Before trying the 12-3-30 workout, I had been rowing 10,000 meters regularly (which takes about an hour). I didn't want to lose my rowing endurance completely, so I cut my rowing workout in half (to about 5,000 meters). I did my rowing before 12-3-30, which helped warm up my lower back, glutes, and hamstrings for the steep 12 percent incline. After getting off the rower, I did a couple minutes of stretching before warming up on the actual treadmill.
I started with no incline at a pace of 2.0 mph for a few minutes, then I increased the incline to 12 for a few more minutes (still walking at 2.0 mph), before officially beginning the 12-3-30 workout.
Even if you're not going to do something like rowing beforehand, it's a good idea to do some kind of full-body warmup before hopping on the treadmill. Then spend a few minutes walking on flat ground before gradually increasing the incline to 12 percent.
