Hydration is a key component to performing your best, no matter the form of exercise. Just as your fuel needs to stay topped up, so do your fluids. Running, however, provides some challenges when it comes to staying hydrated. You have to take water along with you as you run, and that can be a hassle to carry.
Where there’s a will, there’s a way, and plenty of companies have come up with hydration solutions for runners. Soft flasks and collapsible bottles are two of your many options. This post will delve into the best of the best in this category. Dehydration can have some nasty side effects and set you back a couple of days if you’re training, and these bottles are here to help.
The best soft flasks and collapsible water bottles could make a huge difference to your running!
Our number one choice is the Katadyn BeFree Water Filtration System 0.6L. It has a 0.1 micron water filter that removes up to 99% of bacteria from your water, and requires no fancy cleaning.
Keep reading to find our top choices for every runner.
Top 3 Best and Favorites
Katadyn BeFree Water Filtration System 0.6L
Salomon SOFT FLASK 500ml/17oz SPEED 42
Hydrapak Stash 1 L
Best Collapsible Bottle With Filter
1. Katadyn BeFree Water Filtration System 0.6L
Have you ever run out of water halfway through a run and been so far out that you couldn’t just stop and fill up somewhere? The Katadyn BeFree is the answer to these sorts of issues.
With a handy 0.1 micron filter, you can stop at any water source and take a drink comfortably and confidently. The filter removes dirt, debris, and up to 99% of bacteria too, keeping you safe and hydrated in any environment.
It’s the perfect solution for cross country or trail runners who spend time out in the countryside. Hikers would find it extremely useful too, but even runners who spend most of their time on urban roads would benefit from the health-promoting product.
Don’t think the fancy filters will make it hard to clean, though. A simple rinse will suffice, so it’s useful and convenient!
Just be careful not to overfill it, as the extra pressure could cause the bag to burst.
- 0.1 micron water filter
- Easy to clean
- Chemical-free filtration
- Free Flow nozzle
- The bag could rupture if overfilled
Most Versatile for Race Packs and Handheld
2. Salomon SOFT FLASK 500ml/17oz SPEED 42
Salomon makes rugged stuff for the intrepid explorer, and this little flask is no different!
It’s skinny and long, which makes it fairly easy to slip into any backpack or hold comfortably, although some runners may find this unusual shape to be strange or not fit well in their hands. Technically, these are designed to be tucked into the front pockets of a running vest.
This soft flask can hold 17 ounces of water at full capacity, and the handy measuring scale on the side makes it easy to keep track of how much water you have left.
It gets a thumbs-up for its wide mouth, which makes filling it up super easy. The “shrinks as you drink” feature makes it easy to simply stick it in a pocket when it’s empty.
You can purchase a filter separately if you want that feature.
- 17-ounce capacity
- Wide cap for easy filling
- Handy measuring scale
- Shrinks as you drink
- It’s longer and thinner than most, and some may find it uncomfortable to hold
Ultralight with Easy-to-Hold Design
3. Platypus SoftBottle .5L | 1.0L
Weighing in at less than 1 ounce when empty, this lightweight little flask is one of the easiest and most convenient around.
You can choose between 0.5 liter (17 ounces) and 1 liter (33 ounces) sizes. When it’s filled, the SoftBottle bottle can stand upright and fits nicely into cup holders or vests.
The “indented waist” design makes it very easy to hold and drink from comfortably. Once empty, you can simply roll it up and stick it in whatever small space you have available.
For added safety, the flask is BPA-free, BPS-free, and phthalate-free. Some customers report a plasticky taste when drinking from it, but they’re few and far between.
The biggest complaint is that the constant rolling up of empty flasks can lead to the plastic cracking. If you treat it right, though, and don’t fold and unfold it unnecessarily, it should be quite durable.
