The context of the following conversation is Kai has a practises every single day, which are really hard and fast paced.:
Kai says I have practice again today..
The friend responds You sound disappointed..
Kai responds I am a little bit.  They just wear me out so much..
The friend responds Well they say, no pain no gain..
Kai responds I know this is true which is why I am not giving up..
The friend responds Good for you!.