So Rooster, do you think that I could do this with my stationary recumbant bike (arthritis) ?
Yes. HIIT exercise can be done with all exercise. HIIT only means that you are working as hard as you can for limited amounts of time. This definition will vary with the individual, their physical condition, their medical issues.
If you are able, with your arthritis, to do HIIT, it is great.
Pedal hard for a minute. Then at a comfortable rate, that still keeps your heart elevated for another minutes. Then another really hard minute. Than another comfortable minutes. Until your minutes are up.
I do mine on my indoor bike trainer.
The program I am using at present for my HIIT is a slow warm-up for 10 minutes and then 4 internals of only 30 seconds with each interval followed by a few minutes to catch my breath. In each of my intervals, I go all out (holding nothing back).
If I were doing anything other than riding my bike trainer, I would lose correct form. For example, I have a rowing machine that I use a couple of times a week. If I ramp up the intensity on my rowing machine, I cannot maintain the correct form and my back ends up hurting the next day. Same for all the Crossfit exercises.
I think any exercise that requires correct form is not good for HIIT because you cannot pay attention to form while at the same time driving yourself to maximum output.
BTW, If you are not currently doing hard cardio workouts, start slowly. You can still do interval work but be careful to build weekly by a adding intensity.
Anyone not already fit cardio-wise should not do HIIT.
As a final note, I chose 30 second intervals because it is just about 10 seconds more than I can bare. That means that the last 10 seconds are just hell (and I think that's the general idea). If my interval were any longer, I would start pacing myself and that's not the goal.
The goal is to go all out for each interval. Some folks even barf when it's all over...and that's a good thing.