You may have heard the analogy: You start off every race with a box of matches. Every time you make an effort, you burn a match (or two, or three). When you've used all your matches, you're done. Knees fall off, collapse, lose. Sprint up out of the swim: matches burned. Surge out of T1 on the bike to impress the crowd: matches burned. Power up that hill: matches burned.
In this article, we'll look at the physiology behind the matchbox, and then discuss the relevance to endurance sports. Understanding this piece of science is critical to your race pacing.