Perpetuem with caffeine

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Perpetuem with caffeine

Postby runandrunandrun » Mon Aug 15, 2011 9:20 pm


I was wondering what issues there may be with using the Perpetuem with caffeine (caffe Latte) for running ultra's as the sole or predominant source of food.
It is often stated that caffeine is a diuretic, however a study in Nature on tea suggested that caffeine only acts as a diuretic when levels exceed 300mg in one sitting (they seemed to mention that the study they sited did not just focus on tea), in which case the 25mg per serving that this Perpetuem contains would not be a problem (also given i will be drinking reasonable amounts of water in addition to the solution) ... 2489a.html

However if taken as the sole fuel source for say 24hrs this would mean 600mg of caffeine over this period, which is above the 300-400mg stated as a common amount consumed in the UK (not actually that high given this would be a few times a year occurrence as opposed to once a day).
Could there be some other impact on the body from consuming this amount of caffeine over the day- mental, physical (bowel or bladder or other)

What are the company opinions on this issue, given Perpetuem is advertised as a sole or predominant source of food for ultras?
Is there anyone who has used this product for a sustained period of time and did they notice and positive or negative impacts.
Another consideration I had was that the caffeine may lose its effectiveness as a stimulant late in the night (when you might need a pick me up) if you had been taking it all day.
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Re: Perpetuem with caffeine

Postby steve-born » Tue Aug 16, 2011 10:17 am

Hello runandrunandrun -

I am in full agreement with you that the amount of caffeine (12.5 mg) in one scoop of Perpetuem is insufficient for the overwhelming majority of athletes (if not all athletes) to have diuretic effects.

As far as caffeine's "shelf life"/activity in the blood, the Coffee Science Information website states that caffeine is fully absorbed by the digestive system in approximately 45 minutes, with the peak of concentration of caffeine being 15 to 120 minutes after it is consumed. Typically, caffeine stays in the body for anywhere from five to nine hours.

Everyone's tolerance level with caffeine is different so it's impossible to give a "one size fits all" diagnosis (and I use the word "diagnosis" loosely) on how one will respond/react to caffeine's effects. I know that when I consume too much caffeine it definitely affects my Central Nervous System (usually in an unpleasant way), and it does tend to exert a laxative effect in many people when taken in large doses.

I know of many athletes who have used the caffeinated version of Perpetuem as their sole fuel in 24-hour races with no issues whatsoever (aside from the fact that consuming the same thing hour after hour gets a bit boring). Personally, if only for some variety in the menu, I suggest that one use Perpetuem as their primary fuel - roughly 2/3 - 3/4 of the time - with any of the other Hammer fuels used to fulfill the remainder. All of the Hammer fuels are compatible with each other so it's fine to "mix and match" them.

Lastly, if one is a habitual coffee drinking (or consumes caffeine/caffeinated beverages consistently) they will have built up a tolerance to it as compared to someone who has not consumed caffeine for about 2 weeks (perhaps more) prior to an event. Personally, I couldn't imagine giving up my morning coffee in order to garner a small ergogenic benefit; I simply have to have my cup of coffee in the morning!

I do not believe that the fairly minimal amount of caffeine in the caffe latte flavored version of Perpetuem will have any negative effects on performance, nor will it exhibit truly noticeable (if any) diuretic effects or dramatic CNS-stimulating effects, at least not for the average-size athlete. For light-weight athletes, especially those who do not habitually consume caffeine? Yes, it may very well provide a bit of a boost. For most of us, however, it may not be enough caffeine to provide a truly noticeable boost.

I hope this information is helpful!

Sincerely -

Steve Born
Fueling Expert
Event Sponsorship Coordinator
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