Is this a good way of HIIT?

[\m/ MANOWAR \m/]

Is switching off with walking/jogging for 30 seconds (lets say, 6mph) and running for 30 seconds (lets say 9mph) a good method of HIIT?

What about the same on an elliptical, every 30 seconds alternating with 7mph and 12mph for about 20 minutes? Would this be effective? Thanks

[Skarhead1]

it'll work