2 mph 16% incline
There is also a Modified Bruce protocol, which starts at a lower workload than the standard test, and is typically used for
elderly or sedentary patients. The fist two
stages of the Modified Bruce Test are performed at a 1.7 mph and 0% grade and 1.7 mph and 5% grade, and the third stage corresponds to the first stage of the Standard Bruce Test protocol as listed above.
The Bruce Protocol is described in more detail at
http://www.topendsports.com/testing/tests/bruce.