OK as threatened I tried Speed today. Looks like it would have been better to try Speed before Stamina as Pearsey has pointed out, but hey ho.
At just 16 minutes it seems like it is over in no time. But it is interval training. Not walking, but a light jog and then a faster run. It can be hard to switch speeds but with intervals of just one minute you are off again before you have time to stress about it.
It was a good workout as Laura says. I'll probably go back to a regular 30 minute run next and then alternate that with Speed and Stamina for a while.