If you go to www.aerc.org and click on the “education” tab there’s tons of information and links there, and the links in the thumb-tacked post at the top of this page are great too.
In general I will tell you that horses are burning the hay/forage/grass that they ate a day or two prior on the day of ‘the big effort.’ So it follows that our job is to make sure that they have plenty of hind gut fill (i.e. hay and grass) in the day or two leading up the big trail ride or endurance ride.
We can certainly get into all sorts of details about equine nutrition, electrolyting, etc., but the horses that tend to do the best metabolically are those that “tanked up” prior to the ride, either at home, on the trailer ride, or in the camp before the ride – or some combination of the above.
Hope that helps!
–Patti