More Refreshing Than: Rock Climbing
Sailing requires extreme concentration and builds upper-body strength as you pull and throw ropes, push the boom and climb up the mast of bigger boats. Standing on the deck and controlling the sail will also give you a killer core workout. You'll be in the hot sun (just like rock climbing), but you'll also be feeling a cool sea breeze. This can be a dangerous sport to jump into without any experience, so check with your local community center or yacht club to see if they offer lessons.
DIY and Stay Cool: Sunfish sailboats are small, broad, fiberglass boats with a simple rigging system that makes them less complicated for novices. Bonus for the supersweaty: They're still prone to tipping, so it's likely you'll be taking an impromptu dip (wear your swimsuit). Bonus for the supercautious: They're self-righting and virtually unsinkable.
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