I have a 12 y/o OTTB who I previously evented with when I was in highschool and college. I am back home now and he is being boarded at a friend’s farm nearby. We aren’t currently competing or taking lessons. We have access to many miles of trails, a large field, and a dressage arena. Until fall comes, we can’t do a lot of trail riding due to all of the flies that make him miserable the entire ride 
I would love some ideas of fun arena exercises to do so we don’t get bored just going around in circles. We have a couple cavalettis and ground poles, so they can be included in the exercises. He has always had issues with being tense through his back so any exercises that could help him relax would be great. I didn’t see any recent topics that were similar so please direct me to them if y’all know of any. Thanks 
Have you checked out pinterest? There is a plethora of ideas there and they have visuals which is very helpful. I’ll pm you where I have all mine saved and then just click through them and you’ll see more suggestions and before you know it you’ve wasted hours looking up all sorts of different exercises… or maybe that is just me.
Some ideas for you:
9 ft canter poles, in an arc (for turning in a collected canter)
changing lead over a pole/caveletti
trot poles of various widths - a set on one side of the arena for a lengthened trot and a set on the other side for collected
working on lateral movement, turn on the forehand, turn on the haunches
work on transitions at a letter, rather than in a corner or between letters
work on picking up the correct lead NOT on the rail
These are some things I do with my students if they are taking a lesson when we’re not jumping, hope that helps!
I use this book extensively when we are stuck indoors for the winter 
https://www.amazon.com/Dressage-Exercises-Horse-Rider-Read/dp/1580175953
Just want to add that you may keep an eye out for a Rambo FlyRider sheet. I bought mine on clearance online for $35. It has a mesh neck piece and a quarter sheet piece that can be used together or separately. It makes a HUGE difference when I need to hack during bug season. There is no fly spray in the world that keeps hordes of deerflies, greenhead horse flies, and the big bombers away. I’ve been swarmed while trotting, you have to flat-out gallop to get away from them, and whenever you walk to rest they catch back up…it’s utterly miserable for the poor horse. However, using the FlyRider pieces lets me hack peacefully during bug season. Add a fly mask, slather the belly in SWAT, and have a good ride.
I wouldn’t do much trot/canter work in the outfit, as horses will get hot and foamy sweaty in humid weather. But to enjoy a walk on the trail away from the ring, I love it.
I will definitely look into one! The other people at my barn get away with just using fly spray and an ear bonnet, but for some reason the flies are always attacking my horse worse than the others, I guess he’s just a thin skinned thoroughbred :no:
There is also an app called Equisense that I downloaded for free. It has some interesting stuff, both with and without poles.
Just downloaded and it looks pretty cool! Thanks for the suggestion
