Things that make you go hmmmm.
The 30 minute workout I’m referring to is that cutie on a treadmill barely breaking a sweat while sucking on her designer water bottle and there isn’t enough sweat to ruin her makeup. Yesterday, I spent 30 minutes working on my plane and it required a fresh shirt and a bottle of water. Did I mention it was hot and humid.
Correct medical terminology is insensible, not insensitive perspiration and that plus respiratory loss which amounts to about a loss of 0.5 to 1 quart of water per day. On a 4.5 hour flight, that amounts to less than a can of soda. Hardly enough to be deleterious.
Eating while flying isn’t the issue. Grapes are high in sugar which is why they are so well suited to making wine. A cup of grapes has around 20 grams of sugar. A pound of grapes is about 2.5 cups. If that lovely bunch of grapes was let’s say was 2 cups, that’s over 3 tablespoons of sugar. Without something to back that snack up such as a complex carb, blood sugar can drop when the body releases insulin. If only the sugar from the grapes is ingested, it can cause a spike in your blood glucose level, then a crash as the pancreas releases insulin. That starts a reflex cycle, although not immediate, where the liver supplies glucose in response to the low blood sugar so there can be a period of hypoglycemia before returning to homeostasis. This of course depends on quantity and period of time of the grape consumption. On the positive side, grapes are a fluid source.
We can agree to disagree because I don’t agree with your counterpoints. Just my point of view but I think dehydration hype we see everywhere fuels the belief we need to be at a max hydrated level 100% of the time. Water sales are big business. And you wonder why I sound a bit cynical. We typically go 8 to 12 hours at night without fluids, yet start the day without being dehydrated. Yes, we need fluids but we are not dehydrated as the day gets started.
People do get dehydrated. It is serious. My main contention is a few hours in the cockpit isn’t going to change a hydrated person to a dehydrated person. And I guess I’m aware of physiological changes that occur. To be fair, I’m a retired hospital director of pharmacy and clinical pharmacist.
All this being said, I throw a bottle of water in the plane for long flights. Comes in handy when I want to wet my whistle.