HealthCert Blog

Sunscreen is an important tool in protecting the skin against sun damage, which can cause complications such as pigmentation, wrinkles and skin cancer. Sweat-resistant sunscreens are recommended for patients who are outside on hot summer days or who do physical activity outdoors, so that sweating will not remove or compromise the protection. But do sweat-resistant sunscreen products impede natural sweating?

Sweating plays a critical role in maintaining thermal balance and keeping skin cool during exercise. A study looked at whether wearing sweat‐resistant sunscreens might impede natural sweating, potentially interfering with thermal regulation and resulting in the elevation of skin temperature.

In the study, 24 female subjects wore an SPF 70 lotion sunscreen on half of the face and an SPF 70 spray sunscreen on one of the forearms at a dosage of 2 mg cm⁻². Following application, subjects participated in two sessions of indoor exercise to induce clearly visible sweating.

It was found that both skin temperatures and sweat evaporation rates were significantly elevated after each session, yet there were no significant differences in either skin temperatures or sweat rates between the treated and untreated control sites at any time point for any of the skin sites measured.

The study concluded that applying sweat‐resistant sunscreen lotions and sprays has no measurable effects on skin cooling by natural sweating process. It recommended that patients should continue to use these sunscreens during recreational activities, and that physicians should continue to encourage regular application of sweat-resistant sunscreen products.

Read more recent research.

Source: Ou‐Yang, H. , Meyer, K. , Houser, T. and Grove, G. (2018), Sunscreen formulations do not interfere with sweat cooling during exercise. Int J Cosmet Sci, 40: 87-92. doi:10.1111/ics.12440

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