Originally Posted by
calyco
During the 20 mile, I would stop at 10 to take a break and chug like 10 ounces of water. 2-3 times I felt light headed at the 10 mile break stop.
What were the circumstances? It's normal for blood pressure to drop a bit while resting after exercise and if you then get up at all suddenly that can lead to a feeling of light headedness.