Mark,
I do have one of those machines and have been bringing up to my doctor that my blood pressures seem high after I run. They are in the 200's. I had a stress test and my highest pressure was 220/54. They said that was OK. They also said that my VO2 level was low and that I was just out of shape. When asked how I can build up any endurance with the headaches and shortness of breath they said that to just take it slow. 3 years later I am still taking it slow but still can't build up any endurance.

One of the suggestions was that the brain autonomic system is not responding to the increased in blood flow etc. when I am running or lifting weights. They said there is nothing they can do for that. I just had some blood work done and my CO2 level was marked high but doctor said it wasn't high enough to be causing me any problems.

Thanks for your reply and I will keep checking the blood pressures and heart rates - maybe something will show up.