Quick update to my reading, which should have been obvious to me, but wasn’t until I saw this chart:
I’ve always told folks not to hyperhydrate with glycerol because of increased risk of hyponatremia if it goes poorly, and just thought that it might result in increased water retention to the point of hyponatremia. What should have been obvious to me was that sodium excretion increases with glycerol loading because of the fluid retention. Kidneys excrete the sodium to try to bring blood sodium levels back to normal.
Implication:
Don’t glycerol load without sodium.
Scratch that… don’t use glycerol at all. It’s banned by WADA for being a masking agent, even though it has no such effect, even in concert with sodium loading. Glycerol is a less potent blood volume enhancer than sodium.
Okay back to sodium loading… my goodness some of the literature uses high concentrations of NaCl. 7.5g per liter!
GOULET 2017, Salt + Glycerol-Induced Hyperhydration Enhances Fluid Retention More than Salt- or Glycerol-Induced Hyperhydration.pdf (906.9 KB)