Synaptic Hydration Belt

(7 customer reviews)


The Synaptic Hydration Belt has a conical shape combined with front and back carrying capacity for a balanced load and a comfortable fit. This water belt is so balanced it won Ultra Running Magazine Top Pick for stability. Store a hat, beanie, gloves, jacket, or even trekking poles with 2 shock cords on the front pouch. The Synaptic hydration pocket is also interchangeable with the Lumen 600 2.0 light belt to suit custom hydration and lighting needs.

UltraRunning Magazine Top Pick!



ErgoFit Waist
Recommended Use:
Racing and training; 1 hour between refueling stops.


• Dual-sided adjustment for good sizing range with single speed hook access for taking waist belt on and off.
• Center front pocket is large enough for cell phone or energy foods with tuck away jacket straps perfect for extra clothing or Z-poles.
• Angled minimalist bottle holster for easy right handed access. Bottle rides close to the body for a comfortable stable ride.
• Synaptic is an MBS™ belt.  Back is compatible and interchangeable with a Lumen 600 front for a hydration and illumination combo.
• Small flat zippered pocket next to holster to secure keys or other essential items.

Fit: Unisex
Size: Universal
Color options: Luminous Blue or UltraRed
Hydration (included):  1 x UltraFlask 550
Capacity: 50 c.i.; .85 L

Additional information

Weight N/A
Dimensions N/A

Waist Belt



Fluid Capacity

550mL UltraFlask bottle

Product Weight (lbs)

Total Volume

34.2 c.i. (.56 L)


7 reviews for Synaptic Hydration Belt

  1. Tina

    I take this belt with me everywhere. Whether it’s a short walk or longer run. It holds just the right amount of water. I love that the bottle is so soft that I can suck out the air half way through and squish it down to reduce sloshing. I put my keys in the back zippered compartment. In the front, I like to carry my cards/ID (there’s two inner pockets for this). I always listen to my music and the front pocket fits my phone perfectly. I usually start my run out with a light jacket and then take it off and loop it through the shock cords on the front of the pack. Sometimes my jacket is heavier and I still don’t feel a bounce when it’s attached. It’s awesome!

  2. Kevin Zanker

    I absolutely think this is the best hydration belt. I liked my previous belt and did not like any of the alternatives until I found this one. No issues filling up a regular water bottle and having stability. I wear the belt for all my long training runs and races from 10K to marathon.

  3. Brian Horton

    Overall the belt fits comfortably with minimal bouncing. I did notice that on warm days when I am perspiring heavily, water does collect in the front pouch. Definitely use ziplock bags if you want items in the front to remain dry. Two issues with the pack. The first is the very small pouch to the left of the water bottle holder. It is virtually useless. I typically carry ID when running, the pouch is so small it will not accommodate my drivers license. The second issue is the loops designed to hold the excess belt. For reasons that escape me, the belt loop holders are stitched in place and can not be moved. If you have a larger waist, the excess belt material can not reach the holders and they just flop around while running. I would encourage Ultraspire to increase the size of the small back pocket and do not stitch the belt holder loops in place. Thank you.

  4. Naz

    A very good belt. Got the chance to use the belt for trail running. The belt secured to the waist with little to no bounce at all. My waist is about 27”, I noticed the belt is slightly loose but good enough though. I can say that its an excellent choice. Not like other belt that keeps on bouncing. Good job done by Ultraspire. I owned the speedgoat and now the synaptic waist belt. I will purchase all products from Ultraspire next time since they make good quality running belt. It did not disappoint me.

  5. Paul (verified owner)

    First, the Soft Flask has very good flow. Much more than a standard water bottle. Second, the belt holds well without being too tight or bulky.
    I have used it only Nordic skiing and for a few easy runs, but it worked well. It works better than any other belt I have tried(Amphipod, Salomon, old Camelbak). I took a chance on this one because I like the belt on my Lumen 600 so much.
    Last, the front pocket works well for phone and gloves.

  6. Giff

    Super comfy, incredibly secure, well ventilated and easy to dial in a perfect fit. The integration with the Lumen light series is a great bonus and the bungee system on the front is perfect for keeping a wind layer handy in the mountains. My only suggestion for improvement would be a slightly larger/stretchier front pocket to carry a bit more gear and/or a smartphone.

  7. Marjorie (verified owner)

    Better than any other waistbelt hydration system I’ve tried. Stays in place, easy access water bottle, holds the things I need on a trail run. It’s a superior product.

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