Discovered watching a Youtube video the other day you can get spf50 suncreams rated to last up to eight or ten hours, which seems perfect for cycling in Taiwan. Of the ones I looked up, I couldn’t find any apparently available in Taiwan.
Any cyclists have recommendations for suncreams spf50 I don’t have to reapply when out for six to ten hours on the bike? Something you can get in maybe Watsons?
A bit more expensive than what you can buy at Watsons or 7-11, but I’ve used it and it does stay pretty effective throughout the day:
Probably worth bringing it along with you on this really sunny days. Just in case.
From official website: Sunscreen, designed for athletes and for the harsh sun Alpine - Madform - Physio & Sport Products
I (barely) use Banana Boat Sport. I say barely because I mostly use thin long sleeve jerseys and thin leg covers. Plus gloves. So, the only skin I have exposed during peak sun hours is neck and face. And I do sometimes cover my neck too.
By applying strong sunscreen, you are robbing yourself of vitamin D, which is very important for health.
Vitamin D deficiency puts you into power saving, survival mode.
It seems, that is because of the evolutionary adaptation to the changing seasons.
In the winter, there usually is not much of food, so less UV light is signal, that winter is here, we need to save resources and energy and the in the summer, lots of sunlight and therefore UV light is signal of food abundance, when we can be more active and also put more resources into rebuilding, whatever is needed.
Of course, staying on the direct sun for 8 hours in average without protecting your skin is extreme for most people (and except of burns, it also leads to more tan and slower vitamin D absorption), I’d also rather suggest covering skin with clothes, if needed.
If you have lighter skin tones, vitamin D deficiency probably won’t be something you need to worry about in Taiwan. Lighter skin already supercharges vitamin D production, tuned for high latitude winters.
With an indoor job it can happen quite easily, as glass blocks most of the needed UV light.
Of course, whoever spends and hour or two outside on the sun without sunscreen, umbrella etc. should be fine.
Redoxon triple action is all you need. Put a tablet in a bidon.
Regarding internal vitamin D production, UVB radiation is required. This is more easily filtered by the atmosphere than UVA, so the angle of the sun in the sky is a factor. The closer the sun is to the zenith, the more UVB can get through to your skin, and the closer the sun is to the horizon, the more atmosphere is in the way to absorb the UVB.
As a very rough guide, your shadow needs to be shorter than the length of your body for you to receive enough UVB to produce Vitamin D.
And that sunlight can also have potentially much more serious effects, as I’m sure you know. I’m not always on the bike and do in fact leave my house, often without sunscreen, for other reasons.
white people superpowers 
None of the ones claimed to be longer lasting have been all that effective in my experience, not for full days in the saddle at least.
I take a small 50 ml bottle for top ups. The same kiddy stuff I have for my 3 yo. Seems to last as long as the others.
Well, great for high latitude winters, sucks in the sub-tropics when it leads to more sunburn or worse.
Same for lighter irises and better vision in low light situations. There are pro and cons for every adaptation.
Mostly cons every time I go outside and get blinded