As someone who wrote thousands of programs in my lifetime, I'd advise you to take longer breaks between reads to allow the material to sink in. You'll find your comprehension actually goes up. And that makes it more efficient in the end. You'll become a better, smarter programmer.

When you work out, focus on the workout, enjoy it, give your mind a rest and put your body to work instead. If your body is healthy, the brain functions better, believe it or not.