<span>It is volcanic mud-flow. These mud-flows also known as Lahars are made up of debris and mud. The debris typically consists of rock fragments. The size and speed of the mud-flow can increase as it rolls downstream and incorporate more material as spreads such as rocks, buildings and soil.</span>
I think the answer to this is To measure your muscle mass.
C. Decrease the intensity and inline of the treadmill.
Since Cecelia's heart rate, 187 beats per minute, is already above her target heart rate zone 138 to 175 beats per minute, she should decrease the intensity and inline of the treadmill to lower her heart rate.
Increasing intensity and incline will further hasten her heart rate. The duration of the treadmill timer does not impact Cecelia's heart rate.