Scientists have discovered why running makes you happy

The Chicago Tribune reports:

If you're a big runner like me you know what I'm talking about when I describe that euphoric feeling you get in the middle of your workout — when your feet feel like they are floating over the ground and you can almost hear the air dancing past you.

It turns out it's not all in your mind.

Scientists at the University of Montreal have discovered that the hormone leptin — nicknamed the "satiety hormone" — may be at play.

The primary purpose of leptin is in regulating energy stores. It signals to the body when it has enough fuel and energy, and in previous studies researchers have found that levels of leptin appear to fluctuate in people suffering from obesity, starvation, sleep deprivation and emotional stress. When you're in motion, your leptin levels may fall, and the researchers said this could "send a hunger signal to the brain's pleasure center to generate the rewarding effects of running."

No word yet on this story from health and fitness expert Senator Barbara Mikulski.