I tried to do HIIT cardio on a tredmill on the gym, well its not too easy. Because it takes awhile for the machine to get up to the speed I set it to.

I am wondering if this is good:

warm up: 5 minutes of light walk

cardio:

30 secs walking
2-3 minutes running 7-8 mph.

30 secs walking
5-7 minutes running 7-8 mph.

1-2 minutes walking
5-7 minutes running 7-8 mph.

I do that for a total of 20 minutes... too much? too little.. I am on the air with this..