Are you shifting forward on purpose on the ascent?

Yes. It is functional fitness for what is called a “duck under” in wrestling. So I do that turn and lunge while you are driving against me to get under your arms (hence “duck under”) and then I drive up and into your legs/hips to tackle you. That’s the movement I am simulating with that first exercise.

Interesting exercise. I think it would work better with something like a sandbag, where the weight is distributed more towards the center. That would mean less rotational force to worry about and more focus on the actual duckunder mechanics. But I don't know If there even are sandbags heavy enough for this and the grip would also be an issue.

I agree about the sandbag, but, yes, I haven’t been able to find anything large enough. I kind of just rolled with it. I will say that stopping that rotational force is an AMAZING core workout, so I just sort of count my blessings here.