Spirit CT850 Owner's Manual page 26

Gerkin
The Gerkin protocol, also known as the fireman's protocol, and is a submax Vo2 (volume of oxygen)
test. The test will increase speed and elevation alternately until you reach 85% of your Max heart rate.
The time it takes for you to reach 85% determines the test score (Vo2 max) as shown in the chart
below.
Stage Time
1 0 to 1:00
2.1 1:00
2.2 1:30
2.3 1:45
2.4 2:00
3.1 2:15
3.2 2:30
3.3 2:45
3.4 3:00
4.1 3:15
4.2 3:30
4.3 3:45
4.4 4:00
5.1 4:15
5.2 4:30
5.3 4:45
5.4 5:00
6.1 5:15
6.2 5:30
6.3 5:45
24
6.4 6:00
7.1 6:15
7.2 6:30
7.3 6:45
Speed Grade VO2 Max
4.5mph 0% 31.15
4.5mph 2% 32.55
4.5mph 2% 33.6
4.5mph 2% 34.65
5.0mph 2% 35.35
5.0mph 2% 37.45
5.0mph 2% 39.55
5.0mph 2% 41.3
5.0mph 4% 43.4
5.0mph 4% 44.1
5.0mph 4% 45.15
5.0mph 4% 46.2
5.5mph 4% 46.5
5.5mph 4% 48.6
5.5mph 4% 50
5.5mph 4% 51.4
5.5mph 6% 52.8
5.5mph 6% 53.9
5.5mph 6% 54.9
5.5mph 6% 56
6.0mph 6% 57
6.0mph 6% 57.7
6.0mph 6% 58.8
6.0mph 6% 60.2
3.4 3:00 5.0mph
4.1 3:15 5.0mph
4.2 3:30 5.0mph
4.3 3:45 5.0mph
4.4 4:00 5.5mph
5.1 4:15 5.5mph
5.2 4:30 5.5mph
5.3 4:45 5.5mph
5.4 5:00 5.5mph
6.1 5:15 5.5mph
6.2 5:30 5.5mph
6.3 5:45 5.5mph
6.4 6:00 6.0mph
7.1 6:15 6.0mph
7.2 6:30 6.0mph
7.3 6:45 6.0mph
7.4 7:00 6.0mph
8.1 7:15 6.0mph
8.2 7:30 6.0mph
8.3 7:45 6.0mph
8.4 8:00 6.5mph
9.1 8:15 6.5mph
9.2 8:30 6.5mph
9.3 8:45 6.5mph
9.4 9:00 6.5mph
10.1 9:15 6.5mph
10.2 9:30 6.5mph
10.3 9:45 6.5mph
10.4 10:00 7.0mph
11.1 10:15 7.0mph
11.2 10:30 7.0mph
11.3 10:45 7.0mph
11.4 11:00 7.0mph
4% 43.4
4% 44.1
4% 45.15
4% 46.2
4% 46.5
4% 48.6
4% 50
4% 51.4
6% 52.8
6% 53.9
6% 54.9
6% 56
6% 57
6% 57.7
6% 58.8
6% 60.2
8% 61.2
8% 62.3
8% 63.3
8% 64
8% 65
8% 66.5
8% 68.2
8% 69
10% 70.7
10% 72.1
10% 73.1
10% 73.8
10% 74.9
10% 76.3
10% 77.7
10% 79.1
10% 80