Stretching Your Lungs

Last night I went on a run with 2 guy friends from one of the companies I work for. They are both very experienced runners, so I knew I was in for a difficult run. We met at Yuba and agreed on 5 miles (not "to the drinking fountain and back" which we all know isn't actually 2.5 miles according to Garmin, they wanted to run 5 REAL miles). They were particular about the distance, and they were FAST.

We took off and after a few minutes I felt my heart wanting to explode - already! My trusty Garmin told me we were running at a 7:50 pace. No thank you. I slightly slowed down, silently encouraging them to do the same.

We ended up running the 5 miles in 44 minutes which is a first for me. I've never kept up an 8 something minute pace for 5 miles. 2 miles? Yes. 5? No.

I walked back to my car and drove home already feeling exhausted. By the time I got home, my chest hurt, my lungs hurt, my head hurt, blah blah blah...everything hurt. Later that night I mentioned that my lungs hurt to Brook (thinking it was just my weak lungs) and he said, "That's great! They're stretching."

"What? They're what?" I thought he was making junk up. I thought my lungs only stretched when I practiced streching them by doing vocal exercises and purposefully would hold my breath or would hold my breath under water and work on filling up my lungs, etc.

I understand the whole speed work outs, working on being able to endure more hills, taking short rest breaks to keep your body working hard, which then by default helps build your lung strength, but I had NEVER put the two together about purposefully stretching my lungs. And then I thought, I don't ever recall even having a discussion with anyone regarding this topic. Why don't runners work on breathing exercises to help expand their lung capacity? Like I mentioned, many types of workouts help increase your lung capacity, but that's not necessarily the only goal - it's to increase your fast twitch muscles, your lactic acid threashold, your heart rate, and many other factors.

Why don't runners dedicate exercises JUST to stretching your lungs? Or, why had I never heard of this if they do?

I googled "how to stretch lungs" and came up with a ton of clinical studies where scientists tested lung stretching techniques on mice and found that voila! They worked.

After searching through the clinical data, I found some informal websites like this http://everything2.com/user/JosieWales/writeups/Stretching+your+lungs

and also a YouTube video of Michael Phelps teaching breathing exercises.

Essentially, I feel very out of the loop and feel like especially for someone like me who has poopy lungs, I could very much benefit from sitting on my couch and doing lung stretching exercises in my down time.

Have any of you tried this? Or, read articles about this, heard about this, have advice?