Could you please tell me the proper way to measure recovery heart rate? does duration of exercise matter? i was hoping to do it after 30mins of cardio.

Check pulse: Immediately after exercise and again 1 minute later. Normal heart rate recovery is defined as a decrease in your pulse of 15 to 25 beats per minute. Abnormal heart rate recovery is usually defined as a decrease of 12 or fewer beats per minute. There are several different methods, but this is a good rule of thumb. Checking following 15 min of exercise is good enough, so 30 min is ok too.

Various ways: Count your pulse immediately after that exercise for 10 seconds and multiply by 6 for the end of exercise heart rate in beats per minute . Measure again in 1 minute and the rate should be at least 12 beats per minute less. In 2 minutes it should be at least 22 beats per minute less. The faster the heart rate goes down the better. Overheating and dehydration may keep pulse elevated.