I find the best benefits from activities that you have a difficult, though not TOO hard to do... then doing that all day. Laborious work like digging trenches all day, but adding in the working of chi while doing it can allow it to benefit, not break down. Almost any activity can break down the body without healing from its effects more than the level of damage dealt. I find tree climbing like a monkey and taking a huge mound of large rocks, tossing them all to form a new mound and repeating for hours... These are great full body exercises that seemingly create muscles where their were none lol. Also gripping exercises for martial arts, and low stance stuff for leg strength. Good luck.