I am sorry you were "chewed out" but making a horse canter until exhausted is NOT what join up is about at all. It is all about dominance and submission. It is NOT lunging until the horse is too tired to do anything else - it is about forcing them to pay attention to you and presenting yourself as the dominate critter.
You might ask who taught me how to join up a horse - and have every right to ask that question. You don't know me from a whole in the wall. I had Monty Roberts teach me in person - with my horse, who never once cantered while being asked to join up by Monty Roberts in front of a thousand people. He trotted and walked for about ten mintues before joining up with Monty Roberts.
Monty Roberts loved it because he rarely had a demo horse who would work in front of that big of a crowd with a stranger (him) and let Monty show that it is NOT all about the speed, just the posturing and body language. It is so much easier to work a join up at a trot than a canter - I do it all the time.
The filly I mentioned above cantered a bit, but mostly she just pranced about. Being so young, she had no problem accepting that I was dominate. She was a true joy to train to saddle several years later because never in her life did she ever think that humans were to be challanged.
Do most horses canter during join up? Yes. Should you canter a young horse for long periods of time in a circle? No. Done under ideal conditions, there is no reason for a horse to do more than an easy trot - by no means are you chasing them down into exhaustion.
Can you get a join up by chasing them into exhaustion? Yes. In fact, just came from a session from heck with a stubborn filly who took a bit over an hour, half of which was spent at a canter, the other half at a trot before she would join up. She was tired, yes, but exhausted? No. Stubborn? Heck yes.
She was walked for ten minutes after join up then turned out to roll. After her roll she took off to make a couple laps about the arena at a gallop before comign back to her person to be caught. She was by no means exhausted.
I was rightfully corrected when everyone got upset with me, and it does not bother me in the least. The join up method that I was using was a faulty one at best, and I put my horse in danger by playing hero at a time when I should of been playing student.
I do realize that a horse should not be worked into exaustion to make a horse so tired that it just gives up, and that was where I was calling myeslf out in the below post. It is not
in any form correct or the easiest way to do things for you or the horse.
However, this seems to be the way that most people do it, and thus- I generally discourage join up all together unless you are working with a professional. Already knowing OP's position, I feel that is best for her to not join up with the specific colt that she is working with because he is not disrespectful, he is fearful. And he must get over his fear for people before I think that it is safe for him to be joined up with because he sounds like the sort of horse that is all reaction and no thought process yet. I see him very easily trying to scale the roundpen or crashing into it, due to his fear.
When I attempted to join up with my mare back those few years ago, I did not continue to exhaust her until she gave in to me- she had been going at a continuous canter without any sign of slowing to a trot for me for almost an hour, and that was without me pressuring her to move at all. She was simply not going to give in to me, because she hated people. And for good reason, as she had a less than stellar introduction to humans, starting with a cruel man who used a sketchy-at-best method incorrectly to try dominating her. I saw how tired she was and decided against continuing, and I'm glad that I did. I don't want to know the sort of damage that I could of done to her bones and her mental state if I had continued on as I had, with no real understanding of Join up or body language.
OP, I guess what I'm saying is that although a lot of people will tell you to go ahead and join up with the colt, my personal opinion is that you should wait and get a good foundation with this colt's mother and then with him. Being such a young one, you will with patience be able to effectively move him from the instinctive side of his brain to the side that processes thoughts- and once you have done this, you can begin to bond with him.
I could be wrong. I'm not extremely well versed in the area of Natural Horsemanship and I admit it because I am not a NH trainer or even a NH student. I am not against Natural horsemanship and I actually do use some of their methods combined with others that I have learned from more traditional trainers. But to me, unless you are well trained in the ways of NH or have someone to guide you, it is not a good idea to attempt to join up with this young horse.