Prevention.
So what are the best ways of thinking ahead to prevent sunburns?
#1. Understanding how Sunscreen Works
You might think SPF 30 is twice as good as SPF 15 and blocks out twice as much of the sun's UV radiation, but you would sadly be wrong. That isn't actually how it works. It seems logical that 30 should be twice as good as 15, and likewise 45 and 60 should be three and four times as good, but that isn't how it works.
According to scientists:
SPF 15 blocks approx. 94% of UV radiation.
SPF 30 blocks 97% and SPF 45 blocks 98%, and SPF 60 blocks 99%.
So with numbers in the low to high 90s, this sounds pretty good, right? Sadly this assumes that the person applies the sunscreen liberally on their skin. There are other factors too:
- Some places on the skin might get less sunscreen.
- Sweat from exercising or extreme heat can cause the sunscreen to become diluted and less effective.
- How often you reapply sunscreen.
- The brand of sunscreen also varies in efficacy*.
* Some brands of sunscreen contain chemicals that the U.S. Food and Drug Administration have a watch-list for being potential carcinogens like titanium dioxide and octyl methoxycinnamate (OMC).
Because people often forget to reapply sunscreen, I recommend setting an alarm clock on your phone to remind you to reapply. Most companies recommend applying every 2 hours, but if you are worried you might forget then maybe aim for every 100 minutes or so.
If you are exercising and sweating a lot, you might even reapply once per hour.
If you are especially worried about getting a sunburn then you should always apply sunscreen liberally, as if you are a vampire who will die if you don't.
Do not use sun tanning oil. The SPF in that is so low it is basically non-existent.
#2. Limit your Exposure Time
The first half hour or hour, most people will be pretty safe from UV radiation depending on how vulnerable a person is. Some people are more pale and get sunburned easily, so they need to limit their exposure more.
So if you are exercising outdoors you might want to set a time limit for how long you are exercising, like 45 or 60 minutes, and then go someplace in the shade to cool off. Combined with sunscreen this is a very safe strategy.
You could even take a break for awhile, and later reapply sunscreen and resume exercising for another 45 to 60 minutes.
#3. Deliberately get a Tan
So your skin is actually pretty good at blocking out UV rays, but to do so it needs to be tanned. The darker shade of skin blocks more harmful rays from the sun and protects you. The more you tan, the more protected your skin becomes from UV rays.
The trick here is to get the tan, without getting the sunburns... and that means sunscreen and possibly limiting your exposure time. So you would need to be setting specific times to "go to the beach or park and get a tan" or whatever it is you are doing, and set a specific amount of time you will be spending at the beach, park, etc tanning. That or reapply sunscreen using an alarm clock on your phone to remind you.
#4. Tightly Woven / Loose Fit Clothing
Fabric that is too thin and not tightly woven can still let through lots of UV radiation, causing you to get a sunburn right through your shirt.
You should also bring something extra to wear in case your sunscreen wears off or runs out.
Try to pick clothing that is also comfortable to exercise in.
#5. Hat and Scarf
A good hat or scarf can protect you face and/or neck from sunburns. eg. A bandanna tied around the neck like a scarf also works well to prevent sunburns on the back and sides of the neck.
A big floppy hat is not ideal for exercising in, but a baseball cap and a bandanna would work nicely.
#6. Avoid 12 PM to 4 PM
The worst times of the day to be outside in the sun is approx. from 12 PM to 4 PM. So if you want to exercise and avoid those times, try to exercise in the morning or late afternoon / evening.
#7. Plan your Route / Day
Lets say you are going jogging. Plan a route that takes you under lots of shade trees so you are limiting your exposure to sunlight.
Or if you are doing an activity where you know you will be in direct sunlight, plan out specific times during the day to take breaks, drink water, eat snacks, and reapply sunscreen. (Recommend eating first before applying sunscreen. Nobody likes tasting sunscreen in their food.)
#8. Vitamin Supplements = Minor Benefit
There are some benefits to taking a vitamin D3 supplement, in that sunburns won't be as severe, but it doesn't prevent sunburns. So you can take it if you want to, but bear in mind it doesn't prevent the sunburn itself. Anyone who claims it prevents sunburns is basically perpetuating a myth.
Some people have deficiencies in zinc and magnesium (likely due to a shortage in their diet or a genetic disorder), and as a result have more photosensitive skin. Taking vitamin supplements or eating foods that are higher in zinc and magnesium are helpful for people with those conditions, but will not benefit the average person.
Health claims by 3rd party websites and the supplement industry should be treated as biased and suspect. In researching this post I determined a lot of websites were advertising vitamin D3 and other supplements, and that they were exaggerating the benefits of taking the supplements.
Happy Exercising!