HIIT Training

I'm new to the whole HIIT thing but I can only manage 15 minutes. I do 10 seconds intense on the highest setting on my exercise bike and then 10 seconds going slow! is this right or should I be doing 15 minutes worth of high intensity?

At the end of every one of my sessions, my Personal trainer does 8 minutes on the bike. 30 seconds hard, 30 seconds recovery. Heart rate is also just as important. My PT always watches and makes sure I am at my target levels. If I have far exceeded my target heart rate, I get a longer recovery time, up to a minute instead of 30 seconds. Just enough so that my heart rate is still on point but not crazy.

Thanks for the replies, for nw I'll be sticking to the 10 seconds on and off as I don't think id be able to manage doing more. This is my first week so hopefully as the weeks go by I'll be able to increase it.

I understand, hopefully you can work up to it though. Thats kind of the whole point of the work out. Getting your heart rate up knocking off those calories in a short session.

Hmm, I've been doing 30 minutes on my bike, with the last 10 as HIIT. I do 30 seconds on, 60 seconds off. How does that sound? It sure kicks my *kitten*...

There are lots of ways to do intervals, but 10s/10s is on the extreme end of cycles. I've not seen a published workout that is structured like that for a straight 15 mins. The closest would be a 30s/30s or a 45s/15s.
Also, use the setting on your bike to help you judge your output, but your perceived effort would be a better guide. This incorporates not only how fast you're pedaling, but how you're feeling on a given day.

I really like the HIIT cardio workout from the Body For Life plan. It's a 20min workout based on scaling up your intensity minute by minute before coming back for a rest phase.

Based on your perceived intensity (1 - lying down --> 10 all out effort that you can sustain for 1 min)

Min 01: 5
Min 02: 6
Min 03: 7
Min 04: 8
Min 05: 9
Min 06: 6
Min 07: 7
Min 08: 8
Min 09: 9
Min 10: 6
Min 11: 7
Min 12: 8
Min 13: 9
Min 14: 6
Min 15: 7
Min 16: 8
Min 17: 9
Min 18: 10!!!
Min 19: 5

I need the break after each minute at 9, and after 10 I'm pooped!
I've used this on the stationary bike, elliptical and treadmill. The first few on each different machine are a breaking in period where I figure out what level and speed to use for each effort, and I track these so I can see how I'm progressing over time as well as looking at the overall distance covered in the session. Of note, I often find that my capacity increases within a workout. For example, my 9's at the end are faster / harder than the earlier ones even in a given workout. But make sure you're thinking about the full minute - I used to burn myself out 15s into my 10 because I was pushing too hard.

Bottom line though - if you're enjoying your current interval splits - keep doing them! I just wanted to demonstrate some other HIIT options for you.

Have fun!

I'm new to the whole HIIT thing but I can only manage 15 minutes. I do 10 seconds intense on the highest setting on my exercise bike and then 10 seconds going slow! is this right or should I be doing 15 minutes worth of high intensity?

I do three different types of high intensity session; 20 seconds by 20 seconds repeat ten times, 400 metres by 400 metres repeat five times or one kilometre by 3 minutes, repeat three to five times. That's all running.

They're all tough in their own way, the intensities on the 20 second intervals are painful, the 400 metre intervals feel as if they're never going to end and the kilometre is actually a bit too far to sustain maximum effort for so it's probably closer to a tempo session.

For me I need to warm up for about 15 minutes before I go into the intervals portion, if I try without warming up I fold quite quickly.

The purpose of intervals is to push you well into your anaerobic range, increasing your oxygen uptake and as a result improving your base metabolic rate. To do that you're on short intervals at maximum effort, so you can't sustain that for a long period.