Swimming is a sport that is attracting an increasing number of enthusiasts, whether it's for occasional wellness, regular training, or professional-level discipline. Muscle strengthening, improved respiratory capacity, low impact on joints... It's true that swimming has a lot to offer. However, despite its benefits, swimmers face a common skin problem: the xerosis. Characterised by rough skin, tightness, and even flaking and cracking, this condition results from an impairment of the skin barrier function, due to significant water loss and disorganisation of the protective lipids in the stratum corneum. Although xerosis can affect anyone, swimmers are particularly at risk.
An alteration of the skin barrier by water.
Contrary to what one might think, immersing one's body in water does not hydrate the skin, quite the opposite in fact. Let's remember that the epidermis is naturally protected by a hydrolipidic film, a semi-aqueous, semi-oily mixture, which helps to limit the entry of pathogens into the skin and the evaporation of water from the epidermis. This function is also fulfilled by the lipids of the stratum corneum, the most superficial layer of the epidermis. This layer is composed of a mixture of ceramides, fatty acids and cholesterol, organised into lamellar bilayers. When the skin is immersed for too long, the hydrolipidic film, as well as the lipid structure of the stratum corneum, gradually dissolve and become disorganised.
Swimmers who spend several hours in the water therefore undergo repeated aggression to their skin barrier. With each immersion, the protective lipids are gradually eliminated, leaving the skin more vulnerable. Over time, this alteration can lead to a dry skin condition.
A dehydrating effect of chlorine.
For health reasons, swimming pool water is treated with various chemical agents, including chlorine. While this disinfection is crucial to prevent the proliferation of bacteria and fungi, it is not without consequences for the skin. Indeed, chlorine is an oxidising molecule that works by breaking down organic impurities present in the water. However, it does not limit itself to external contaminants: it also interacts with the lipids in the skin, contributing to their degradation.
Frequently exposed to chlorinated water, the skin of swimmers gradually sees its hydrolipidic film diminish, thereby altering its barrier. Moreover, chlorine has an irritating effect that can cause inflammation and exacerbate the sensation of dryness and xerosis. This action is even more pronounced in individuals with sensitive skin.
Rapid evaporation of water after the swimming session.
After a swimming session, the skin often starts to feel tight. This phenomenon is even more pronounced in indoor pools, where the hot and dry air from ventilation systems accelerates dehydration. As it evaporates, the water present on the skin's surface carries with it the water from the inner layers. This weakens them, especially as they have already been compromised by prolonged contact with chlorinated water.
For individuals who swim outdoors, xerosis is exacerbated by other factors, starting with exposure to UV rays, which generate oxidative stress. By promoting the production of free radicals in the skin, UV rays disrupt the stratum corneum. Indeed, free radicals react with lipids in a process known as lipid peroxidation. This generates inflammatory by-products, such as the superoxide anion, which can damage skin tissues and DNA. In addition to UV rays, outdoor swimmers are exposed to wind, which also contributes to xerosis by accelerating the evaporation of water from the skin.