Runners love advice. Reading it, heeding it, sharing it. But in the middle of a tough workout, you forget how exactly a lactate-threshold run affects mitochondria. What sticks instead is short, pithy, maybe reflective, often funny. In the old days, you might’ve called it an aphorism. Today, it’s a tweet. So we asked our Twitter followers, what sticks with you? This “fast advice” comes from experts, coaches, and readers. Perfect for RT. - by Dimity McDowell