I just finished my first walk while breathing less. My Buteyko practitioner gave me the go-ahead to incorporate reduced breathing while exercising into my daily Buteyko routine. She did this because my CP is now up to 20s in the morning (your early morning CP is apt to be the lowest of the day) which means I am strong enough to exercise without having my symptoms return. To get your CP up from 20 to 30s, exercise is almost required.
But she still would like me to go slowly and I agree with her. All winter whenever I have tried to get back to my usual exercise routine, I have had a relapse or caught a cold, or something. And when my CP was low, I would easily get out of breath. It has been frustrating. But I am in no hurry to get to yogi-master status as long as I feel I am making progress. So today, after a 5-minute warm-up of just plain walking, I held my breath (after an exhale) for 3 seconds, then breathed normally for 4 or 5 breaths, and then repeated this process. I walked for 2 miles at a moderately brisk pace. I walked with a rhythm and somewhere in the middle of the walk, I felt warmth and could breath more easily. So I switched to a 4s hold. The first few breaths after a hold were bigger, and more rapid so I waited for things to calm down before doing the next hold which usually took 4 or 5 breaths. And my mouth was closed the whole time. The idea is to feel a gentle air hunger that is not stressful.
Up until now I have been doing Single Nostril Breathing while sitting comfortably in a chair, watching a DVD, listening to an audiobook, or reading. You simply block one nostril with your finger and breathe through the other. The very first time I tried it, I overdid it and my nose got sore! So I learned to switch nostrils after about 4 minutes and do the whole routine for no longer than 20 minutes. The goal is to practice reduced breathing for 90 minutes per day total. That is the minimum required in order to see results. You can do this one while driving, too.
The easiest routine I have done is to lay flat on my back, knees bent, and just concentrate on my breathing. Sound like meditation? That's what it is. The goal is to relax my muscles, especially the breathing muscles, so that the diaphragm can do its job. This is how I discovered that my diaphragm was in spasms, my breathing irregular and way too heavy for someone lying on their back. I put one hand on my chest (to make sure it didn't move) and one hand on my upper abdomen (to make sure it did). I soon found that neither was moving and my breath had become extremely light and slow. That's exactly what my practitioner wanted.
Why reduced breathing? Somehow I have gotten into the habit of breathing more than I need to. The breathing center in the brain is sensitive to the amount of CO2 both in our brain and in our blood and mine has gotten set at a lower amount than is normal. If I really breathe too heavily, I will start to wheeze because mucous is collecting in my lungs to stop me from losing more of the precious CO2. If I hold my breath, the level of CO2 rises. So what I am doing with my reduced breathing exercises is to try to reset the level of CO2 that my breathing center will accept as normal. I want it to be higher. So I have to coax it by breathing less for a substantial amount of time every day.
Things that cause over-breathing include stress (the number one problem for most of us), over-eating, talking too much (hey, it pays to be the quiet one), breathing through the mouth and chest breathing, heat, sleeping on the back, lack of exercise, and the mistaken belief that it is good to take big, deep breaths. Things that can reduce breathing include breathing through the nose, breathing from the diaphragm, eating less, keeping cool, dressing less, getting outdoors more, going barefoot (that fits in with being Paleo), and sleeping on the left side or tummy.
I'll keep you posted on my progress.