Morning everyone!
3monkeys well done you! That takes dedication to carry on when you're away, something I'm not very good at doing!
Lizzy, I'm not sure if there are any specific DVDs for HIIT. There are in my turbofire pack, but that's a pack of about 10 DVDs that includes other longer workouts too (and costs about £100 for the lot
!)
Notyummy was telling us about tabata training (have a google), which is very similar I think. You go all out on a cardio exercise for 1 minute, then rest for 1 minute, then repeat the cardio, rest etc. You can do as few as 3 mins cardio (with rests) or more. I think the longest HIIT DVD I have is 25 mins (bearing in mind that includes rests + warm up / warm down).
So, if you picked any kind of cardio (high knees, jumping jacks, mountain climbers etc.) and really go for it as above, that's a HIIT basically.
You can google 'tabata timers' and find stopwatch type timers that time your cardio and rest phases. I think the key is really giving it everything - if you do that, it's apparently a very effective way to burn fat (around 9% more effective than 'traditional' cardio workouts according to turbofire laydee).
Will be doing my 55 min turbofire DVD later. My jeans are definitely feeling more snug, no surprise at all to be honest! My lovely dog is suffering very badly from arthritis and we've been told not to walk him, (started around a month ago) so it's really reduced the exercise I'd normally do in a usual day. He's a ball of energy usually and it's really hard seeing him struggle recently, he's 13 
Will check in later 