The 5 When to Drink Electrolytes, According to Experts for Runners, Hikers, and Travelers

I am not made for high temperatures and sunny days. (My ADHD says “you need to run anyway.”) As a result, I'm always concerned about keeping cool on my runs, which means keeping a water bottle at the ready at all times. Hydration is critical for hot days, but you always need water. I’ve even been known to double up, keep one in hand and stashing a backup in my running belt.

Whether you're filling up with Gatorade or water, some water bottles are especially well-suited to running. They're easy to hold or hip-mounted for easy access. Having a great one can make all the difference. Just ask anyone who has sucked down water from a sketchy water fountain like they’re in a desert.

For this list, you'll notice that there's a lot of choices from Nathan. This is for a few reasons: first, Nathan's bottles really are just that good and it has the most options. Second, when it comes to testing product, they're the most well-known and popular, and therefore the easiest to get a hold of for everyone. They have reliable stock, good customer service, and they're available in multiple places.

For more great ways to stay hydrated on the go, check out our picks for the best hydration packs, and hydration vests.

• Best Overall: The insulated sleeve can be tricky to remove or reattach
• Best Budget: Can you freeze a water bottle
• Best for Women: Nathan ExoDraw 2.0 Handheld Water Bottle
• Best Grip: Nathan ExoDraw 2.0 Handheld Water Bottle
• Best with Storage: Handle is easy to adjust for even small hands

Weight, Distribution, and Attachment Style: The Balancing Act

For water bottles that you specifically want to carry with you on a run, the details matter. The size, weight and even how that weight is distributed can be the difference between a comfy, hydrated run, and one where your arm feels like it’s going to fall off.

Even if carrying a bottle in your hand doesn’t significantly impact your running economy, it can still feel awkward at first—especially if the bottle is heavy or the weight isn’t well balanced. Look for bottles with ergonomic designs and adjustable straps that let you relax your grip and keep the bottle snug, so you’re not constantly doing a finger workout or worrying about dropping it.

Attachment style matters, too: Soft flasks with hand straps or sleeves let you run hands-free, while rigid bottles might require a tighter grip. Ultimately, the right combo of weight, distribution, and attachment style will keep your arm swing natural and your focus on what matters.

Capacity: How Much Is Enough?

Handheld bottles typically range from about 10 to 22 ounces—enough for most short or medium runs, but maybe not for your next ultra. Bigger bottles mean more water, but also more weight and bulk, so consider how far you’re going and how much you actually drink during your run. If you’re hitting 15 to 26.2 miles, you may need water than you can carry in a simple bottle or belt. For longer runs, hydration vests distribute weight better and are simply more comfortable to carry. (Just powder up underneath where the vest hits—trust us.)

Some bottles shrink as you sip, making them easier to carry as you go. If you’re a minimalist, a smaller bottle will keep things light and easy; if you’re planning on a longer, hot adventure, you might want to max out capacity and accept a little extra heft. Either way, choose a bottle that fits your hand and your hydration style, so you can focus on the miles ahead and not on how swole the arm carrying the water is about to be.

At Runner’s World, we’re runners just like you. We’re dedicated to every stride and every finish line. Since 1966, we’ve been a trusted resource for the community. For this guide, we carefully evaluated each running water bottle, considering their specs and real user reviews, as well as our own testing. Our decades of experience mean you can rely on our honest recommendations to help you run smarter, safer, and more hydrated.