Cumulative elevation gain

Elevation losses (i.e. periods when the person is descending) are not counted or offset against this measure.

In descending from the summit to return to their start they don't have to make any other gains in elevation (i.e. it is just continuously down), so their total CAG for the journey stays at 4,000 feet (1,200 m), which is the total of vertical distance they climbed.

Now take the case of a journey where a climber travels across several summits with more "ups-and-downs".

In descending from the first summit to return to their start they don't have to make any other gains in elevation (i.e. it is just continuously down), and their total CAG for the journey stays at 10,000 feet (3,000 m).

Cumulative elevation gain can be recorded and calculated automatically using GPS devices such as Garmin or Strava.

The seven peaks of the ' Fitz Roy traverse is one of the hardest mountain traverses with a CAG of circa 4,000 metres (13,000 ft)
No matter the shape of the hills, as long as they are each 100 vertical feet tall, then if one were to hike up each hill, the cumulative elevation gain would be 5 × (100 feet (30 m)) = 500 feet (150 m). The downhill sections are not counted.