Hi dpiglet--I loved Winnie the Pooh when I was a kid. Is that where the "piglet" comes from?
My first Cathe tape was The Wedding Video, and I was able to handle it, but needed more choreography. I quickly ordered Stepworks, and I distinctly remember feeling that just the warmup was enough of a workout for me! I got through it, but here are some suggestions for modifying. (Iknow you're talking about Imax, but the same applies)
1. DO NOT feel like you have to do what Cathe does! During the warmup, do not add the jumps, the ball-change, anything with impact keep low-impact.
2. During the intervals, do the same--keep the impact as low as possible during the 6 repetitions of the choreographed moves (the part before the blasts). Once the blast part starts, go moderate to all out, but only for as long as you are able to do so with heavy breathing, but not to the point of "my heart is filling up my whole body with its beating, I am gasping for breath, I feel nauseated, and I want to die". This may only be 10 seconds of the interval blast, and then you do knee ups for the rest of the blast. 10 seconds will grow into 20, 30, etc.
3. If you complete an interval blast, you can slow down for longer than Cathe's recovery phase. When she and the amazon girls behind her begin the next interval (not the blast,but the choreographed section), you can still be doing side steps for as long as you need to. You have to modify it to your needs.
4. Remember that this is supposed to be more uncomfortable than your average aerobic tape. But, it isn't supposed to make you feel sick! It should wipe you out in a good way ;-)
5. Compete with yourself, not with the goddesses on the screen!
6. Finally, you could do some of the following: a. Try the warmup and one interval, cool down and call it quits. b. Schedule another video, but throw in one interval before the cardio part of your chosen video starts. c. Buy Intense Moves by Gin Miller and work up to Imax!
Good luck--you will conquer this video. Just give it time!
Wendy