Real thinking is hard and most people don't like it. A recent experiment showed that most people would administer mild electric shocks to themselves in preference to sitting alone and thinking. But reading, at least, gives you a companion.
Most of the reading we do, however, is transactional: information we need to make decisions. Little of it is discursive or challenging; it merely requires processing. So when you take discretionary time to read, what is that precious time for? I'd argue it's for thinking, not processing.
So don't spend that precious time reading about business. Spend it on something that will challenge and stretch your mind. Fiction, in particular, has been shown to enhance theory of mind--that is, the ability to see the world through the eyes of others. There's no more useful capability in any kind of work--but you won't get it reading stock charts or productivity primers.
If you don't have time or patience for fiction, try reading about leadership from a wildly different angle. My favorite piece recently was by William Deresiewicz, a former English teacher at Yale, writing about leadership and solitude. It gave me more insight into true leadership than any of the books I've read on the topic. And yes, great leaders need solitude and time to think.
Why is reading off-topic good for you? Because it forces your mind to go to different places, to access different parts of your brain. And that's the beginning of creativity: when ideas collide and spark new thoughts. Sticking to areas and information you're comfortable with may feel great, but it's only doubling down on what's familiar. For real insight, your mind needs to travel.
So here are some suggestions:
Foreign literature: If you do business in foreign countries, read their literature. I do a lot of business in Italy and have been reading the novels of Elena Ferrante, author of Days of Abandonment. They are great stories, modern, and give a lot of insight into the reality--not the myths--of Italian life.
History: Ed Conway's book, The Summit, is about the forging of the Bretton Woods agreement, which determined global economics after World War II. It is a master class in the power of personality and the genius of fierce collaboration. You have to ask: If 44 nations could solve this hard problem in just three weeks, what could you do in a business summit in just a few days?
Judgment and decision making: It's hard to imagine a harder job than Kenneth Feinberg's when he was appointed to decide how much compensation victims of 9/11 should receive from the federal government. His story of administering the fund--What Is Life Worth?--is a masterpiece of judicious empathy.
Natural sciences: Martin Nowak's SuperCooperators is a landmark work on the true science behind evolution and altruism. It's a worthy riposte to the stale idea that we all need to compete forever.
Fun fiction: My favorite book this year has been Dave Eggars's The Circle. Eric Schmidt says it isn't about Google, but he's either in denial or hasn't read it. It is a marvelously acute portrayal of a superpowerful company that believes it knows what is best for us. My tech friends love it; my non-tech friends love it; neither can decide whether to laugh or cry.
But if you don't like reading, there's always the option of that empty room and mild electric shocks.