I am wondering how many of you have gone to an exercise physiology lab and gotten a measurement of your VO2 Max? The test measures how much oxygen you breath in and how much CO2 you breath out as they steadily increase your workload during exercise. The point at which there is a surge of CO2 and the CO2 exhaled exceeds O2 going in you have reached your VO2 Max. Basically this is a measurement of the maximum amount of oxygen you can utilize during exercise. I compared my number against a population study of VO2Max numbers, and I was the single lowest data point in a population study of about 200 people! It put real tangible proof to my claims of fatigue and it's an interesting conversation piece to shove in the face of a physician who is hinting you might be making it all up. I recommend you all get this test done, not only to quantify your level of exercise intolerance, but also to have a "get out of jail free" report to shove in the face of the next moron who says nothing is wrong with you. In addition to being curious what kinds of VO2Max numbers other people who get post exertional malaise (PEM) are getting, does anyone know of a good population study on CFS sufferers that shows their typical measured VO2Max?