If you have a horse that is fairly stubborn riding can feel like an absolute chore. There are days that you just won't have the energy to put up with struggle. There will be days that you will question yourself and ask 'what am I doing wrong?' Well the simple answer is that you don't have the right training system for your horse.
Horses are quick learners. Even the ones that don't have good work ethic will learn super fast. And most likely they are learning very quickly how to get out of doing work.
With a stubborn horse you have to be more stubborn than them in order to get anywhere with them. Now when I say stubborn this does not mean getting violent with them, this just means that you can't give up asking them once you start. No matter how tired you get! So for example if you ask your horse to go - click, squeeze, kick. And your horse does not respond and you stop asking even for like a second, your horse has learnt that you won't follow through with what you ask of them.
This gives your horse more motivation to ignore you. They know that if you ask, you will give up.
You have to show them that you won't give up. You have to keep going with your aids until you get a response. Then release the pressure INSTANTLY!
Now you have a pressure release training system.
This does take practise to get right. Keep at it! You will see improvement with them ina short amount of time.