, uvinul). Possibly in large packages because, to be really effective, the sun creams must be spread evenly throughout the body in abundant measure continuously renewing the application during the day. According to experts, the right amount is 40 grams of product for every hour of exposure to the sun.

When it comes to legible labels, we cannot help but mention the Sun protection factor. Generally, this number is prominently positioned on packs of sunscreen. This number indicates the capacity of sun filters to protect against UVB radiation, the most dangerous, because it is responsible for skin burns. To calculate the skin protection factor, the reddening times of skin protected by sunscreen and unshielded skin are compared.

The protection capacity of a sunscreen does not increase linearly as the SPF increases: in other words, an SPF 30 is not twice as effective as an SPF 15. When used correctly, the former shields 97% of UVB rays, the latter 93%. Most dermatologists recommend creams with an SPF of at least 30 and even better if it is water resistant. This value, however, says nothing about protecting against UVA rays that penetrate deep into the epidermis, causing it to lose elasticity and wrinkles. They also contribute to the risk of skin cancer. For this reason it is better to choose "broad-spectrum" solar filters.

At this point, admiring your already amber skin, you'll be wondering if you can do without the protection since you're already tanned. The answer is no, because the radiation protection power of already tanned skin - that is, the melanin pigment - is much lower than the screen offered by sun creams. Even those who are already tanned risk getting burnt (if only because they worry less). And if you are already asking... creams with a high SPF do not make you tan less: rather, it is a slower tan, less traumatic to the skin and more durable.

Finally, a very important precaution on the conservation of these products: the sun and sand alter the properties of sun creams, which is why it is good not to use the creams of the previous year. If optimally stored, sunscreen products last for 12 months from the date of opening (period after opening shown on the labels). But considering we keep them on the beach, they can lose effectiveness in even less time.

There is a separate speech for the pool environment. Compared to seawater, the water in the tank is cleaner from a microbiological point of view but is more aggressive on the skin, especially because of the derivatives of chlorine. The aggressive action also concerns sun creams that suffer a loss of protective effectiveness.

A solar swimming pool must be photo stable, water resistant and chemically inert, a rare feature in commercial products. What does this last point mean? Many sun filters are decomposed by chlorine in the water and lose their ability to absorb UV-B and UV-A rays. In addition, sun protection is reduced with frequent baths: The so-called water-resistant solar baths are tested to withstand about 4 20-minute dives. The clutch of the towel also helps to remove the sun. The recommendation is therefore to take a shower after swimming in the pool and reapply the protection on the skin.

Finally, let's face the myth that chlorine "bleaches" our skin, causing us to lose our tanning effort: in reality, what happens is that, in the long run, this chemical in contact with the skin makes it drier, accelerating the process of exfoliation of the outer layers of the epidermis. This can be remedied by applying a few simple measures.
Dry in the sun. It is one of the most effective remedies because the sun's rays counteract the effects of chlorine and are also a way to "refresh" your tan.
Use waterproof solar. These products do not dissolve in water and allow to create a protective layer on the skin against chlorine.
Take a shower. At the end of the day in the pool it is better to prefer a quick shower with not too hot water. Too much immersion in water accelerates the detachment of dead cells that carry away your tan. Moreover, it is advisable to use neutral detergents to avoid damaging the epidermis and, at the end, dry gently and dab with a towel.
Always be hydrated. To avoid losing your tan, your skin should always be hydrated. Spread creams and moisturizing oils several times a day, but also take care of your diet by drinking plenty of water and favouring foods such as fruits and vegetables that contain a lot of liquids.