I have "Enter the Red Zone with Team Video Fitness". It's fun to see some people you "know" on a video but it's not my favorite Spinerval. Like most Spinervals, it's interval training but Coach Troy doesn't allow the riders to recover after the high intensity work. He actually seems pleased that they're still at 85% or higher during recovery.
I don't get the iso squats. You get off your bike after an interval, do some pulsing squats for awhile (ok so far) & then freeze at the low end for awhile. My heart rate just plummets which seems like a good way to drop over. I modify.
Finally, one should be familiar with good spinning technique because the camerman keeps focusing on a rider who is not using enough tension. Her legs are flying & her butt is bouncing on the seat. Troy corrects her several times, but there's still a lot of footage of this rider which someone might try to emulate if they didn't know better. You don't bounce on the seat if you're using enough tension.
Brenda has beautiful cycling form. She looks very strong.
Debra
Mari