Convinced on HIIT, But How Do I Change Over

I like the idea of spending a lot less time on cardio, and it sounds as if I need to refocus on weights. 

So how do I make the transfer over to the HIIT program from what I am doing?  I don't do the treadmill because of back injuries.  So that leaves the stepper and recline bike. 

On the bike I am doing a total of 20 minutes.  I start the session with 4 minutes at 160 watts, then 4 minutes at 190 watts, then 4 back at 160, 4 at 190, then finish with 4 minutes at 170. 

Now on the stepper I am doing a total of 12 minutes at 100 watts, changing between forwards and backwards every 2 minutes. 

So I would like to come up with a HIIT program for both machines, allowing me to switch back and forth to hold off the boredom. 

But I don't think I need to start the HIIT a the bottom.  Hope someone can give me a starting point?

you can start HIIT with 30sec of sprint/vigorous workout/ 90secs recovery w. moderate/light workout. do about 20 minutes of this and you should be out of breath when your done.

I do 30/60 on a tredmill. sometimes for my 60 i'll jog lightly.

Bascially HIIT can be done on any type of equipment.  You can do it outside on a track, at the park, or with a jumprope. 

Most people are advised to only do it a few times per week and sessions only last 15-20 minutes. So you won't get bored, and chaning machines really isn't an option.

If you still want to burn calories after that then do some regular steady state type cardio to burn a few more calories.  But don't overdo the cardio or it will cost you muscle.... 

HIIT -- pick an activity and go as hard/fast as you can for 30 seconds or so.  Then slow down -- and I mean waaaay down.  If you were sprinting, then slow down to a walk or a light jog in order to let your heart get back to a recovery rate fro a mintue or 2.  Go through that cycle 5-6 times and then you are done. 

It doesn't even have to be cardio.  You could do complexes with weights if you want. 

I don't have a good enough idea of what a watt is, so I don't know how intense your current workout is, but are you sure it's safe to start on real high intensity workouts?  Just because it get's recommended to everyone doesn't mean it's safe/effective for everyone.

If you want to start doing some more interval-style cardio just pick up the pace a little for 30 seconds or so and then back off for a minute or a minute and a half.  lather rinse repeat.

Well, on the recline bike, the intensity is pretty close to the top.  And the stepper is pretty intense as well. 

You can actually do HIIT in any number of ways.

Now I read in the other thread that you have had lower back problems. I was just curious, do you ever feel back pain when doing squats? If your form is good and you don't feel pain with squats, you could do HIIT with bodyweight squats. No bar, no weights, just squatting up and down using your own body.

Warm up for 3-5 minutes to get your heart rate up a bit. Then just do bodyweight squats over and over for 15-20 seconds going as deep and as hard as you can. Rest 45-60 seconds depending on how long you go (starting out you rest for 3 times as long as the sprint). Then do it again. Keep switching off between 15-20 seconds of squats with the rest intervals. Since you are just starting out I recommend 10 minutes because your body won't be used to it. Doing the intervals for 10 minutes @ 20/60 would have you do around 7 intervals. As you grow more accustomed to it, you can up the amount of time you do the intervals.

Like I said though, it all depends on how good your squat form is. If you have felt lower back pain from squatting, I would recommend the stationary bike. Keep the resistance somewhat low the whole workout, and just pedal as hard as you can during the sprint phases, and pedal slower in the recovery phases.