- Unique, easy-to-hold shape
- Flattens and rolls up when empty
- BPA-, BPS-, and phthalate-free
- Stands upright when filled
- Due to folding/rolling, these bottles aren’t as durable as some others
Best Lifetime Warranty
4. Hydrapak Stash 1 L
In a world of sub-par products, one that offers a lifetime warranty is super to see! Hydrapak is so confident in the quality of its product, that they’ll repair or replace it for free, whatever your issue.
It comes in 1 liter (33 ounces) or 750ml (25 ounces) sizes. Whichever you choose, it looks and behaves like a hard bottle when filled, and twists and flattens to ¼ of the size when empty.
It’s also about half the weight of a normal hard bottle, which means a freer and easier run, whether you’re holding it in your hand or have it in a pocket or vest.
The bottle is constructed from abrasion-resistant TPU that’s free from BPAs and PVC. It’s safe for you, and able to withstand a bit of a beating, so it’s the perfect drinking companion on the road or trail.
If something does happen to it, the company is more than happy for you to get in touch and use that lifetime warranty.
- Lifetime warranty
- Available in two sizes
- Abrasion-resistant TPU
- 50% lighter than most
- The lid isn’t attached to the bottle, so it can be easy to lose and requires 2 hands to open and drink
Best Hand-Held With Straps
5. Nathan Handheld ExoDraw 2.0 Insulated
If you’re more comfortable holding your bottle in your hand while you run, then this one could be the best choice for you.
The flask itself can be 18 ounces or 4 ounces, is toxin-free, and has a convenient bite valve for easy on-the-go use. Its ExoSpine design keeps the flask rigid and supported.
The thing that makes hand-carrying easy, though, is the bottle cover. It not only keeps your flask insulated, but it features a couple of handy stash pockets and a soft, adjustable hand strap so you don’t have to grip it too hard while running.
If you happen to have small hands, the strap may not adjust quite tight enough to allow you to relax your grip. Regardless, if you’re used to carrying your bottle in your hand, that won’t be enough to take away from this flask’s value.
- 18-ounce or 14-ounce bottle
- Insulating cover in various colors
- Wide, soft, adjustable hand strap
- Stash pockets
- Runners with small hands may find that they can’t adjust the strap tight enough
Top Eco-Friendly Bottle
6. Nomader Collapsible Water Bottle
Eco-friendly running gear is on the rise, and if you prefer brands and products that are environmentally-friendly, you’ll be interested in this water bottle.
Not only is it planet-friendly, it’s quite stylish and comes in a variety of striking colors.
The body is made from silicone, which makes it immune to most things, including dropping. It’s thick enough to be hard to tear, as well.
Nomader has patented their leak-proof cap, so you shouldn’t be losing water on the road even if your bottle is a little lopsided.
We like that you can carry both hot and cold drinks in it, and as an added convenience, it’s dishwasher-friendly!
- 100% food-grade materials
- Wrist loop for easy carrying
- Patented leak proof cap
- The silicone body can be difficult to roll up when it’s new
Smallest Design with Strap
7. Osprey Packs Duro Handheld With Soft Flask
Runners who tend to stick to shorter distances will do well with this little 8.4-ounce hand-held bottle.
The flask itself is soft and foldable, but quite sturdy when filled. But the important part of this product is the hand strap. It’s designed in such a way that the bottle rests on the palm of your hand, making it easy to simply lift your hand and take a drink at any time.
Tighten it accordingly using the adjustable straps, and you won’t even need to close your hand around the bottle.
If you need your hands free, you can strap it on so the bottle rests on the back of your hand so you have full grip for other things.
Some of the extra features we really like include a tucked-away safety whistle, a mesh pocket, an open pocket, and the ability to use it on either hand just as effectively.
- Can be placed on front or back of hand
- 2 small pockets
- “No-grip” design
- Includes safety whistle
- May not be big enough for some runners, or for long runs
Best Body-Shaping Design
8. Ultimate Direction Body Bottle II 500
It can be uncomfortable having a hard bottle in a pocket or up against your body as you’re moving. Even some soft flasks can feel like they’re poking at you.
