high pulse

i am 39 yrs old male and exercise almost daily. when i am in the gym i am great. but some time i am setting down and without any exercise my pulse go up rapidly. i need to know what that can be.

Difficult one to even speculate about. It's worth noting that the very act of taking your pulse can produce enough stress when relaxed to increase your pulse rate! When your body is under more stress, such as with exercise, the heart rate is being driven by the hormones more directly. High pulse rate is called tachycardia (as opposed to too low pulse called bradycardia or brachycardia)

This is one that your doctor should have a look at ... possibly an EKG test might reveal something unusual in the electrical conduction through your heart that's causing less control of your heart rate. It may take a heart rate monitor.