A normal heart rate, or pulse, at rest is 60 to 100 beats per minute, according to the American Heart Association. People who are physically fit may have lower heart rates, while people who are very overweight or in poor health may experience higher heart rates, even when seated.
Several factors can affect heart rate, notes the American Heart Association. The air temperature and humidity can cause the pulse rate to increase, as can emotions and stress. Standing up can cause an elevation in heart rate for a few minutes. Taking more thyroid medication than needed can also cause a rise in pulse rate.