Question - Fluid intake

Today's question came from the Trochu Valley School.

You measured your fluid intake each day as you trained and we wondered why this is important and how that impacts your trek up Everest?

Lucille conveyed her explanation to me, Ted, and I will paraphrase it here.

Have you ever noticed that the air is a lot more dry in the winter than it is in the other seasons. Well, on Mt. Everest, the air is extremely dry. Every breath you take robs your body of a little bit of moisture, that is the fog on your breath as you exhale in the cold. Hopefully you don't work so hard that you also sweat a lot on top of this, because in addition to making you cold, excessive sweating is also additional loss of moisture.

Also, as you go higher on the mountain, and the oxygen gets thinner, your body produces additional red blood cells to try and carry as much oxygen as it can get a hold of, and your blood actually gets thicker. If you allow yourself to get dehydrated, you could develop blood clots as well. Those are not good for you.

To keep up with this loss of hydration, they will have to drink about 5 liters of water per day, and up high on the mountain, they will have to melt snow to get this water. Lucille has never been particularly good at drinking enough water as you noted in her training blog entries, and she has to remind herself to drink more to stay healthy on the mountain. In recording her fluid intake, she was reminding herself to try and drink more. If you didn't figure out the other acronym there "RHR", means Resting Heart Rate. She also measured her blood oxygen saturation, but I don't believe she recorded that on her blog. The combination of these factors would give her an idea of whether she was training properly, or maybe over training a little bit. She would compare all these readings with how she was feeling, and she continues to monitor all of these during her expedition.