I’m no Energizer Bunny®, I admit, but I’m not a quitter, either. That’s why I take it personally when my body lets me down—as it did not long ago, when I found myself struggling to keep going during the final hours of a trip. The combination of hard work and hot sun took its toll, and though I’d been drinking and snacking all day, my batteries had definitely suffered a voltage drop. Then the Old Woman got in my face in a big way, slowing my progress to a crawl. So I did what I had to do. I stopped to have a little something to eat and drink. Then I took a short break till I got my second wind. It meant that I’d be running behind schedule, but I really had no choice in the matter. The alternative was the bonk.

Also known as “hitting the wall,” this is shorthand for complete physical collapse. (A word of warning is in order here. Bonking often means something quite different on the other side of the Pond. Context is everything.) The signs are unmistakable. Your muscles go slack—in the unforgettable words of legendary sports commentator Phil Liggett, you feel like “the elastic has snapped.” Worse yet, your mind wanders repeatedly from the task at hand, leaving you with an eerie and not altogether unpleasant sense of detachment. This can be dangerous, particularly when your life’s hanging in the balance.”I don’t care what happens next” is not a mantra for survivors. The bottom line? Bonking can ruin your day, and—it hurts to say this—if my experience is anything to go by, the danger increases as you get older. In short, the elastic gets a little less resilient with every passing year. OK. Life’s unfair. But what’s the alternative? A long snooze in the La-Z-Boy®? That’s not for me, thanks. So after my elastic snapped a couple of times, I figured I’d better get to know the enemy. Two urgent questions headed my list: Why do we bonk? And what can we do about it? Read more…