Heart Rate at Altitude
Heart rate increases as altitude increases. While the rate varies by individual and physical health, the body’s circulatory system is reacting to the lower pressures, which make it increasingly difficult to utilize oxygen in the bloodstream. The amount of oxygen in the air remains the same as at sea level - about 21 percent.. The heart just has to work harder because of the environmental impact. A person with heart disease has a similar difficulty breathing, especially during any exertion because the heart muscle is less effective. In both cases the person struggles to do what should be normal tasks or movement. The Mayo researchers are checking heart rates against baseline rates taken back at sea level and against various levels of exertion and altitudes.