One, I think that might be a good question for your doctor.
It certainly seems logical that the Adderall would speed up your heart rate and make standard HR tables pretty useless in your case.
Canfield, a couple of things ... first of all, I don't think you need to be concerned at all about your heart rate. When people first start exercising (I don't know if you're fairly new at this or not
), they often have very high heart rates because their hearts - which are muscles - are so deconditioned. As you become more cardiovascularly fit, your heart rate tends to drop, both resting and upon exertion. So you may see your heart rate drop over the next few months, even if you're working as hard or harder than you are now. It's a good thing!
Second, that formula is just an estimate of what your max heart rate is. We wouldn't know for sure unless we took you to a lab and hooked you up to all sorts of equipment measuring your O2 input and output while you exercised - not real practical for most of us!
You're really not going to hurt anything even if you exercise at or above your theoretical max (I do it sometimes). Target heart rates are really designed to get people to work harder, not to back off.
Third, I'm going to have to disagree with the sticky's formula for finding a target heart rate. 70% of max is low intensity exercise - I think most people would benefit from working out at a higher intensity, at least part of the time. Here's how I was taught to classify heart rate:
65 - 75% max = low intensity exercise
75 - 85% max = moderate intensity
85 - 90% max = high intensity
The higher the intensity, the more calories you'll burn - a good thing! My recommendation to clients is to do most of their cardio in the moderate intensity range, with bursts of high intensity intervals thrown in periodically.
Let's see, I'm guessing that you're 24, right? If that's the case, your 165 is right around 85% of your max heart rate and that's a great place to be. Throw in some high intensity intervals and you'll do fantastically well!