This should be done on a treadmill, but you can use a bike trainer or go to a track or up a hill to acomplish the same thing.

Start with a thorough warm-up of about 20 min in an aerobic heart rate zone. The, in two minute stages, gradually increase the intensity of the exercise, evenly, either by increasing speed or incline or resistance.

Treadmil: Start at 0% and 1.5 mph. Stage two is 1.7mph and 10%, 3 is 2.5mph and 12%, 4 is 3.4mph and 14%, 5 is 4.2mph and 16%, 6 is 5mph and 18%, and the last stage is 5.5mph and 20%. You won't get that far, but you'll get a max HR is you do it right and are extrememly motivated. That is the key to any test, motivation.

You can do the same thing with a bike trainer by dropping a gear and maintaining cadence, then when you bottom out the gearing incresing cadence 3-5rpm also in 2min stages. On the track its a little harder, but the principle is the same. Just go harder incrementally in the same stages...until you can't go any harder.

Hope this helps...be careful and make sure your doc says it's ok to do this. We don't do GXTs for alot of people who you would think are healthy.

tommy