run-easy-race-hard
Here is a link to an RQ test (and discussion) I took in September, 2009. It includes some informative posts by Dr. Phil Maffetone. Make sure to ask the tester if the test measures carbon dioxide (RQ) and heart rate. The deflection point on my test coincided with the current MAF being used (128 bpm). The deflection was around 128-130 bpm. It represents a slight shift in energy systems. Below the MAF, you are using aerobic fibers, and above, you are starting to recruit anaerobic fibers.
To add to the above information by Jesse. The first two suggestions were given by Dr. Phil:
--make sure to warm-up before starting your test. If your test is anything like mine, they get right to it. What is considered warm-up is the first 6-8 minutes of the test, which most likely will bring you beyond your MAF. This can elongate the aerobic deflection point, which coincides with, or represents, your MAF. Insist on warming up.
--ask how long the test is going to be. You're better off knowing up front.
--stop when you want to. The RQ scale runs between .7 and 1.0. In my first test, the tester pushed me beyond the 1.0 to test anaerobic capacity. I went as long as possible, reaching my maximum heart rate and staying there until I couldn't go on. If you don't want to go past 1.0, then don't do it. All you really find out is an aproximate MHR, and how long you can sprint while your heart is pounding out of your chest. That may or may not be valuable to you. If not, just have the tester tell you when you reach 1.0, then stop and do a cool-down. Your Anaerobic threshold is around 1.0, that may be valuable.
Here is a locator for RQ testing facilities.
Have fun!
--Jimmy