Ultra endurance liquid (Hammer Perpetuem)

If I understand correctly, you’ll be consuming 25mg of caffeine over 2.5 hrs. That’s very little, and the effect will likely be negligible. About a tenth of a cup of coffee.



I put my water bottles in the freezer half full of water. I add the Perpetuem before my ride and top off with water. Than 3 hours later it’s still cold and I just need to shake it up real good to finish mixing.

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Basically a decaf coffee… but if I’m taking say 4 of these bottles, does that caffeine that’s getting distributed through my body have a “long term” effect within that given ride. And if the “benefit” is so negligible, why even advertise or make a product like so?

I have used Hammer several times over the years, always hoping it would work. It never did for me. From what I found, the biggest disadvantage is that you need to stick within their ‘system’. If I didn’t do that, I had major GI distress. I prefer Skratch or OSMO, and SIS or real food- even portables. Hammer was the magic nutrition bullet that kept misfiring for me.

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The studies I’ve read on the impact of caffeine indicate that the minimum dose needed for a measurable performance response is 3mg/kg. So for a 70kg athlete, thats 210mg.

4x25mg over 8 hours will do very little.

The reason caffeine is included is partly marketing, and partly an assumption that people will be consuming more than the indicated amount, or combining with other products containing caffeine.


What exactly do you mean stick within their system. I find it works ok but with some stomach pain at times maybe when im pushing too hard.

Has anyone used the endurolyte tablets and what exactly do they do. Im taking SIS electrolyte drink at the minute but find it very sickening after 10 hours + For eg would taking tablets and drinking water be a like for like replacement for the SIS Electrolytes drink??

Just as an FYI, I used hammer for a long time previously as well and it works, but dont buy into the marketing that there is any kind of sustained complex carbs. Its just maltodextrin which is not a true complex carbohydrate and broken down and absorbed at a rate similar to glucose.

N=1 here, but perpetuem gave me GI issues and I didn’t like the taste. Soy protein? Pass.

I like Skratch a lot, but it’s tough to fuel with. Heed is OK, but I like Skratch better for hydration. Right now I’m fueling with Honey Stinger gel and Skratch. I’ve tried Maurten and Beta Fuel, but not sure about them. Tailwind is my next try.

I like Recoverite (whey isolate, glutamine, carbs, good flavor). Hammer gel flavors are good, and I alternate between those and Honey Stinger whichever is cheapest.

I’m hoping Tailwind works for me. (Not a fan of the recovery drink ingredients, will stick with Recoverite or home made).

I’m a big Hammer Perpetuem fan and user. It just agrees with my stomach while other brands (like skratch) give me GI distress. I mix the caffe flavor with one Cola fizz and it tastes incredible. I usually make a concentrated mix in a 1 liter bottle based on how long my ride is (2:30-4:00). This is the ONLY fuel I use with maybe a few hammer gels thrown in whenever I’m in the mood for it. I did an MTB 100 over 9 hours on nothing but Perpetuem and a handful of gels. For hydration I use hammer electrolytes in a backpack. I never wanted or needed anything else.


Wish I could use Perpetuem, I love the concept, and it used to work for me 10+ years ago, but I can’t keep it down now. My stomach revolts with every flavor, and I generally can use most products.

Hammer Products
Perpetuem - can’t use as I will likely vomit
Hammer Gel - Good, no problems
Hammer Hed - works, but I don’t like the flavor
Hammer Fizz - works!

I have either gone with rice cakes or cliff bars and chews and whatever drink that is on the course.

I don’t think I saw it mentioned yet but Infinit does an endurance drink that is similar to Perpetuem, I’ve not tried it personally, but it is generally well received.


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Interesting! I have been using Hammer products for almost 20 years and mainly because of the complex carbs vs simple sugars (glucose/fructose) argument. Where have you seen this about maltodextrin?

FWIW: One of the elite nutrition coaches that spoke recently to our club talked about the importance of the glucose/fructose consumption during races for fast absorption. It obviously raises the question about Hammer Gels since they list neither, just maltodextrin.

You are supposed to stay within their product line. When you stray, you risk GI distress. I found at any endurance event, it was a major logistical challenge to use just their stuff, so I bailed. I also didn’t think it was worth the effort, as I didn’t see any major improvement nutritionally.

So true! I used Hammer for a year but tried Skratch because all of the hype. My body revolted but I kept diluting the Skratch mixture until my body could handle it. After a couple weeks or so it’s was sorta ok, but I was well under the recommended amount. Finally, I gave up on Skratch and went back to Hammer.

Sure enough, then after 2-3 weeks of Skratch my stomach didn’t like Hammer anymore, grrrr. However, after about a week or so of diluted mixture, I got used to Hammer again at full strength and haven’t turned back.

Had a similar problem when I tried to introduce Cliff Bloks on long rides instead of Hammer gels, ugh, bad stomach issues. So now I’m Hammer everything and have no GI distress. There is something to sticking to one product line as your body gets used to the ingredients.

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Maltodextrin is a chain of glucose molecules. Maltodextrin is produced from corn or other starches.

After another 6 months of using Gu Roctane energy drink mix I’m not going back to Hammer Perpetuem. Versus Hammer, Roctane provides just as much fuel IMHO, no mixing issues, and absolutely zero issues consuming what tastes like flavored water. I fill both bottles with Roctane, so about 800 calories and zip lock baggies for the water bottle refills on longer rides.

Thanks Bill. I think Hammer would argue that a chain takes more energy to break down than individual molecules and therefore avoids the highs and lows of pure sugar dosing. [as you know, Hammer got their start and still remains known for their ultra-endurance event focus]. But as I have shifted my interest/focus to shorter stuff (spirited group rides and racing, for example), I’d be interested to know whether there @redlude97 had seen any actual research to show that maltos absorption was the same as glucose/fructose as it would change my (and others) fueling strategy during these events/activities.

As for the mixed reviews on Hammer’s flavors, I get it and thanks for the Roctane mention. While I use many of Hammer’s products, I actually mix their flavorless Sustained Energy with Heed, for example, to minimize that product’s sweetness.

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  • His name is Brian (not Bill).

Coming from a large family, learned at an early age to respond to any reasonable first name :rofl:

Bob, you can make your own endurance energy drink with maltodextrin (glucose) and table sugar (fructose). There are several threads about it on the forum, and here is a random web link: https://www.climbingnutrition.com/supplements/make-your-own-sports-drink/ where you can see it includes an interesting table on different ratios of maltodextrin-to-sugar. While I’d be interested in reviewing research, it seems to be summarized in that table.


Absolutely. Hammer seems to be more sensitive to this. I stuck with Skratch and Osmo and its worked great for me. Its always an experimental process and all this goes back to why you try it in training…

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I’m a huge fan of Hammer but Perpetuem (liquid) doesn’t sit well, which really surprised me since I tolerate their gels and HEED very well. Your SE reference has piqued my interest in mixing with HEED; what ratio are you mixing? 1:1?