



🏅 Elevate Your Game with Every Sip!
The GU Energy Refillable Flask is a 5.1-ounce soft flask designed for sports nutrition, capable of holding up to 5 servings of energy gel. It features a high-flow nozzle for quick hydration, measurement marks for precise refills, and a reusable design that promotes sustainability.

K**N
Works well
Great for long run fueling. I make my own energy gel using chia seeds, the seeds get stuck unless I crank the lid as open as it goes, which distracts me enough whilst running that my pace slows. I don't like that, so I think next time I will try grinding up the chias. It would work perfectly with Gu though, since obviously that's what it's made for. It doesn't leak gel, but I think it would probably leak water. It's the perfect size to fit in my FlipBelt, it's pretty easy to clean, and it didn't come with any funky smells or anything. I'm happy with it, and will likely order another so I can carry 2 with me for my first full marathon this fall (I'm slow, so it'll be a long one.)
J**
Good but individual Gu are easier
Great sturdy product everything works great and holds up on long hikes. Refilling can be kind of a pain also if you like different flavors lie I do this probably wouldn’t be the best choice because it holds more than one serving of gu so you would have to purchase multiple. A great positive though with sticking with one flavor is that you reduce trash you have to carry with you.
E**K
Works great!
It works great, not sure what all the negative response is all about. I like that I don't have to deal with empty pouches. I have no problems filling it or using it. I found it to be less messy than pouches. I do not have any problems opening it, it only requires on hand and my teeth are fine. To clean, I recommend soaking it in warm water just to dissolve any gel still in the pouch. It is far and away better than individual pouches. Gave 4 stars because I think its a little over priced.
R**T
It does the job
I like doing triathlons and long-distance cycling and I am cheap, lol. I have never been a fan of the little packages of Gu and trying to keep track of the trash. I also am not worried about the EXACT amount of fuel I intake and am fine with being close enough.But, I find it easy to combine the maltodextrin, agave syrup, electrolyte powder, and flavor in my kitchen aid mixer and let it go. I keep the big batch in a wine purse refill bag. I clean them and reuse them as well and it works well. https://www.amazon.com/6-Pack-Wine-Purse-Refill-Bags/dp/B0195E7COI/ref=sr_1_16?Anyway, these hold the product well and clean easily. The caps do not leak. Although, sometimes the caps get a little stuck shut but I am not sure if I shut it to hard or if the sugar glues it shut. Overall though, it does its job and I like it.
A**4
Gu Flask
Tired of carrying multiple gel packs in your pocket? Worried about the waste and cost of single packs?This is the solution. You can fill up to I think the equivalence of around 6 gel packs.Easy to use with one hand while riding, the nozzle can be twisted by your mouth.Remember to rinse out the nozzle after usage or the drying gel will clog it up.And rinse out any gel that you won't be using within a week or so. The gel will dry in the flask and will be hard to clean. (Hot water and a little soap works, but it's easier to make sure to use it all instead of letting it sit around)
B**A
Not the best design but it does the trick
This holds 5-6 servings of GU or other energy gel. Works well when you fill from the multi-serving pouches (big 1lb bags) that GU sells. The size is perfect for longer activities - if you're taking a shot every 30-45min, this would be appropriate for a 3-4 hour activity like an endurance ride. Pretty easy to clean as you can get a brush or your finger through the opening to rinse out the interior.Cons: The mouthpiece is fiddly to use with one hand. For one thing, both the cap and mouthpiece are threaded in the same direction and neither of them "lock", so when you close the mouthpiece, it also tightens the lid - sounds good. But when you loosen the mouthpiece, sometimes it unscrews the entire cap. This could be avoided with a different design: perhaps the cap should "lock" in place so only the mouthpiece can rotate. Perhaps they could be threaded in opposite directions. Also, the mouthpiece is a hard plastic and not pleasant to screw/unscrew with your teeth. I wish it was a more rubberized texture, like the mouthpiece on a hydration bag, or that it had a mechanism that didn't screw at all, like a cycling bidon.Overall, I'm mostly satisfied with this, but I bet there are better designs out there and probably would not buy again.
S**Z
Very nice for long runs and rides
I bought 2, one for running and one for my bike. I love that I don't have to worry about trash and accidentally littering on course. I wish they came in a smaller size bc I find myself wasting product on short runs/rides. Overall a great solution to the single serving GUs and not that hard to clean.
K**R
DO NOT BUY! Leaky, defective product!
This is the first negative review I can recall leaving in my life. I used this flask one single time. It was a mess, gel was getting everywhere, and I couldn't figure out why. Afterwards, when I was cleaning it, I noticed it was leaking excessively from the bottom "sealed" corner... and then I noticed it was also leaking from the completely closed lid. I received a water bottle that is literally leaking from both ends, and yet I can't return it or get refunded to to their policy. Complete waste of money.
Trustpilot
2 weeks ago
1 week ago