What is the meaning of 10% gradient on treadmill?

Transcript of the video: A question that is often asked is, what is the meaning of 10% gradient in a treadmill test? Usually, in the first stage of Bruce protocol, of treadmill test, there is a 10% gradient in stage 1. That means, if the treadmill length is 150 centimeters, the front end is elevated, about 15 cm from the ground, so that this produces a slope. So 15 cm elevation for a 150 cm treadmill will give a 10% gradient. This is what happens in stage 1 of standard Bruce protocol. In modified Bruce protocol, there is no gradient in stage 1, so that the treadmill will be horizontal. In stage 2, 5% gradient is given and stage 3, there is 10% gradient. So stage 3 of modified Bruce protocol will correspond to stage 1 of standard Bruce protocol. From that onwards, every stage in either standard Bruce protocol or modified Bruce protocol gets an increment in gradient of 2%. So stage 2 in standard Bruce protocol will have 12% gradient. The importance of gradient is that, as the gradient increases, the person is walking uphill. So, for the same level of speed, a gradient of zero and gradient of 10% is compared, this obviously will have more exertion. That is why, in modified Bruce protocol, which is meant for less fit persons, the first stage is with zero percent gradient. Earlier, this was even called as stage 0, and second stage of modified Bruce protocol was called as stage 1/2, and the current stage 3 of modified Bruce protocol was called as stage 1. But then the confusion was there, and the terminology has been changed so that stage 3 of modified Bruce protocol will be now equivalent to stage 1 of standard Bruce protocol. So this is the concept of gradient, meant to give increased exertion at the same treadmill speed.