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Shiseido discovered that protecting the skin from ultraviolet rays using sunscreen etc. reduces fatigue and helps with subsequent recovery

~ The degree of sunburn and the feeling of fatigue show a correlation, confirming the importance of UV protection ~

Shiseido scientifically verified the effects of exposure to ultraviolet rays during outdoor exercise on the mind and body, and confirmed in this experiment that protecting the skin from ultraviolet rays using sunscreen etc. reduces fatigue during exercise and up to 24 hours after exercise. It was discovered that there is a correlation between the degree of redness of the skin due to sunburn and the feeling of fatigue, and it was also revealed that there is a possibility that the way muscle pain is felt after exercise may be reduced by using sunscreen. In other words, this shows the possibility of being even more active under the sun by incorporating UV protection such as sunscreen into leisure, sports, and daily life. This research is a joint study with Dr. Nobuhiko Eda, Lecturer at Dokkyo Medical University Basic Medical Education Division/Waseda University Sports Science Research Center Guest Researcher.
By applying the results of this research, we will proceed with the development of products and services that realize a future where customers can enjoy their daily lives actively, freely, and under the sun.
Some of the results of this research were presented at the 75th Annual Meeting of the Japanese Society of Physical Fitness Medicine held online from 2020/9/24 to 26.

Figure 1. By protecting the skin from ultraviolet rays with sunscreen, etc., it is possible to reduce fatigue during and after exercise (image)

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Figure 2. Fatigue felt after exercise is reduced in groups using sunscreen

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Figure 3. There is a possibility that the way muscle pain is felt will become lighter in groups that use sunscreen

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Research background

I think there are many people who have experienced feeling tired from going out under the scorching sun or exercising outdoors. In fact, the effects of ultraviolet rays and excessive exercise on the mind and body have gradually been clarified, but until now it has not been sufficiently verified what kind of changes occur in the effects on the mind and body by protecting against ultraviolet rays.
Therefore, this time, we scientifically verified the effects of UV exposure and UV protection during outdoor exercise on the mind and body, and proceeded with research with the aim of searching for a method with high performance and even more active activities under sunlight.

The feeling of fatigue is reduced by applying sunscreen

Sixteen healthy male and female adults were divided into 2 groups with and without UV protection, and tests were conducted in Okinawa. The group with UV protection applied a sunscreen formulation (SPF50+, PA++++, super waterproof) developed by Shiseido to the skin, and the group without UV protection applied a base with no sunscreen effect, which removed the UV absorber/scattering agent from the sunscreen. A shuttle run-style exercise (performed in 4 sets for 60 minutes) was performed outdoors, and the concentration of blood lactate value*1, which is one of the factors related to blood fatigue, subjective exercise intensity, and how muscle pain is felt were investigated.
As a result, in this experiment, it was found that the redder the skin, which indicates the degree of sunburn, the greater the feeling of fatigue after exercise (Figure 4), and that groups without UV protection tend to feel fatigue more easily compared to groups with UV protection (sunscreen application) (Figure 2). Furthermore, blood lactate levels increased significantly immediately after exercise in the group without UV protection (Fig. 5). Furthermore, it has been confirmed that the amount of change in redness of the skin after exercise is proportional to the amount of change in blood lactic acid levels and the amount of change in oxidative stress during exercise, and from the above results, it was inferred that the feeling of fatigue during exercise can be reduced by protecting the skin from ultraviolet rays using sunscreen.
*1 Lactic acid is a product formed by metabolizing and breaking down carbohydrates in glycolysis (anaerobic metabolism), and when muscles make energy, sugar (glycogen) is broken down and produced. During exercise, the lactic acid produced is reused as an energy source, but it is known that it accumulates after strenuous exercise, and it is possible to estimate the degree of fatigue due to exercise by examining blood lactate levels.

Figure 4. The degree of sunburn (redness of the skin) correlates with the feeling of fatigue

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Figure 5. The group that used sunscreen suppresses an increase in blood lactate levels immediately after exercise

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There is a positive trend in performance during exercise and recovery after exercise due to the application of sunscreen

As for subjective exercise intensity (tightness), it was found that the group with UV protection (using sunscreen) showed a lower value in the latter half of exercise (from Set 3 to Set 4) compared to the group without UV protection, and it was found that they tend to be less likely to feel tightness even in the latter half of exercise (Fig. 6). Since subjective muscle pain showed a significant increase after 24 hours only in the group without UV protection, it was suggested that general muscle pain after exercise can be suppressed by protecting against ultraviolet rays (Fig. 3). There was also a tendency for fatigue 6 hours and 24 hours after exercise to be lower in the group with UV protection (using sunscreen) (Figure 2).
From these results, it was suggested that protecting against UV rays has a positive effect on performance during exercise and recovery after exercise.

Figure 6. Toughness felt during exercise is reduced in groups that use sunscreen

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Future prospects

In this study, it was scientifically shown that mental and physical damage can be suppressed by protecting the skin from ultraviolet rays, and it was suggested that UV protection such as sunscreen not only maintains the beauty of the skin, but also supports active activity under the sun.
Going forward, we will continue to further accelerate the development of UV protection technology, starting with sunscreen, based on knowledge and technology in basic research areas where we are strong, and advance the development of products that can enjoy the benefits of the sun even more by preventing ultraviolet rays with advanced technology. Furthermore, in addition to making products that take the global environment into consideration, we are also actively working on social contribution activities, such as carrying out educational activities to spread understanding of ultraviolet rays and sunscreen to children. Shiseido will continue to support the healthy, beautiful, and shining lives of people around the world under the sun.

*Please note that the information described in this release is current at the time of publication and may differ from the latest information.