Author(s): YAMAGUCHI, K., HOSHI, R.2, IMAI, A.2, NISHIYAMA, M.3, SHIRAMOTO, A.3, GOTO, K.2, Institution: RITSUMEIKAN UNIVERSITY, Country: JAPAN, Abstract-ID: 1366

INTRODUCTION:
Ultraviolet (UV) radiation reaching to the Earth’s surface has increased globally over the past few decades [1]. Thus, athletes may be exposed to higher levels of UV radiation during training and competition. Excessive UV exposure induces skin inflammation (erythema) and increases the production of reactive oxygen species [2]. Since inflammation and oxidative stress lead to central fatigue [3,4], UV exposure may exacerbate fatigue development and impair exercise performance. UV-protective clothing is a potential countermeasure against UV radiation [5]; however, it remains unclear whether UV-protective clothing mitigates UV-induced inflammation, oxidative stress, and fatigue. As a preliminary investigation, the present study aimed to investigate the effects of UV-protective clothing during passive sun exposure on skin blood flow, systemic oxidative stress markers, and perceptual fatigue.
METHODS:
In a randomized, crossover design, eleven healthy males completed three experimental trials consisting of 2-h passive sun exposure while wearing a sleeveless shirt with 65% UV protection (65%SL), a long-sleeved shirt with 65% UV protection (65%LONG), or a long-sleeved shirt with 99% UV protection (99%LONG) on separate days. Participants also wore the same hats, sunglasses, long tights, and shorts (all > 99% UV protection) during all trials. Heart rate and chest and forearm skin temperature were monitored during sun exposure. Chest and forearm skin blood flow, plasma oxidative stress markers, and perceptual fatigue were measured at baseline, immediately after, and 3 h and 6 h after sun exposure.
RESULTS:
During 2 h of sun exposure, heart rate and chest skin temperature did not differ among trials, whereas forearm skin temperature was significantly higher in 65%SL (38.0 ± 0.5 ℃) compared with 99%LONG (36.1 ± 0.2 ℃, P < 0.05). Forearm skin blood flow was significantly increased from baseline to 6 h after sun exposure only in 65%SL (+96.4 ± 39.1%, P < 0.05) and it was significantly higher in 65%SL (3.2 ± 0.8 ml/min/100g) compared with 65%LONG (1.6 ± 0.2 ml/min/100g) at 6 h post-exposure (P < 0.05). No significant difference was observed in plasma oxidative stress markers and perceptual fatigue among trials.
CONCLUSION:
Long-sleeved shirts with both 65% and 99% UV protection prevented an increase in forearm skin blood flow, suggesting attenuated UV-induced skin inflammation. In future, the effects of UV-protective clothing during outdoor exercise need further investigation.
References:
1. Feng F, Ma Y, Zhao Y, Wan Z, Zhang R, Yang S. Sci Rep 2025, 15: 39300.
2. Tang X, Yang T, Yu D, Xiong H, Zhang S. Environ Int 2024, 185: 108535.
3. Vargas NT, Marino F. Sports Med, 44: 1479-1487.
4. Morris G, Berk M, Walder K, Maes M. BMC Med 2015, 13: 28.