An important thing to remember is that your endurance horse is an ELITE athlete. 
The health, well being (mental and physical), fitness, flexibility, weight, condition, attitude and energy are incredibly important issues. Of equal importance in your training schedule is not only the miles and quality of training you put in but the days you allow your horse to rest and recover to help revive those sore tired muscles from your training sessions.
Some horses do well training several days in a row then having rest days, some prefer one day training then a day of rest. It will be up to you to recognise what suits your horse.
To try to explain this in basic terms, just like people who are trying to build strength and endurance, to do this the muscles are put under pressure and slight damage. The following rest day allows this muscle damage to be repaired and for the muscles to rebuild stronger. If you continuously strain and restrain over and over again you will at some point in time have injury or problems with the muscles because instead of having a chance to repair and rebuild stronger they are actually weakened and more likely to have injury occur.
Never underestimate a rest day for a horse who has had a big long hard hit out - I am sure they will appreciate it.
Often in a training schedule a part of it that is often forgotten is LSD (long slow distance work). Legging up is vitally important to horses new to the sport and for horses coming back from a spell.
It is great to think you have a speed demon on your hands who will fly around the course but if the muscles, bones, ligaments and tendons are not up to the task it will be a very sore horse and sorry owner at the end of a hard ride. Be aware that once you are qualified does not mean your next ride out of novice has to be at top speed. All you have done is 3 x 80km rides and there are alot of miles to go before your horse is considered seasoned. Dont rush, take your time and you will have a four legs under you that will be your partner for many more years to come!
When starting endurance starting at rides towards the back of the pack or waiting till the front runners leave can be an important factor that can help alot with your CONTROL. If you teach your endurance mount that all they do in training is go fast once you get to a ride there is a chance that with the adrenalin all around them 'control' will be out the window. In your 40km and 80km rides waiting behind teaches your horse it isnt a race, it is not allowed to go rushing through the gates and blindly out of control up the road. Walking out the star
t gate is a wonderful habit to teach the horse and help try to keep them calm as well.
LSD work in your training and planning your endurance ride schedule sensibly will slowly build up all those important parts of your horses body.... long slow training sessions thrown in amongst your faster harder sessions are very important. Hours in the saddle (not always doing strenuous work) still helps the horses body become accustomed to carrying the weight of a rider and saddle and helps the horse become use to those many hours it will take to do that first 80km ride with a rider on its back!
Of interest is the fact that printed in an endurance magazine was the ride times of the Tom Quilty 100 Miler, and over the years the Quilty even the top 10 place getters often do the ride in Novice times... so do not feel pressured to push your horse faster than he is comfortable with or ready for once you qualify - remember TO FINISH IS TO WIN in this sport!
There is a saying that it takes 3 years and many a wet saddle blanket to have a 'seasoned' endurance horse. Now that is alot of mileage! So be patient with that partner who is going to carry you all those miles. In those early years build them up correctly and you will have a partner for life, instead of one retired by the time it is 8 years old!
There are also a few things that you can do to help keep your endurance horse supple, soft and listening to you:-
Participating dressage lessons, adult riding club, jumping etc to help keep your horses mind fresh and interested in life with some variety is a great idea. I find my horse can be very one sided with his canter and trot leads and doing dressage lessons or even just suppling exercises teaches him to be more even and balanced and to use his back and hindquarters properly which can be hard to do when you are trotting along at flying speeds alot of the time. These exercises help develop a strong, responsive and balanced horse.
Remember changing leads when trotting is . very important to do. This so the work is spread evenly for the horse and he is not on the same lead all the time which can result in tightness on that side of its body.
Finally regular massage therapy or the likes of bio scanning to relieve those knots, tightness and checking for injuries. Dont leave having your horse treated until it is ALREADY injured or in pain. Regular maintenance sessions are worth their weight in gold and your horse will thank you for it!
I highly recommend Kelley at Performance Horse Therapies for your horses treatment needs as well.
Kelley is one of the most knowledgable therapists I have come across and travels down to Tasmania regularly - feel free to check out her website.
http://www.performancehorsetherapies.com.au/
Hope these few tips have helped :) I think we look after these horses better than we look after ourselves - and so we should!
Happy Trails!