This soft flask is designed to move with you as you move, staying comfortable no matter what. It’s designed from all-soft materials, and features an angled silicone push/pull bite valve for easy reach and use.
The mouth opening is also fairly large, allowing you to add ice for those sweltering days, or powders for your recovery drinks.
- Soft design for comfort
- Taste-free and BPA-free
- Angled cap for easier use
- Large-mouth opening for adding ice or powders
- May not be as durable as some others due to the indented design
Top Hands-Free Design
9. Hydrosleeve Hands-Free Armband Hydration System
Sometimes going hands-free just gives that extra bit of freedom. This is our top choice for hands-free water bottles, although the 7.5 ounce capacity may be too little if you’re going to be on a long run.
This nifty little arm pouch has been ergonomically designed to fit the upper arm. You can choose from a small, medium, or large, although this is just for arm size – the size of the water bladder remains the same.
Their Therma Cool insulation keeps your water cool while you’re running, and they also use “slosh-free” compression tech to prevent the remaining water from annoying you.
- Various sizes available
- Therma-Cool insulating tech
- Angled valves for easy use
- Versatile enough for all types of exercise
- 7.5 ounces may be too little for long-distance runners
- Some may find it difficult to drink comfortably due to the angle
Hydration is something you can’t afford to neglect while running! You may not feel dehydrated straight away, but it can have a significant impact on your performance.
If you’re wondering about soft flasks and how they can benefit you, we answer some common questions below:
How Can I Carry My Water On My Runs?
Carrying water with you when you run is important. There are a few ways you can carry it with you while on the move:
This is probably the most common, and runners have been doing it since long before the days of hydration packs and fancy tech!
It can become uncomfortable holding a bottle in your hand, though. Old-school plastic bottles can begin to feel like you’re carrying a brick around, and even though you may not realize it at the time, it can weigh you down and throw you slightly off balance.
Hydration Pack in Backpack
Hydration packs are super useful, and much less chunky than carrying a bottle. Not only do they distribute weight more evenly when they’re strapped to your back, but they leave your hands free to run with normal form.
A race vest has space to store your bottles of water so you can have a hands-free experience. Usually, they’ll have space for two bottles, so you can take a decent amount of water with you.
Yes, bottle holsters are a thing! You can get them for the thighs or upper arms. They work with either bottles or hydration packs.
What Are The Benefits of Soft Flasks?
If you’ve always used old-school plastic bottles, you may be wondering why making the switch to a soft flask would be worth it. Here are some of the biggest benefits of using a soft flask:
Even though soft flasks are still made from plastic materials, they’re easier and safer to reuse than disposable plastic water bottles.
The best thing about soft flasks is how little space they take up. Obviously, when they’re full, they still take up a bit of space. But the more you drink, the smaller they become!
When they’re empty, they can be collapsed down to a small enough size to slip into a pocket, so you don’t have to carry an empty bottle around with you or find somewhere to throw a disposable bottle away.
Generally, soft flasks are more comfortable to hold and easier to wrap your fingers around! They become easier to grasp the more you drink, too.
If you’re using a race vest or hydration pack, a soft flask also fits easier into a pack.
Soft flasks are made with lightweight materials and won’t weigh you down nearly as much as a heavier plastic bottle would. Especially when they’re empty!
Easy to Use
Soft flasks are simple to use and don’t need you to fight with them to get them open. Most of them use bite valves that are soft and safe, and give you a quick and easy flow of water when you need it.
Why Should I Take Collapsible Water Bottles On My Run?
Once you’ve discovered the joy of running with a collapsible water bottle, you’ll never want to go back to bigger bottles!
The more you drink out of a collapsible bottle, the smaller it gets. This is super for saving space and weight. When you’re finished, simply slip it into a pocket or waist belt so you don’t have to carry an empty bottle around.
They’re also extremely lightweight when they’re empty, so you won’t have them weighing you down at all.