NB. Lucky to be here

[BurnitBlue]

Have you not seen video of people in sleep research labs? They fidget! (I know I do; my sheets get worn out...)

And there isn't much hydrostatic gradient when horizontal. I don't think the tiny seat recline in airline cattle class makes much difference!

Mike.

Yes I recall seeing such things on the TV. Must be exhausting. Often wondered why. Must be a Darwin thing. Fidget or get removed from the gene pool.

Whats this about hydrostatic gradient? Is it an issue or you winding me up?

 

[mjcoon]

Whats this about hydrostatic gradient? Is it an issue or you winding me up?

Usual caveat: I'm not a doctor. But I understand that pumping blood back up your body from low in the body depends partly on one-way valves in veins in the legs. These work like some domestic siphons by turning random movement into a one-way flow. But if legs are not moving you don't get the effect.

Although your heart generates pressure in arteries it is all dissipated in the capillaries, so return flow is a problem. When you are lying down there isn't so much gravity working the wrong way.

Mike.

 

[Twister_Ken]

But why on long distance flights? Why not in bed when zonked for eight hours beauty sleep?

In part because in bed you're horizontal, so less pressure is required to keep the blood flowing. Sitting still, slightly cramped, with your feet and calves below the level of the rest of your body can cause the blood down there to move very sluggishly or stop altogether. Hence, in my view now, its wrong to try and sleep in an economy style airline seat. Stay awake, do leg lifts, etc, regularly or walk around the cabin from time to time. Yes, you'll arrive cream-crackered, but it's safer to catch up with sleep at your destination when lying flat in a proper bed.