In fact, this is a fallback option to deal with any kind of mental stress, as well as the answer to the boredom caused by desk jobs. But I wouldn't discard reading altogether. It is an all-encompassing thing, and you just need to find what actually interests you, deep down inside, and then read into it to the hilt. In this fashion, you won't be so much relaxed as motivated (more of a roller coaster type of experience) because you will get something else from this activity other than just instant gratification and entertainment (read, it will be more rewarding in the long run). That's what hobbies are for unless your job is that hobby, but then you wouldn't ask obviously (this is an ideal situation but rarely the case in real life, though)
I like that you are still insisting on reading as a way of relaxation
Well, I wouldn't call it so much a means of obtaining relaxation as satisfaction
In this regard, reading is like money. With money, you can spend it uselessly (like on drugs, whores, partying, or even reckless gambling, while we are at it), and you will most certainly regret this type of spending later. On the other hand, you can spend the money with some useful long-term purpose in mind (e.g. buy a few bitcoins now and then), something which relates to you and your interests as you see and feel them deep in your heart
Reading for its own sake is meaningless, it is what you get out of it that matters and counts. It is only a tool which gives you a key to new opportunities. Discovering these new opportunities, or rather concrete ways to actually work them as you read into other people experiences, is what makes reading so fun and enjoyable. It is like you are living not just your own life but the lives of other people, gaining from their mistakes and successes alike