Standing Practices
and the Iron Shirt 1-2-3 series,
Introduction.
Standing practices,
often called zhan zhuang, are important. They exist in the
vast majority of Taoist systems of cultivation. If you happen to read
about various systems of qi gong, you'll see that there are entire systems
where standing postures is all that they do. Additionally, virtually everyone who
teaches tai chi push-hands mentions that static standing postures are crucial
for establishing root.
Aside from the internal martial arts, an abiding connection to the earth has substantial general health and psychological benefits.
For those of you that have come into Taoism from spiritual
traditions that predominantly (or exclusively) focus on heavenly energies,
standing postures can be a life saver. A healthy human body is made up of
a balance of heavenly and earthly energies 
:
High meditative
energies tend to be subtle, and expansive (which, in the right balance, is very
healing).
Much of what makes a physical body robust, healthy, and durable is a
set of dense rich tissues and substance: dense bones and marrow, rich nourishing
blood, and so on.
Chinese medicine sees the body as progressively layered, with deeper layers containing reserves of physical stamina, your "constitutional reserves" if you will. If you, over years, focus excessively on energies that are subtle and expanding, you run the risk of gradually dispersing the denser reserves of your physical health. (This is not to entirely disparage such traditions, which often have much to offer in their own right!) Integrating with the earth is one aspect of remedy for that sort of imbalance, and standing practices are the foundation for integrating earth energy.
This is not to say that Taoist standing practices integrate earth energy only (though that is often taught first). A major key to further progress in standing practices is to blend earth and heaven, through the human body, harmoniously. Heaven descends, and enlivens earth. Earth rises, and stabilizes heaven. Finding out how this process connects and blends with the aspects of the human body/psyche is much of what standing practices are about. Heaven, earth, and man.
On the physical, the pathway of heaven ~ human substance ~ earth integration, which the standing practices promote, is fascia ~ sinew channels ~ tendons ~ joints ~ bone marrow. The 1~2~3 steps, below, parallel that. (On a more subtle level, the extraordinary vessels are pertinent.) It is the interaction of heaven and earth through the human body that does the packing, changes the tendons, and washes the marrow. The heaven ~ earth dynamic is the authentic context of these practices.
Ok, so, that's the good news - now for caution. As with any of these effective tools, going over-board is counter productive. Listen to your body, learn from what it is saying. Working hard is one thing, "blasting through" is another (and will get you into trouble). A gentle approach and a general understanding is sufficient in the beginning. As your practice progresses and you want to approach later techniques, an increasingly detailed knowledge will serve you well.
Balance and harmony.
NOTE:
In the HT system, standing postures (zhang zhuang) are initially taught as part of HT's "Iron Shirt 1", but standing postures are not at all isolated to IS1: they are integral to all of IS1-2-3, and a main-stay of Taoist cultivation in general - so they are taught in the beginning. The sections, below, assume that zhang zhuang is recognized and present - and so go on to focus on the topics more specific to each of IS1-2-3.
Sections
Lower tan tien breathing.
Sinew, tendon changing.
Gentle marrow washing.