as a trial dog its expected to work flat out for a small amount of time ,then its coat is put on and it rests.
If you work a dog flat out every day as hard as the dog can work eventually something will give in the dog. Either the dog will pick up an injury or just burn him self out, all dogs will work through pain and exhaustion just because they love doing the job they were born for but it's a responsible owner that assess the dogs and rests it when required. If you have a working dog you have to slowly increase the dogs stamina and that doesn't include walking as walking and working are very different for the dog. Anyway just my thoughts.
if you then took the same trial dog and worked it for say an hour it would be knackered
couple of days later 2 hours completly knackered
surely after a period of time it would learn and slow down so it could do the whole day
i think that a trial dog would learn to last the day
it would be a rubbish trial dog but could work longer but at a slower pace
i,m no expert but would the trial dog become conditioned to work slower
just a few thoughts