Is Running on the Treadmill Always a Must?

Even though I have targeted the treadmill as the tool for meeting my running goal, sometimes I just don't feel like running. To make the treadmill more challenging without running you need to use the incline. After warming up for about 5 minutes, I will increase the incline every minute for 10 minutes or until it gets steep enough where if I increase any further I have to hold on to the rails or it just gets too tough. The second half of the workout I bring the incline down and increase the pace each time I lower the incline until my pace is at a point where I have to start to jog. By then it is time to do a 5 minute cool down (total time = 30 minutes). I don't do this often by when I need to take a break but keep on the treadmill this keeps me on track.