I think any time you go a longer distance, you need to go a bit slower. If your horse looks great after your 2 hour rides ( check the morning after for swelling, heat and attitude ) then you should go for it- but at a slighty gentler pace. Also- I like to give them 10 easy days/ days off before a competition, with a bit longer ride ( 2/3 the distance ) 2 weeks prior. Good Luck ! - Heidi Helly
p.s. Give your horse a week off after the LD too !!