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Charles Darwin only worked about four hours a day and still was able to write "probably the single most famous book in the history of science," writes Alex Soojung-Kim Pang in the journal Nautilus. According to the Pang's research, Ernest Hemingway worked six hours a day, Gabriel Garcia Marquez hewed closer to five, Stephen King says anything over four is "strenuous," and Alice Munro, who won the 2013 Nobel Prize in Literature, sticks to three.

These creators aren't lazy: They're efficient. And now there's a wealth of evidence to suggest that a few hours of intensive practice a day, as opposed to a couple four-hour blocks sandwiching a brief lunch break, is optimal for achieving success.

Basically, science shows, you can get more done in less time. And, by working too much, you might be holding yourself back.

But before you reduce your hours, you have to know how to use your hours the right way.

Don't multitask

Distractions abound, but to work in an efficient, focused way, you need to ignore them. In the Age of Smartphones and quick dopamine hits, you're probably bad at this. A 2015 study pegged the average attention span at eight seconds. That's shorter than a goldfish's.

The consensus among experts is that trying to do multiple things at once limits you.

Daniel Weissman, a neuroscientist at the University of Michigan, ran a study in which subjects sat inside of MRI scanners and had to decide which of two differently colored numbers on a screen was larger. Weismann found that before subjects provided an answer, they paused because they had to mentally round up the information about one color's task and push aside the other's.

"Even simple tasks can overwhelm the brain when we try to do several at once," he concluded.

In another study, just listening to background music made subjects' performance worse on a memory task.

Some scientists don't even think multitasking is real. When you think you're doing two things at once, they claim that in actuality you're just jumping between the two, which is mentally exhausting.

In any case, the science agrees that focusing on a single task is best.