Running Tips
How to Do a Tempo Run
Four Reasons You Should Use a Soft Flask for Your Energy Gel
Fueling up doesn’t have to be hard with a soft flask!
By Running Warehouse Staff
Last Updated October 9, 2025
• 4 min read
They say there are two kinds of people: those who squeeze toothpaste from the middle and those who roll it neatly from the bottom. If you’re the rolling type, you probably hate wasting even a little paste stuck at the end. The same logic applies to fueling on the run; why waste gel or deal with messy wrappers when a soft flask lets you get every drop?
From reducing waste to increased versatility, a soft flask is a small upgrade that makes a big difference in convenience. Let’s dive into the top four reasons every runner should consider one.
What is a Soft Flask?
Energy gels are one of the simplest ways to refuel during a run, but carrying individual gel packets can sometimes be messy and inefficient. A soft flask is a lightweight, collapsible container designed to hold energy gel (or even liquid fuel), giving you an easy, reusable way to carry multiple servings without stuffing your pockets full of packets and access it easily while you run.
Top Four Reasons to use a Soft Flask
Reduce Waste
Even when you're being extra careful, it's easy to lose bits and pieces of gel wrappers while you run. Stashing empty gel wrappers in your pocket can also turn into a sticky mess. Using a soft flask helps cut down on single-use packaging and prevents stray gel wrappers from ending up on the trail or road. Additionally, buying gel in bulk instead of individual packets reduces waste and supports a cleaner running environment.
Convenient for Multiple Gels
If you typically carry more than one gel during your run, a soft flask helps keep things simple. Instead of juggling several packets, you can fill a single flask with multiple servings, making it easier to dispense and fuel on the go without slowing down or fumbling with wrappers.
More Versatility for Different Nutrition
A soft flask isn’t limited to just energy gels. You can fill it with honey, syrup-based fuels, or other liquid nutrition that match your preferences or dietary needs. This flexibility makes it a great choice for runners who like to mix up their fueling strategy.
Lightweight and Easy to Store
Soft gel flasks are designed to be compact and easy to carry. Once you consume your fuel, the flask is able to collapse, taking up minimal space and staying lightweight throughout your run. It’s an efficient, low-bulk way to carry your nutrition without weighing yourself down or taking up extra space.
Using a Soft Flask for Hydration
Not only are soft flasks a convenient way to carry nutrition, but they’re also excellent for carrying hydration. Whether you prefer to sip steadily throughout your run or take quick drinks during longer efforts, soft flasks provide flexible, on-the-go hydration without the bulk of a traditional water bottle.
Many runners keep one flask filled with water and another one with an electrolyte drink to balance hydration and fuel needs. Plus, the wide-mouth openings featured on most models make refilling easy at aid stations or water fountains during races and training runs. Their collapsible design allows the flask to shrink as you drink, reducing sloshing and freeing up space in your vest or belt, helping you stay light as you move.
Frequently Asked Questions
How much gel can a soft flask hold?
Small soft gel flasks usually hold around 4–6 ounces, enough for roughly 4–5 servings of gel. If you need more fuel for longer runs, larger models can hold between 16–21 ounces, so you can bring just the right amount for your workout.
Can I mix different gels in one flask?
Yes! You can mix flavors or brands, but make sure they have similar consistency, so the gel flows smoothly. Always test your combination during training before race day.
How do I clean a soft flask?
To clean a soft flask, rinse the flask thoroughly with warm water after each use. For a deeper clean, use mild soap or a small bottle brush. Let it air dry completely to prevent mold or residue.
Can I use a soft flask for other fuel?
Absolutely! Many runners use them for honey, maple syrup, or sports drinks. Just check that the consistency of any fuel you use is smooth enough to squeeze easily.
Are soft flasks allowed in races?
Most races allow soft flasks but always check your race’s nutrition rules. Soft flasks are often used in long-distance and ultramarathon events where convenience and reducing litter are priorities.
How do I prevent my soft flask from leaking?
Ensure the cap of your gel flask is fully closed and test it before you run. Avoid overfilling and keep the flask upright in a pocket or vest when possible.
Maximize Your Running Performance with Soft Flasks
Soft flasks are a simple, practical upgrade for any runner. They help reduce waste while providing convenient, easy-access storage for multiple servings of fuel, and their versatility means they can also be used for other nutrition or even hydration. Lightweight and collapsible, they make storage effortless and fueling on the run more efficient. By streamlining your nutrition, you can focus more on your performance and less on fumbling with individual gel packets.
Whether you’re training for a marathon, tackling a long run, or just looking to simplify your fueling strategy, a soft flask can make every run smoother and more enjoyable. Try one on your next run and experience the convenience, efficiency, and consistency that so many runners rely on.
