Caffeine as a running aid is up for debate.

This is something I have been researching over the past few weeks. I am not a coffee drinker, but my ex-nutritionist suggested it a while back as a helpful running stimulant.

The reason caffeine is so hotly debated is because it has drastically different effects on different people. So it really becomes a matter of weighing the benefits of using caffeine vs the costs. In order to do this responsibly, it is essential to understand exactly what caffeine does in the body of a runner.

Some runners swear by caffeine, praising it for its ability to boost energy and increase focus and concentration. For other runners, it can lead to a racing heart, stomach distress, and diarrhea. I believe that it is up to the individual runner as to whether caffeine should be a part of his or her diet. To help you make that decision, here are the facts you should know:


  • said to improve endurance performance
  • reduces our perception of effort through the stimulation of the central nervous system
  • contains high levels of antioxidants
  • possibly enhances fat utilization, allowing the body to spare glycogen stores for later, resulting in more available energy
  • exercise can override the effects of dehydration through urination brought on by caffeine


  • hampers iron absorption
  • benefits are reduced when consumption becomes more habitual
  • creates in acidity in the body (by increasing stomach acid output) that may trigger the release of calcium (an alkalizing mineral) in order to restore the proper pH of the body. Calcium is stored in your bones, so to release it our bones are broken down. This may cause us to become more prone to injury, and there is also less calcium available to play its important role in muscle contraction and relaxation (crucial to running). You can read about this fascinating process in more detail at the end of this post and also here.
  • over time, consumption can lead to cardiac sensitivity, abnormal heartbeats, anxiety, irritability, stomach and intestinal irritation, insomnia, and withdrawl symptoms such as fatigue or headaches

My own personal take on caffeine is: Thanks, but no thanks.

I have never been a coffee drinker, so for me to start solely for the purpose of improving my running performance makes no sense. I also don’t like the idea of anything stimulating my brain. I would rather learn to harness the power of my own mind so I can stimulate it at will (you can read more about your brain’s role in running here).

Alertness isn’t an issue for me because if I feel tired, I don’t run. And since I love running, I tend to also make sleep and rest a priority. As far as antioxidants go, there are many other natural sources such as the ones listed here. So why risk creating an addiction that I don’t currently have?

However, if you do decide to make caffeine a part of your training, the general guideline for maximum benefit is: 4 mg of caffeine per kg of body weight taken one hour before a run. This should have a performance enhancing effect on the body.

Almost every running book I pick up has said something different about caffeine (either as a DO or as a DON’T). I don’t like this because I feel that the ultimate decision should rest with the individual runner based on the effects caffeine has on his or her body.

As writers or nutritionists, we should really just be presenting the whole truth about caffeine and its possible effects, both positive and negative regardless of our personal opinions, and allow the individual to make their own educated decision. This is what I have attempted to do here.


In light of the fact that I will soon be practicing nutrition with 12 real clients, I am going to start taking three day weekends from my blog to keep up with my increasing workload. So my first post of the week from now on will go live on Mondays at 11pm EST (instead of Sundays). This Monday you’ll get to hear about my first music-less 5k race!

Keep sending in any questions you have to  I am working on a couple of good ones right now.

Have a great weekend!