Caffeine in Endurance Sports

Our Caffeinated Endurance Fuel contains 35mg of caffeine per 100 calories. Two common questions come up: Why do we make a caffeinated version of Endurance Fuel in the first place? And how did we come up with that quantity? Rest assured, all Tailwind Nutrition products only include ingredients that measurably help performance, not additional supplements for marketing’s sake or trends. Our inclusion of caffeine is no different.

There is quite a bit of research on caffeine and athletic performance demonstrating substantial endurance benefit from caffeine in the 3-5mg/kg concentration range. Caffeine works by mobilizing fatty acids in the bloodstream, which can be burned by muscles. This spares glycogen stores, resulting in greater endurance. The effects can be substantial, in the 15-20% greater endurance range. This is independent of the Central Nervous System boost we all associate with a good cup of coffee, which can help reduce feelings of fatigue and can be achieved with a lower concentration than the ergogenic benefit.

So why that exact quantity? 35mg/100 cal concentration is enough to trigger the Central Nervous System boost and yields the longest productive ergogenic period for the broadest range of people. Also, while 3-5mg/kg body weight is beneficial, more than that does not improve performance, and accumulations exceeding around 500mg can cause side effects like jitters, nausea, etc. It’s important to note that caffeine has a half life of 4 hours on average (this varies person to person – some process caffeine faster, others slower), which means half of the caffeine present in your bloodstream is eliminated in 4 hours, so caffeine tends to accumulate with continuous ingestion. To avoid exceeding concentrations that can cause undesirable side effects, we recommend not exceeding 6 hours of continuous Caffeinated Endurance Fuel use. As noted, the accumulation rate will vary person to person.

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Hello! I just purchased a sample pack and realized some of the endurance fuel contains caffeine. I don’t drink caffeine—it makes me nauseous and jittery. I am trying this new to me product on a long training run, but wondering if I should be concerned and if it will affect my run negatively since I don’t handle caffeine very well.
Tailwind Nutrition replied:
Hi Rachel!

Yes, some of our Endurance Fuel contains caffeinated flavors. They are made with organic ingredients and formulated to help with athletic performance (not as many mgs preserving as a cup of coffee to avoid jitters and overloading the system during sports). Hopefully, the mgs per serving is low enough not to affect you but help you!

Rachel Martinez
Hi , I am running my first full marathon soon. I am planning on carrying several single serve packets , some caffeinated some not. I am concerned the packaging will not withstand the accumulation of sweat and be unusable. Please advise

Tailwind Nutrition replied:
Hi Gary! Thanks for reaching out! We have many marathoners and ultra marathoners that carry single-serving packs with them during their race in a vest, or pack. The packaging is plastic, so the sweat will not break down or permeate the packaging during your race. If you have further questions we are always available via email at


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