I believe I experienced carry-over from foundation to the heavy bag.
It's been a long time since I actually trained but I still hit the heavy bag on occasion to burn energy or get my heart rate up. Anyway, after 3 weeks of Foundation, I went on the heavy bag again and was surprised by the amount of additional core involvement. The connection between upper and lower body felt really solid. With the wrist exercises from H1 I wasn't as worried about hurting my wrists so I really layed into it and the amount of core activation I experienced really surprised me.
Foundation rocks because the strength seems to carry over into unrelated activities.
I don't really develop fast (super slow actually) in Foundation cause I train to much MMA. But man do my core feel strong when I wrestle. But did so much weight gain that I embrace the higher weight class 