Sunscreen vs Clothing and body temperature
 

Found a couple studies, but IMO nothing definitive since they mostly are conducted on indoor trainer (no wind) or are measuring sweat output only, and not taking into account evaporative cooling effect (eg. Does sweat evaporate just as well when mixed with sunscreen, vs. technical fabric ability to promote evaporative cooling?)

Anyone have their own thoughts/insights/experiences to share whether for example a lightweight Longsleeve jersey or base with UPF 30 protection might compare to bared skin with SPF 50 lotion applied, in terms of allowing the body to regulate its temperature in hot/humid conditions?

I wear long sleeve SPF shirts and then shorts with SPF sleeves over my knees. Sometimes I even wear 3/4 pants, specifically the ones adidas makes for soccer. I feel like loose flowing clothes keep me cooler than sunscreen. I ride during the business end of summer in Texas.

I also recently discovered Prana Hybridizer joggers for MTB riding. I have to wear full coverage because of poison ivy. Anyway, I discovered they are great for air flow and might even try them on road rides. They provide SPF protection but have tiny perforations.

I’m kind of a nut about sun protection because family cancer histories and my own skin cancer scares.

You almost have to try both and see which one works best for you.

Sunsleeves do OK for me up to mid-80s at home, perhaps 90F or so in low humidity (<25%). I've never had problems with sweat evaporating over sunscreen, except of course when it's so humid nothing evaporates, period. (Bullfrog get is my favorite; works well and can be applied over moderate sweat.) So if I'm out west in spring or fall, I may take the sunsleeves, but I'll also take sunscreen in case it gets too hot.

And to reiterate, YMMV.

i used to sun screen. lately i have been wearing SHARK ZEN long sleeve performance shirts. the shirt is probably healthier and it cools you better. rock climbing pants will also give you a lot of biking comfort. i ride fix in the city and SS on gravel. the daily temps down here index at 100+

Not to call anyone out but what is SPF clothing? Isn't all cloth sunblocking?

I do prefer light weight, long sleeve, hi vis shirts but put sunscreen on the back of my neck

Not all cloth is dense enough to prevent UVA and UVB from reaching the skin, and have various capabilities at long-term protection. Keep in mind that the UV spectrum is outside the human eye's perception without technological aids. Just because clothing is opaque in visible light does not mean it is opaque to UV light. I'd venture that almost all modern opaque shorts are dense enough to block the sun, but with jerseys YMMV. Knits are problematic in that they stretch, possibly allowing UV transmission. Loose weaves have the same problem. A wet cotton t-shirt (a knit) will provide a UPF of 3, or for every 3 units of radiation, one is reaching your skin, basically a 66% reduction in harmful UV over no protection whatsoever. UPF of 50 is a 98% reduction.

More reading if you're interested.

Sun sleeves > sunblock, 100%. Sunblock is only effective until it is washed/sweated away, and during summer cycling I will sweat from start to finish, so any sunblock might be gone within half an hour. Also really fun to get into the eyes. Some sunblocks are also pretty aggressive against lycra and other synthetic fabrics. Sunblock on my nose and neck only.

Not at all. Not all jerseys are created equal, as I have some cheapo Canari jerseys that leave me with a bib-tan if I wear them too many days in a row. Lighter weight, looser weave fabrics (which is a lot of jerseys) let in more UV, unless the fabric is specially treated. UV pretty much goes straight through white cotton as well.

Sy Reene Don't forget that there are two types of sunblock, reflective, and transformative. The mineral-based (zinc oxide, titanium dioxide) sunscreens act to reflect UV radiation, while the chemical sunscreens (octinoxate, avobenzone, etc.) convert UV radiation to heat. I use both, but apparently the chemical sunscreens are better for sweating heavily (they absorb into the skin, under the sweat).

I was going to suggest the reflective to feel cooler, but it rarely stays put. I just ride early in the morning while the sun is still low.

Thanks for the info. Link states dark and bright colors offer better protection

Fortunately I don't wear standard bike jerseys and instead wear things like Dickie's long sleeve cooling T shirts. Just checked their web site and they claim UPF 50. Looks like most of the inexpensive synthetic T's I buy at Walmart are the same way.

Those yoga pants surely are not all that UV protective.
I bet there will be a study to reveal the hazards of yoga like pants related to sun exposure.

The old rule of thumb with clothing was that if you could see through it you could get sunburn through it. Remember that a sunburn is actually a radiation burn.

I've also read that SPF 30 is the best protection and that stuff above that doesn't really do much more.

Also, an SPF rating is for each INDIVIDUAL. It simply means the factor by which you can increase YOUR sun exposure without burning.

