Shimagnolo

https://www.outsideonline.com/238075...cancer-science

Fascinating counterpoint to all we've been taught.

tyrion

30 minutes of sun is one thing, but what if you're outside most of the day?

FrenchFit 

Yeah, for the million of years before 1970 humans limited themselves to no more than 30 minutes a day of sunlight.

lol .

Next up, sunglasses. Those that dilate the pupils but don't block all forms of UV.

asgelle

Maybe stop and think about this in the context of evolution, complexion, and skin cancer morbidity.

OBoile

I've long thought that the guidelines on sun exposure don't make much sense. Now, keep in mind, I'm not expert, but I think the following points are generally true:

1. People often take an all-or-nothing approach to health issues. If "too much" of something is bad, the recommendation is to cut it out entirely (or almost entirely). But, often the human body doesn't work that way, to little can be just as bad as too much. Too much salt is bad for you, so is too little. Ditto for water, saturated fat, total food intake, exercise etc.
2. Often, the recommendations are made by people who deal strictly with the "too much" side of things. They also tend to put more importance on their particular field than others. For instance, people here value aerobic ability more, and muscular strength less, than people on a strength training forum would. Dermatologists, deal with skin cancer regularly, so it's natural for them to have some tunnel vision on the matter.
3. Vitamin D is believed to have a lot of health benefits (although the article brings this into question a somewhat, as it may be another sun-related mechanism that improves health). These benefits include a reduction in the risk of many types of cancer.
4. Vitamin D supplements don't seem to be absorbed very well by the body. The best way to get it is through sunlight.
5. People in northern climates evolved to have lighter skin. There's likely a reason for this. It makes sense that this would be linked to reduced sun exposure.
6. People would freak out at the idea that a tan is the result of damage caused, by the sun, at the cellular level. But, exercise causes damage at the cellular level and no one thinks it's bad. That's not to say these are necessarily equivalent, but it does mean that damage causing an adaptive response isn't necessarily the end of the world.

The article, for those who didn't read it, goes into a bunch of other points that I hadn't considered before and won't repeat here, but it's very good IMO.

Anyway, I don't think there's some sort of massive conspiracy funded by the makers of sunscreen or anything, but I also don't stress too much about sun exposure. I figure, as long as I'm not getting a burn, I'm probably good. I'll put sunscreen on before a long ride (but it probably won't be SPF 30), but I'm not one of those types that always wears it, or puts it on under my clothes or anything like that.

kingston 

I got this sunburn on a 600k in July using some store-brand SPF 50 sport chemical sunscreen. It still hasn't gone away completely over 6 months later. I switched to Thinksport 50 mineral sunscreen after that and reapply at every control. My strong preference is to avoid sunburns if I can. As the article concludes "it's your call".

Altimis

I am pretty sure they means completely naked sun exposure or beach naked. For 30mins in whole body will be good for a day.

If you wear cloths, the sun ray will hit only your head, forearm and shin. That may need more than an hour to get enough Vitamin D for a day.

Time of day also play crucial role, early morning will have weakest sun ray, midday will be the best and then evening.

Cyclist0108

That's a bad burn.

Get a pair of these:

https://www.pearlizumi.com/US/en/Sho...ees/p/14371703

Shimagnolo

I have a pair of those (but De Soto brand) in black.
I chose black because I knew I would promptly get chainring gunk on white ones.
I always wear them with shorts, and I've never been burned through them.
It is surprising how effective they are, considering they are practically sheer.

Cyclist0108

I've decided that physical blocks are better than chemical blocks, when it is possible to use them.

I almost always wear long-sleeved jerseys and try to avoid peak UV (11am-2pm) in the summer.

There is some evidence that at least some of these sun blocks might actually be photo-activators that can increase the chances of developing melanoma, even if they offer some protection from basal and squamous cell skin cancers. The zinc oxide-based ones are probably the safest of the chemical blocks. I try to stay away from the oestrogen-mimics and nanoparticle-based options.

Carbonfiberboy 

I always wear arm covers, white sun sleeves in summer. Even on extremely hot pass climbs, I've found them no worse than bare arms. Sunscreen's been my choice for legs and face. I've yet to see a rider with a sun mask. I don't think so. Why do I wear sun sleeves? Because I could see that the skin on my forearms was going to the devil even with the application of sunscreen. I use Aloe Gator SPF 40, only one application at the start of even a long ride. Sweat doesn't seem to take it off. 10-14 hours in the sun is a long time. Following the SPF definition, 20' X 40 is 800 minutes or ~13 hours. Seems about right. My legs get a little tan over the summer, but not greatly tanned. I wear black shorts, but otherwise my kit is light colored, including a white skull cap under my helmet to cover my sparse head hair. Prevents the striped skunk appearance. On one hot pass climb I saw a rider ahead of me, dressed all in black, wrists to shoes, riding upright with his arms held out to catch the tiny breeze. That was right before he was sagged off the course. My guess is that "cold black" isn't.

kingston 

I got a pair of the castelli sun legs. Used them once and found the silicone gripper to be uncomfortable. It may have been the burn that was making them uncomfortable, so I'll try them again next season. I did a little research and went with a good mineral sunscreen instead. My mistake was buying cheap sunscreen not re-applying frequently enough. I have been wearing long-sleeved rash-guards under my jersey for years.

Seattle Forrest

Agree 100%.

pdlamb

The interesting point in the article for me was the claim that melanoma is not an automatic death sentence. The dermatologists I've talked to always claimed it was very serious, often metasticized (sp?) before it was be treated, and was therefore deadly. I'd like to see some sources for the author's claim.

Chinghis

That's a fantastic article, thanks. I love the margarine reference, as a person who grew up in one of those states that banned it.