Physiologically, what you’re doing is resetting your body’s set point for stress. Our fight-or-flight mechanism is supposed to kick in when we are running from a lion to save our lives, not when our brussels sprouts are slightly undercooked, and not when we are worried that our house isn’t as big as that of a former classmate who we just reconnected with on Facebook. The easiest way to convince your body that sitting in traffic is not worthy of a stress-induced freakout is by showing your body what real stress feels like, in the controlled setting of your daily workout.
