Summer officially started on June 21, and stores across the country are starting to catch up with the outdoor enthusiasts and aisles are filling with sunscreen options. But how do you know what’s best? What should you buy?

Related: Six tips to help protect your eyes from the sun

Sunscreen may seem like a pretty simple topic, but it can get complicated depending on how you intend to use it. A lazy afternoon in the park spent lounging around does not demand the same expectations of its sunscreen as a long run during the hottest days of summer. Here are a few tips for summer training and sunscreen.

Apply, reapply and reapply

First, before you even pick up a bottle off the shelf, remember that simply applying a layer before heading out for an entire day in the sun is not enough. You should try to reapply every two hours to stay protected. Also, not all clothes will adequately block you from the sun’s rays. Some of your gear may have fibres that block UVA and UVB rays, but many won’t. Check and see if you need to apply sunscreen under some of your clothing.

Go for high SPF, but don’t be fooled

A high SPF sunscreen is essential for prolonged periods in the sun but SPF is measured in strange ways that can be deceiving, so don’t get fooled. As SPF gets higher, you gain less protection per point. It’s measured as a length of how long you can stay in the sun without burning, relative to wearing no sunscreen at all. An SPF 2 sunscreen filters about 70 per cent of UVB rays. Jump to 15 and it filters out 93 per cent. At SPF 50 a sunscreen will filter out about 98 per cent of UVB rays and anything above that is likely just a marketing gimmick.

Related: 5 Tips for Sunny Vacation Runs

Grab a broad spectrum lotion

Notice that SFU is a measure of the UVB rays a sunscreen filters, but UVA rays are also dangerous to our skin and need to be filtered, which is why it’s essential to make sure you buy broad-spectrum sunscreen. Almost all sport sunscreens will be broad spectrum and a quick glimpse across the packaging should tell you for sure.

Don’t bother with sunscreen that doesn’t protect you against UVA rays also. Your skin will thank you later.

Water resistant

Buy water- and sweat-resistant sunscreens. Some may advertise themselves as waterproof but don’t completely believe it. There isn’t a truly waterproof sunscreen. All of them will wash off after extended time in the water or if you’re sweating a lot, but a good water-resistant sunscreen should be fine – remember to reapply (especially in an Ironman or half-distance triathlon).

Pick your style

Sunscreens these days comes in many forms beyond the traditional lotion bottle. A spray bottle is always a good option, but beware it can be tricky to put on your face or if it’s windy outside. Some sunscreen sticks, which work like deodorant sticks, can be useful for quick application on your face.

Think about what and how you’re going to be using it. If you’ll have time to evenly coat yourself before heading off on a run or if it needs to be used quickly and on the fly.

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