My wife has had issues with nausea after long workouts for a number of years now.

She gave up on running marathons several years ago because after running more than two hours or so, she would feel terrible the rest of the day. Not during the run, but after.

Lately, she has started riding again and the same thing happens. Anything up to a couple of hours, she's okay, but if she tries to go longer, she is miserable the rest of the day.

The intensity of the workout does not seem to be the issue, more the duration.

Has anyone had this issue before? Any ideas on how to keep it from happening?

(And no, she's not pregnant. And, yes, I know she wouldn't have the problem if she would keep her workouts shorter than two hours.)

Thanks for your input.

Mike