Training difference Mountain to Road

[boots2000]

This is sound advice-
I might also add that often mtb racers neglect flatter tempo work on a road bike. Flat tempo can add a lot of depth to an mtb racer's game. It is not all about climbing. You will go faster when you can apply power on all portions of a race course.

To answer the OP. A good training plan for MTB will be a massive but structured stack of road miles/intervals/threshold work, with a bit of offroad skills/handling. The good road plan will essentially miss out the off road bits. That's it.
The best XC mtbers train ~85% on road. (Maybe on their mtb, maybe on a training/road bike)

Unless you are very very lucky in your location and the trails around you, it's almost impossible to train properly to race MTB, off road. I live in the midst of a massive network of trails/dirt roads/tracks/footpaths, and I still struggle to find anywhere to do *proper* intervals, or threshold work. There are too many breaks/obstacles/junctions. On the road, I can do intervals/threshold stuff 500 metres from my front door.

And you will find once you get your head round road training, your mtbing will come on in leaps and bounds.
The surges and pace changes that are killing you on the road will become useful tools on the MTB, pace changes *hurt*, get better at them and you'll do better at mtbing. You can have a much better go at breaking the people you were finishing with.

[KWalker]

One thing I like to do is do a really hard effort right before some technical stuff to simulate having to bike handle while recovering. Much harder mentally than you think.

[drider85]

Season is in full effect here and I am beginning to see the fruit of my labor paying off. I have not added more hours of training compared to seasons previous. I have dropped 2 mountain days and added one longer tempo road and short max speed sprint workout. Currently I have my time split with 2 road days, 2 CX/dirt road days and 1 or 2 mountain days depending on races and fatigue. I have found my riding improve both in crit races and my mountain racing. I feared that less time on the trail would lead to loosing the feel for the dirt. That has not been the case. I have keep 1 or 2 day a week on the trail and I have seen my times improve. The keystone result is a 2nd place in the "A" group at our local road training series. It seems so far to me the best logic for mountain racing is to train more like a road rider.