Hydration is perhaps one of the most overlooked keys to health and fitness. When you're properly hydrated, your energy levels are up, mental clarity is boosted, and your body is primed for exercise. 

One step to ensure you're not overlooking hydration is to get a water bottle that makes you more inclined to sip frequently throughout the day. Of course, you need it to work for your hobbies—whether that's hanging off a mountainside or running ultramarathons—and, most important, keep your water just how you like it: cold. We've rounded up the best bottles for every occasion and preference. Best of all, they're BPA-free. 

That's especially important since BPA—a chemical found in loads of packaging, canned foods, and water bottles—has been linked to obesity, according to a study from the University of Iowa. BPA is absorbed through your body through any food or water that's been stored inside a container that isn't BPA-free. Once in your body, the chemical throws off your endocrine system, escalating your risk for obesity, diabetes, and cardiovascular disease, the researchers say.

Luckily, BPA's recplacements—BPF and BPS (bisphenol F and bisphenol S) have no link to obesity, researchers found. They stress that, because BPA is still present in more than half the global market share for chemicals, your best bet is to opt for products that don't contact BPA.

Take your pick through these 10. You'll always be (safely) hydrated and ready for whatever demands your training sessions—and life—throw at you.