Soft Flasks for trail running: light, compact and practical

When trail running, you want to carry a drink without sacrificing comfort. A soft flask molds to your body, takes up less and less space as it empties, and prevents the annoying sloshing you often experience with hard water bottles. Whether you are training for a short trail or preparing for an ultra-marathon, a good soft flask makes hydration on the go easier.

Which soft flask suits your usage?

The right choice depends mainly on where you want to carry the flask.

For a running belt We recommend a flat soft flask. These models lie comfortably against the body and prevent pressure points while running. Moreover, they slide more easily into the pockets of a running belt.

Do you use a soft flask as extra or third bottle in addition to the standard flasks in your race vest? Then preferably choose a model with a locking cap. This prevents the bottle from leaking while traveling when carried loose in a pocket or backpack.

Why do trail runners choose soft flasks?

Soft flasks have become the standard in trail running and ultrarunning. That is not without reason:

• Less movement and sloshing while walking
• Compact to store when the bottle runs empty
• Lightweight alternative to hard water bottles
• Easy to combine with racing vests and running belts
• Available with various drinking systems and volumes

For longer distances, you can combine multiple soft flasks to stay flexible with water, sports drink, or electrolytes along the way.

What volume do you need?

For most trail runners are 250 ml to 500 ml Soft flasks are the most practical choice. A smaller flask fits more easily in a running belt, whereas a 500 ml model is often the standard size for race vests.

Are you running longer distances or are aid stations scarce? Then an extra sealable soft flask can make all the difference between carrying enough to drink or running out along the way.

Frequently Asked Questions

Can I use a soft flask in a running belt?

Yes. For this, preferably choose a flat model that lies comfortably against the body and moves less while walking.

Why choose a locking cap?

A locking cap prevents unwanted leaks when you carry the flask as a spare bottle in a backpack, race vest, or waist bag.

Can I use sports drink in a soft flask?

Yes. Most soft flasks are suitable for water, sports drinks, and electrolytes. However, rinse the bottle thoroughly after use to prevent odors and buildup.

Combine your soft flask with the right equipment

A soft flask performs best when paired with a well-fitting race vest or running belt. Also check out our collections of trail running backpacks, running belts, and hydration accessories to complete your gear for training and races.