Mitch -
Yes, at the basal level this is very similar to J. Cruz circuits - both involve running and then non running activities to get a long, challenging workout. One level deeper, the Cruz circuits are more balistic - closer both metabolically and plyometricaly to the sprint drills near the end of the tempo warm-up (see the other videos on Runnerspace) where as the circuit your watching is simply slower than threshold pace then hard General Strength, but nothing that can be classified as plyometric or can be thought of as power development (MB HT - med ball high toss is the closest, but she's been doing it for 3 years so it's just something that makes here tired - likely doesn't recruit a ton of motor units). And this leads to the running arm question - that simply an easy way to "squirt lactate" into the system; might be dumb, might be too general and lead to muscle hypertorphy, yet I like it. and I like both the standing and the sitting because you have to use your core to go fast...you simply can go fast with your arms and not engage your core.
Hope that helps - feel free to write follow up and if you joined the RunningDVDs page as a fan then send me your address for your DVD.
