Exercise does all kinds of stuff to your body when you first start out, and beginning a running routine is no different. Wired decided to take a close look at all the wonderful, horrible things that happen to your body when you start running for the first time, and get the science behind it.


Speaking with Steven Magness, the author of The Science of Running, Wired got to the bottom of a few of the more uncomfortable truths of starting up a running routine. Here are a couple of the lesser known oddities your body goes through:

The first came from my skin. I hadn't made it to the end of my block before my chest started itching. It was like someone had stuffed my shirt full of wood chips. What's actually happening, says Magness, is blood flowing into tiny unused capillaries in my skin. In non-runners like me, these capillaries are dormant. When they get flooded with blood irregularly, they swell. This irritates nearby nerve endings, which sends itchy sensations to the brain...

[M]y tummy started burbling before I was close to the first sloping street. I ended up speed walking the last few blocks home. "This is pretty common," Magness graciously told me. Many runners also get gassy because their bodies are breaking down energy (in the form of sugary carbohydrates, solid proteins, or rich fats), causing muscles cells to release gas. A lot of this gas ends up not making it to the lungs, where it can be expired without embarrassment. As Magness tactfully put it: "Gas gets stuck in places where it shouldn't be, and you gotta get it out some way." Also, he says, the mechanical jarring of running helps along the digestion process.


Of course, you can also expect side stitches, burning muscles, and plenty other creaks and groans from your body as you get started. The good news is that it's all probably normal, so while it's a bit uncomfortable at first, know that it goes away over time.

What's Up With That: Why Running Hurts Every part of Your Body | Wired

Photo by Kevin Dooley.