Table 1. Examples of Treadmill Testing Protocols for Peripheral Arterial Disease

Time, min Speed, mph Hiatt16 Grade Stage Gardner22 Grade Stage Standard15 Grade

1 2.0 0% 0% 12.0%
2 2.0 0% 0% 1 12.0%
3 2.0 0% 1 2.0% 12.0%
4 2.0 3.5% 2.0% 2 12.0%
5 2.0 3.5% 4.0% 12.0%
6 2.0 3.5% 2 4.0% 3 12.0%
7 2.0 7.0% 6.0% 12.0%
8 2.0 7.0% 6.0% 4 12.0%
9 2.0 7.0% 3 8.0% 12.0%
10 2.0 10.5% 8.0% 5 12.0%
11 2.0 10.5% 10.0% 12.0%
12 2.0 10.5% 4 10.0% 6 12.0%
13 2.0 14.0% 12.0% 12.0%
14 2.0 14.0% 12.0% 7 12.0%
15 2.0 14.0% 5 14.0% 12.0%
16 2.0 17.5% 14.0% 8 12.0%

The Hiatt and Gardner graded treadmill protocols have been validated in the peripheral arterial disease population. The speed is held constant at 2.0 mph, with an increase in grade of 3.5% every 3 minutes (Hiatt) or 2.0% every 2 minutes (Gardner). The constant-load "standard" treadmill protocol is performed at either 1.5 or 2.0 mph, at a fixed grade of 12%.