Even if you have cast-iron willpower, the mere fact that the Internet is lying in wait on your computer takes a toll on your work performance. The very act of resisting temptations eats up concentration and leaves you mentally depleted.
Manage Your Day-to-Day: Build Your Routine, Find Your Focus, and Sharpen Your Creative Mind (The 99U Book Series) by Jocelyn K. Glei, 99U