Train Smart

Caffeine & Exercise

Sometimes the thought of getting up early for yet another workout sounds horrible, and so we look to a cup of ‘jo to inspire us.  Caffeine is likely the most widely used stimulant for that purpose.  The average caffeine consumption in the U.S. is approximately 200 mg per day (1 mug of coffee).  10% of caffeine connoisseurs ingest more than 1000 mg per day!

It has no nutritional value, but it is often referred to as a nutritional ergogenic aid (i.e., an external aid that improves performance).  It is absorbed quickly, and potentially affects all systems of the body since it is absorbed by most tissues.  Its positive effects include sharpened focus/alertness and glycogen sparing through the augmented use of body fast as a source of fuel.   Are you still baffled as to why there is a Starbucks on every block in every major city!

The question still remains: To caffeinate or not to caffeinate? 

In the 1970’s studies suggested caffeine enhanced endurance performance.  The studies suggested caffeine triggered the release of body fat to be used as a fuel source.  Stored carbohydrates (glycogen) is in limited supply in the body, and your body’s preferred source of energy, so preserving it would therefore increase performance. 

In the 1980’s studies found that caffeine did not alter exercise metabolism!  Although, those studies did not actually measure performance… go figure. 

Recent work has turned the scales yet again in favor of caffeine’s ergogenic effects.  Specifically, 3-9 mg of caffeine per kilogram of body weight about one hour prior to exercise has been shown to increase performance.  In practical terms, a person weighing 150 pounds should consume 200 mg of caffeine, which is equal to about 1 mug of drip-percolated coffee.  These studies observed well-trained or elite athletes however, so the interpretation is a little fuzzy for the weekend warrior.

 There are cautions and limitations, of course:

***Caffeine improves performance for events that last approximately 5 minutes at 90-100% intensity.  Sprint performance, on the other hand, is not improved.  The reasons for this are still relatively unknown.

***There are also side effects of caffeine ingestion that may outweigh the benefits: anxiety, jitters, inability to focus, insomnia, and irritability to name a few.

If you still want to ride the caffeine train, then know that the optimal dose is 3-6 mg/kg body weight.  Side effects are minimized at this dose, and for the elite out there, urine levels are legal at this dosage.

My professional opinion: Experiment!  You may be one of the lucky ones who gets to fill his/her water bottle with Columbian Bold.  More than likely, the dehydration, increased bowel movements, increased heart rate and body temperature, anxiety, and irritability will not prove to be helpful when standing at the starting line of your next marathon.