Try to run 200 meters with a nose clip and breathing through a straw. At the end when you are dizzy and exhausted, you will know what it’s like to have 20-30% lung power! You are out of breath like they were in the video pretty much all of the time. Exercising or even just walking up three flights of stairs is basically torture. Not to mention having to cough up thick mucus and wheezing like an 80 year old life-long smoker.
Thank God I am in the 80-90% range now. No more coughing, no more vest, no more nebulizers, no more oxygen, no more CPAP, no more lung infections, and no more PICC lines!