Post run nausea

I'm asking this on behalf of a friend who is training for a half marathon.  The training is generally going well, but every time she runs for any longer than 1 hour she feels really nauseous afterwards.  Has anyone else had this in the past?  Would anyone know any likely causes and how to prevent it?

A friend, yeah, likely story

is she eating before running?

hydration?

how fast??

No she's not pregnant and isn't running too fast.  I don't think it has anything to do with when she eats beforehand.  The feeling of nausea doesn't start until a few hours after her long run.  At first she thought it might be dehydration or low electrolyte levels, so started to drink a sports recovery drink after the long run, but that hasn't helped.

After a very long run (22-24M +) I do sometimes feel a bit nauseous (and no, I'm not and wasn't pregnant, etc.).  I make sure I have something, even if it's just chocolate milk and then snack on plain foods for the next couple of hours so that I've replenished my glycogen stores.

I have had this many times after a long run and I put it down to your body going into shock as it is just not use to it. I have actually been sick a few times after a long run and after I have been sick I feel fine again.

Also after a long run my sense of smell is hightened which is weird. Does anyone else experience this or is it just me being weird