Is it normal to notice increase in heart rate when bending over whilst sitting down?

Yes, this is a common occurence. While sitting down and bending over, your body is in a state of decreased circulation known as orthostatic hypotension. This position makes it harder for your body to pump blood, especially to your brain. An important safety practice is to change position slowly to allow your body time to adjust. If you experience dizziness, blurred vision, or fainting, it is best to stand up slowly. If these symptoms persist, seek medical attention.