Difference in Total Ascent and Total Descent

You may notice a difference in Total Ascent and Total Descent on activities that follow the same path out and back. If you plotted a route along the same path on a map, you would see equal Total Ascent and Total Descent. However, when the route is followed in real life, with sensors determining your elevation along and environmental factors coming into play, you will find that Total Ascent and Total Descent are not always equal. 

As you increase in altitude the air pressure decreases, but there are other factors that can change barometric pressure and cause inaccurate elevation readings. Slight changes in weather can raise or drop barometric pressure and make your watch or handheld report higher or lower elevations. This, and other factors, lead to the difference in Total Ascent and Total Descent. 

For more information on factors that can interfere with accurate readings, see Related.

Note: Garmin's outdoor devices are designed as recreational GPS devices, as an aid to navigation. They should not be used for any activity requiring precise measurements, such as surveying or weather prediction.