Dear (имя), thank you for your recent letter.
I think just like you, I would prefer go for a walk rather than spending time on fitness center, or simply staying at home. I like to read newspapers, magazines, watch TV and surf on the internet in my free lesson time. My hobby is wrestling, I like it because it's interesting fights, but no one gets damaged from it, just show.
So, it's all for now.
All the best,