[[alternative]]The Study of the Effects of Applying Different SPF Sunscreens on VO2max and Skin Physiological Qualities along with sun protection

[[abstract]]Ninety percent of south Taiwan male students didn’t apply sunscreen (SS) when exercising in the sun. Besides, thirty-five percent of them think that apply SS would interfere their exercise performance and reduce skin qualities. Therefore, the purpose of this study is to compare the differences of selected skin qualities and erythema among subjects with or without SS while sit still or trying maximal oxygen uptake test (VT) under ultraviolet B (UVB) light. The differences of VO2max among subjects with sun protection factor (SPF) 15, SPF90, placebo (P), or nothing (N) （the four lotions） are also evaluated. Ninety-six skin type III or IV male students (age20±1.9 yr) were selected for the study. Thirty-six of them wearing the clothes with seven squares (2cm x 2cm ) holes on the back were divided into 6 groups. Each subject in each group was applied two of the four lotions on either side of their backs while sitting still 10 minutes under 0.08mj/cm2 UVB. Then erythema (E), skin water conent (SWC), skin sweating rate (SSR), trans-epidermal water loss (TEWL), skin aging (SA), and skin elasticity (SE) were tested on either side of the subjects’ backs. Dependent t-test is used to analyze acquired data. Another 36 subjects were also divided into 6 groups (the same as above) while trying VT under 0.08mj/cm2 UVB. Acquired data were analyzed by dependent t-test. Two weeks later the other 24 subjects trying VT with vest only again were divided into 4 groups. Each subject in each group was applied one of four lotions on the skin uncovered. All of them try VT under 0.08mj/cm2 UVB, and their VO2max data were recorded. ANCOVA is used to analyze acquired data. Statistical results reveal that no matter sitting still or trying VT, there is significant difference in E between subjects applied SPF 90 SS and subjects applied SPF 15 SS、P or N. It also makes difference in E to apply SPF15 SS or apply P on subjects. Applying SPF15 SS or applying N on subjects as well results in different E. Besides, no significant difference in E has been found between subjects applied P and subjects applied N. Moreover, there is no significant difference in SWC, SR, TEWL, SA, SE, and VO2max between subjects applied SPF90 SS, and subjects applied SPF15 SS、P or N. It is concluded that whether applying sunscreen or not would not make difference in skin physiological qualities no matter subjects on sitting still or trying VT under a short period of exposing to ultraviolet light. However, applying high SPF sunscreen could give the skin better protection.