Whats is a dangerous heart rate while doin cardio ?

Varies: There is no specific dangerous heart rate during exercise. How fast your heart beats with exercise depends on a number of factors, especially your conditioning. If you are healthy, a heart reate in the 170's or even higher may be ok and tolerated. Now if you have a problem such as coronary disease, the safe heart rate would depend on an assessment by your doctor. A stress test is commonly done.

Depends on your age: "NormaL" Maximun heart rate is 220 minus your age (220- 22 = 198) That is max. When under supervision (for stress test as an example), it is advisable to get at least to 85% of that heart rate (198 x 0.85 = 168bpm) However: for sustained HR during exercise, you will get benefit from 60-75% of max rate (120- 150 bpm) I hope I did not confuse you with the answer :) Get Started soon. It IS important