heart rates

Im a 39 year old female, Im 5'1. I suffer from anxiety, my resting heart rate is about 90. Ive recently started going to the gym again about 3 times a week. When Im speed walking on the treadmill for 30 minutes, my heart rate gets up around 165, then I do some weight lifting. How high should my heart rate get before I should stop cause I might be doing more harm than good?

[gymdandee]

For vigorous exercise, aim for a target heart rate of 70 to 85 percent of your maximum heart rate. Your MHR (roughly calculated as 220 minus your age) is the upper limit of what your cardiovascular system can handle during physical activity.
your age 39 deducted from 220 = 181 so 70-85% of 181= 127-154 as your target heart rate

[shortstuff71]

Thank you sooo much! :) So I should only, safely, let my heart rate get up to 154 max til I get back into better shape or indefinitely? I really appreciate the help!

[gymdandee]

If you can have a conversation with your HR at 154 that's OK! If you can't then adjust your HR till you can have that conversation!  As you improve raise your HR. As you get older recalculate your HR.

[Dr Arora]

Hi, your target heart rate is something around 140 to 150 which means this is the desired range of heart rate which you should achieve during aerobic exercise is to attain maximum benefit. But that does not mean that you cannot reach a heartrate more than this. You can slowly increase the momentum and increase the workload till you are comfortable. This is just a rough idea of the indication that you are exercising to a good extent. Focus more on spending time during aerobic exercise rather than looking at heartrate. Cheers