Weight training provides an immediate, temporary preview of progress, unlike endurance exercise.

“When you run and you're gasping for air, you aren't experiencing what it's like to be faster than you are that day. But when you weight train, you get an aesthetic picture into how your functionality and aesthetic will change. It disappears a few hours later-- as the so-called "pump" subsides, but it's a very interesting form of exercise in that way. It's almost as if you go in to learn a language and during the process of learning, for brief moments, you're actually fluent, and then it gets taken away. So it puts the dopamine carrot out in front of you.”