Bonking

Have you ever been exercising and experienced one or more of the following symptoms? Dizziness, confusion, extreme fatigue or even passing out? It's real. This info sheet explains more. Sugar supplied to brain comes from the liver's production of it. When the liver is deprived of the energy required to make or convert sugar for the brain, bonking is the result.
It can be a serious thing. When I looked it up, the online encyclopedia Wikipedia--which isn't always reliable--said it's a vernacular word for having sex. (I thought that was "boinking." But, lo, in a subsequent Google search for "bonking" images, there's a picture of two lions in a compromising position.) So just to be clear, this is about your body running out of fuel during exercise. It happened to me one day last week in spin class. I assure you I wasn't doing what the lions were doing. In fact, I felt like throwing up.