Wednesday, August 4, 2010

Caffeine on the run? Everything in Moderation

In Phedip 240, Steve Runner brings up a great topic for discussion, the relative value of caffeine for the recreational runner. He covers a few basic science studies on the subject and I think he comes to an appropriate conclusion, which is that moderate doses of caffeine may directly improve your performance on short distance runs and may at least reduce your perceived effort on longer runs. There is plenty of research on the subject and for more of a sampling, check out PubMed.

That said, I must caution against the dose suggested in one of the studies Steve mentions. The first study was placebo controlled and used 5 mg/kg as a dose. They found that both recreational and well-trained runner improved their performance by about 1% over placebo. The second study mentions use of a 3g of coffee (150-200 mg caffeine) dose had a similar, modest improvement on performance. I couldn't find the link to the third study Steve mentioned, and I had to go back and listen to make sure I didn't miss something, but they used a 15 mg/kg dose in their trial.

Now, if you are not much of a caffeine user, let me put that in some different terms. I weigh about 180 lbs. divided by 2.2 equals 81 kg. Multiply by 15 mg/kg and my dose for that study would be 1,227 mg of caffeine. If you visit you will find an exhaustive list of the caffeine content of various beverages. To participate in this study I would have to drink one of the following:

  • 27 Diet Cokes
  • 15 Red Bulls
  • 7 Grande Cafe Mochas from a popular coffee franchise
  • 49 cups of green tea (8 oz.)
  • 56 ounces of black coffee
  • 16 shots of espresso
Now, I think you can imagine how you might have more energy after a 15 mg/kg dose of caffeine. That said, I drink coffee but I think that might be a bit much for me. Furthermore, remember that the study in question was performed in a controlled environment that presumably had trained professionals monitoring the participants. Which is a good idea because doses like that are enough to induce arrhythmias like atrial fibrillation, which I have seen happen in otherwise healthy young people due to large caffeine doses (and alcohol).

Be safe out there, and always remember to use in moderation!


  1. Yikes! I must have read the summary wrong: here's the link: let me know what you think and I'll announce a retraction on the next episode of Fdip!! I love coffee...but YIKES!!! - Steve

  2. 15 mg/kg certainly is a lot, and not out of the realm of possibility in a controlled, laboratory environment, but definitely not recommended for pre-race use.