Target Heart Rates

What is your target heart rate for your age? Here is a Heart Rate Calculator at the Mayo Clinic.
According to this calculator, for my age of 57, I should be at 114-139.

This is a brief synopsis from the Mayor Clinic:

For vigorous exercise, aim for a target heart rate of 70 to 85 percent of your maximum heart rate (MHR). Your MHR (roughly calculated as 220 minus your age) is the upper limit of what your cardiovascular system can handle during physical activity.

These numbers are estimates that provide an average value. Many people have a higher or lower MHR, sometimes by as much as 15 to 20 beats per minute. Disagreement exists on how to most accurately estimate your MHR and what percentage range to target.

If you're looking for more than an estimate, consider discussing your target range with an exercise physiologist or personal trainer.

Note: Several types of medications can lower your maximum heart rate and, therefore, lower your target heart rate zone. Beta blockers, most anti-arrhythmic medications, some calcium blockers and digoxin are among the most common. In some people, H-2 blockers prescribed for acid reflux also reduce maximum heart rate. If you're taking any of these medications, ask your doctor if you need to use a lower target heart rate.

Notice the last paragraph in red! I am on beta blockers & medicine for acid reflux - Aciphex. Therefore, should I be pushing my heart rate to the suggested 114-139 range suggested in the calculation for my age? My PVC's are occurring at the 105-110 range. Should I be there in exercise? Another question for my nurses & doctors!!!

Today's readings were 113/75 for Blood Pressure and 65 for resting heart rate.