Tina Sederholm answers:
To have any chance of calming your horse down, stop racing with your friends! Although it’s fun, it is encouraging him to be hyped-up around other horses. This will carry over into your showjumping when he needs to be calm, so that he does not rush and make any mistakes.
I would suggest that you take your horse back to doing some gridwork (or gymnastic jumping) at home, in order to get him thinking in front of a fence again. You can find details of simple gridwork in exercises in my book, ‘Unlock your Riding Talent’, or in almost any book on showjumping.
You sound quite an excitable person, so if you are going to get your horse to calm down, I think that you need to calm down, too! One tried-and-tested way to do this while riding is to stop talking and breathe deeply into your belly for a few breaths. Then when you start to work your horse, do it in a calm, organised and logical way. Your horse will soon start to settle if he feels that you are settled, too.
I also recommend that if he rushes at a fence, you pull him up afterwards on a straight line as soon as you can. Then walk him a bit and if it is suitable, jump the fence back in the opposite direction. Bring him back to walk again, then choose another fence and do the same.
This way, you break up the momentum and start teaching him to listen to you between fences. This will obviously take time and patience, so only embark on it if you are serious about changing your horse’s way of going. If you are more in love with the racy part of him, then stick to small courses instead.