Cheers

You talking about the Prana pants?
You might be right. For some reason I had it in my head they were SPF rated but it doesn’t look like it. Dang.

I hate sunscreen, so I'm in the cover-up camp. Long sleeve top, full-finger gloves. Sweat evaporation out of sleeves can really do wonders - have even been cold at moments as I start up after a refill stop.

That said grabbed a short sleeve the other day for an evening ride in the three hours preceding sunset, that was nice, too.

And I've chosen to go with a big helmet brim during the sunny hours, though I sometimes tie it to my back earlier or later. If I were doing roadie speeds that might not work well, but for the long duration of my slower rides it's been key.

I used to wear long sleeve lightweight wicking fabric t-shirts in summer -- inexpensive stuff from Champion, or Under Armor and others if I could snag a bargain at Marshall's or Ross. Didn't feel any hotter than going bare-armed.

And I have a Pearl Izumi snug fitting long sleeve jersey of ultra-thin material that's supposedly SPF 30. It's comfortable in all weather.

But my docs have been fretting at me over premature bone density loss, low vitamin D, calcium, etc. Full body scans (MRI or CT, I don't remember which) revealed I had a bunch of healed fractures that I wasn't aware of because I rarely visit a doctor or the ER for falls and impacts that I thought were just bumps and bruises, or rib injuries that can't be treated anyway if there's no compound fracture or perforation of organs. And supplements weren't helping. So after a year and reading a bunch of PubMed studies (not all were credible or peer reviewed, but some were useful), I decided to try a different approach.

Conventional wisdom said I needed sun to kick start my body into making vitamin D and hopefully improving my bone density.

Other studies indicated sunscreen might not even prevent skin cancer, and that there may not be any evidence of a connection between sun exposure and skin cancer. This was all new to me and I'm still skeptical.

But I was willing to give it a try.

I ride in midday summer heat with regular short sleeve jerseys (and I plan to get at least one sleeveless) and don't wear sunscreen. Nada. I just let the sun do its thing. My rides range from an hour to 4-5 hours.

The weirdest part of this experiment is I don't sunburn anymore. I used to burn like kindling at the slightest hint of sunlight. If I wore sandals the first day in summer, within 15-30 minutes I had beet-red stripes wherever there were gaps in the sandals.

But some of the studies I read (again, not all were peer reviewed and might be considered, at best, educated guesswork by qualified scientists) indicated that it's possible to affect our sun sensitivity through diet and body fat. Specifically, by lowering our sugar and alcohol intake and reducing body fat, we may be less vulnerable to sunburn.

I figured it was worth a try so I did that in springtime last year, 2019, fully expecting to go home cherry red and needing that lidocaine sunburn spray I already had in the bathroom.

Nope, I just tanned. No burn. I repeated that several more times. Same results. I just tanned. No sunscreen.

Looking back, it seemed like my worst sunburns occurred after I'd put on weight, ate a lot of sugary stuff, drank beer, etc. By the late 1990s I got up to 205 lbs for a few years when I seemed to burn worst. My optimal weight is around 150 so that's significantly overweight for me.

Resuming bike riding in 2015 got my weight down to 175, then 160 and stayed there through 2017. I ate and drank whatever I wanted, as much as I wanted.

Then thyroid cancer in 2018 made it really difficult to swallow so for much of that year I was on a liquid diet and soft foods. And the thyroid failure seemed to kill my ability to metabolize alcohol. I loved good beer and rarely got more than a mild buzz no matter how much I drank. But after the thyroid thing a single beer made me feel sick and hungover within an hour or two. So I switched to a mostly vegetarian, high protein diet that year. My weight dropped to 150. I've since switched to a more meat-heavy diet now that I can swallow again. But I'm still avoiding alcohol, sugar and most carbs, although I'll eat more carbs for heavy workout days and bike rides. I'm not a keto purist.

This year I'm still skipping the sun screen and UV resistant sleeves. I ride mostly during peak sun hours, although occasionally if it's too hot and humid I'll start later, after 6 pm. But I still don't sunburn. I'm not even as dark as I'd expected. My legs barely have any tan, other than my knees. Same with my face. There's no discernible helmet and sunglasses-tan pattern. There's a slight irregularity in the tan on the back of my neck, because I have a ponytail.

It's mostly my arms that get dark. I can't say it's a good look but that's just the way it goes with aging skin. At age 62 my skin looks my age, with that weird mottled old man tan. Oh, well, I'm not doing it for cosmetics, just trying to improve my bone health.

I'm looking forward to my next bone density scan and lab tests. Just curious to see whether this experiment makes any difference.

Anyway, don't take this as a recommendation. Just one odd anecdote. I guess I'll know in 10-20 years whether it was a good idea if I develop skin cancer.

