Thank you for your question! I understand your concern, about heart beating feelings; but I want to assure you that when discussing about cardiovascular response to physical efforts there are not any rigid limits ore ranges; heart rate varies according to your age, weight, your body physical preconditioning (that is the presence of your prior history of physical activity); probable medications that you could take; the physical endurance that you are imposed to,etc, and of course your actual health status. But as long as that sensation (palpitations) doesn't interfere with your activity or cause any special disturbances to you, there is nothing to worry about.
If palpitations will be an unpleasant and persistent even at rest then you have to visit your doctor (GP) to perform a routine check up (physical exam and some blood tests) and if necessary an ambulatory ECG monitoring to clarify your rhythm.
Hope to have been helpful to you. Greetings from Dr. Iliri