I suppose some people think that the FEV1 is a measure of "lung efficiency", but it's really not. It's simply a measure of how much you can blow out compared to someone with no lung disease. It actually measures the degree of obstruction (chronic obstructive pulmonary disease). People with the same FEV1 have vastly different capabilities. I can do lots of thing, but my mirror image barely can leave her home.

By exercising and getting stronger you can increase the efficiency of the lung function you do have, but you need to measure what you can do today after all that exercise versus what you could do before you started the exercise program. That's as good a measure of efficiency as you'll get. Check with your doc, but I don't think there's any good measure of lung efficiency. Let me know if he tells you there is; I'd like to know!

RC, the oximeter measures the amount of O2 in the blood; it doesn't measure breathing at all. The reason you use your oximeter is to be sure that you are staying adequately oxygenated. If your sats dip below 88, you need to either turn your O2 up, or get a prescription for supplementary O2. It has nothing to do with lung efficiency at all, but it is a very important concept to know. Anything under 88 means you're not doing well and need more O2. In the 90s, generally you're fine.

Yes they do work. I check my breathing and heart rate all the time. If my breathing gets a little low I use breathing techniques to get it back up. No they don’t help your lungs but they do tell you when your oxygen level in your blood is low and for you to take action to get it back up to where it should be. Sometimes my drops down to 88/89 and get it back up in the 94/95 in a few seconds by breathing techniques I have learned through trail and error. It certainly measures both breathing rate(oxygen level ) & heart in easy to understand numbers. I exercise every other day by using 5 lb weights and walking and make sure its for 30 minutes or more, I have Pulmonary Fibrosis and not COPD.

Excellent. Very helpful to understand. The take-away is that if someone is on Oxygen prescription, then pulse oximeter is the way to go. If someone is still not on O2 medication, then it is only marginally helpful. Other medications, such as basic exercise, good food habits etc. are more important. Did I get it right?

Pulse oximeters show your oxygen saturation and your pulse rate. By breathing efficiency do you mean how much oxygen is in your body? If so then the pulse oximeter will do that. It is only a tool to show how much oxygen is in your body with or without using oxygen.

I took a picture of my oximeter in use. The picture on the left is me using oxygen at rest. 98% saturation with a pulse rate of 94. The picture on the left is me at rest without oxygen. 83% oxygen saturation level with a pulse rate of 101. It doesn't matter if you are on oxygen or not to use a pulse oximeter. It is only a tool showing how much oxygen you have at the time you use it.

An oximeter tells you if your O2 sats are where they should be. It tells you nothing at all about the efficiency of your lungs. To my knowledge there's no way to measure that specifically. I can tell you that if you exercise daily and push yourself a bit all the time, you will find that you will be able to do a lot more with a lot less effort and less O2: that's efficiency. So one way to measure your efficiency is to keep track of how much more you can do today than last week or three weeks ago. It's also another way to know if you're heading for an exacerbation: when you can't do today what you did in the gym yesterday or the day before, you may be headed for trouble.