What exactly do you mean by 'on the bit' here?  Do you mean "A perfect 
contact" that "is possible only when the horse is in absolute balance, 
carries himself, and does not seek support from the reins."  In which 
case "It may then be said that the horse is 'on the bit.'"  (As defined 
by Podhajsky, and is what most dressage riders mean when they say 'on the 
bit').
Or do you mean that all the horses were in some way leaning on the bit 
and pulling on the rider's hands.  In which case most riders would 
describe that as being either "behind" the bit or "above" the bit 
depending on whether the horse is doing this by sticking its nose up in 
the air or is overbending at the poll and has its nose pulled to its 
chest.  (Two ways of going that I have noticed are very common at 
endurance rides, especially at the start.)
> I dawned on me 
> then that not only did I need to warm up, but I needed to get my 
> horse round and flexing before the start.  Guess I will be getting up 
> a little earlier next time.
If what you want is for your horse to be truly 'on the bit' rather than 
just leaning on the bit.  The time to do this is not in the hours before the 
ride but rather in the months before the ride.  But a good warm up is 
also beneficial.  Many dressage riders will do this by longing the horse 
(only of any benefit if the horse is bitted up in side reins) so that the 
horse may round and flex without having to counteract the weight of the 
rider.  Others will do it by warming up the horse with its neck stretched 
out and the head "down and low" but I wouldn't recommend this as few 
people can do it properly, keeping the horse round, but rather the horse 
ends up just dragging its hindquarters along behind.
Just curious as to what you meant by "Talk about being on the bit."  My 
experience at endurance rides is that maybe 1 in 50 horses could be 
described as being 'on the bit'  Many of them start out behind the bit 
with their noses pulled to their chests and then during the course of the 
ride, as they tire, they drop their backs and get above the bit.  SOme of 
them start out with their nose stuck up in the air and are above the bit 
for the whole distance of the ride.
Others (myslef included) will, for much of the ride, allow the horse to 
go along with little or no contact on the bit at all and just ride on a 
loose rein using contact with the bit only for preparation for changes in 
direction or pace or to assist in the negotiation of a particularly rough 
or tricky part of the trail.
kat
Orange County, Calif.