IrisRV
Well-Known Member
Bottom line up front:What HR zone did you have to stay in?
The best way to find your safe max HR is to do exercise testing. If that's not possible, the rough calculation (220-age)*0.6 is a reasonable place to start.
My specialists have had me do the one-day CPET or AT testing (limited CPET just to AT) twice in the past 10 years or so. My results were nearly identical even though my symptoms and functionality were different, so it looks like it's a physical measure of my body's fixed level of energy production.
I was told to stay below my anaerobic threshold period. If I reached my AT, I was supposed to stop and sit immediately. Most patients find that for normal living, they need to stay about 20 bpm below the AT measured on the one-day CPET. Approaching the AT is reserved for very short-term, unavoidable exertion such as climbing stairs or pulling small children out of the path of speeding vehicles. If you're well enough to do some strength exercise, you may be okay exercising near your AT, but not over.
There is thinking that staying above your AT for more than a minute or two is what causes PEM -- not in every single case, but in physical exertion PEM. That definitely fits my experience.
The best way to determine what your own AT is is probably to do the 2-day CPET and use your AT for the second day. Next would be the cycling (not treadmill) AT test, which is a CPET that takes you right up to your AT and then stops instead of pushing to max. It is very much less likely to cause a PEM episode. It takes 5-8 minutes for many PWME.
If you can't measure your AT, you have to guess. One very rough approximation is (220-age)*0.6. You may still have to work down from there until you don't have PEM for an extended period.
Interesting bit of info -- my cardiologist ordered a dobutamine stress test for me. They had to abort it when my BP started going dangerously high (220/110). This was only halfway to where then were trying to get. What is interesting is that my otherwise normal BP started going nuts right at the (220-age)*0.6 HR level. Significant or coincidence? Who knows?