I have always had this ability to tan dark extremely easily and never burn so I usually don't wear sunscreen or forget to and I never get burned I just tan. I never have to worry about poison IVY either, it's never effected me. I would play in the woods all the time as a kid and never break out and my cousins would all be itching like crazy :) I just took a whiz in the woods two days ago off the bike path in poison IVY, never broke out :)

I usually wear a tank top with boxer underwear and shorts or blue jeans or khakis. For footing I will wear sandals or casual shoes or a pair of tennis shoes. Sometimes a helmet, other times just some kind of hat.

I'm not a fan of sunscreen either. I can only imagine the long term affects the chemicals will have absorbed into my system.
I guess I'm one of the lucky ones....once I get a base I rarely burn from "long sun exposure". That said, I try to cover up with clothing and will dab some sunscreen on the back of my neck, ear tips and nose.
If I'm riding in humid weather I prefer cotton based shirts vs synthetics (feels clammy when damp)

Just so everyone knows: a tan is another word for a minor sunburn.

The tan is just the upper layer of your skin, the epidermis, producing more pigments to protect the dermis below, and is reasonably safe. Exposure is even necessary to promote vitamin D production. A burn is when there is prolonged exposure to strong UV that penetrates down to the dermis. This is more harmful.

I am also quite weary of sun exposure, and I prefer to cover up rather than chemical--gloves, longer bibs/shorts, longer socks even. I'll put sunscreen on my arms and then armsleeves because that's the one body part that is constantly exposed to direct and strong sunlight. Sunscreen on my face and neck, and extra on the nose and ears.

I love summer riding, but that's the one hassle that I do not like.

Howdy, I’m really only pushing this point because it's a health issue. Lord knows there are enough debates on this forum :). But, no, there is no such thing as safe tanning, unless it comes out of a bottle. I just did a quick search and any legitimate source (university research, government research) states this unequivocally. Any dermatologist will say the same.

Again, not trying to start any argument, just want people to protect their skin! :)

If someone wants to tan, great, just know there are risks. There are also other ways to get vitamin D. Sorry, I’m kind of a nerd about this and probably not everyone needs to worry about it as much as I do.

I spent a couple hours yesterday around noon bicycling around town. When I was done my arms were hot and I could see a clear difference in skin colour between the part that my bike jersey covered and my exposed arms. I had forgotten to put on sunscreen because it was a bit overcast when I started out.

Last night I ordered UV sleeves and coated my face and arms with a liberal amount of sunscreen for todays trip ride. Once the sleeves arrive I'll be able to wear those with all my short sleeved jerseys.

I have no knowledge of family medical history so for me I'm just going to stay safe, cover up as much as I can and wear a lot of sunscreen.

I've got that Anglo-Celtic phosphorescent white skin. I practically glow in the dark. I can get a sunburn in half an hour at noon in the summer. In my family we joke that in full sunlight our skin starts to bubble and smoke like Christopher Lee at the end of Dracula.

So, I wear sunblock. SPF30 on the arms and legs, and 50 on the neck, ears, and face. I used to slather it into my balding pate, too, but I've gone with a skull cap recently. I can ride for 3 sweaty hours or more without burning in high summer that way.

Fair enough, but one could make the same argument that nothing is 100% safe with just about anything...pesticides in foods, plastics, the water we drink, alcohol, driving, riding a bike, etc. The fact that we are not all dying of skin cancer, just as we are not all getting other types of cancer from environmental causes tells you that there's is a level of sun exposure that is reasonably safe. There are people who are more predisposed to getting skin cancer from UV exposure, and these are the ones who need to be more vigilant about covering up.

no sun screen

clothing is all based on relative humidity. low humidity = loose clothing, high humidity = tight wicking clothing.

now mix that with how fast I plan to ride, flappy clothing at 20 mph sucks... in my opinion.

UPF standards vary. There is an American and an Australian version. I think both only test new, unworn, unwashed, unstretched fabric, so the rating can be misleading for normal use. There is a newer UV standard 801 from a private group that supposedly tests the fabric after several wash cycles and (I think but not sure) some amount of stretch, but I think very few companies actually advertise this test. I might think about buying those next time though. I've always worn long sleeve shirts and pants with UPF 50 from REI, and also summer long finger gloves. It's really itchy when you sunburn your fingers. I wear sunscreen on face and neck.

What an interesting thread. Everything from happily going with no sunscreen to "there is no safe level of tanning"!

Regarding SPF levels of clothing, I've made an interesting observation. I wear a wide variety of jerseys/shirts, which surely vary in SPF ratings. Yet I never burn or even tan in the areas which are covered. This leads me to believe that SPF rating is not as important as just covering up with something.