Qigong has been practiced with a recorded history of over 2000 years.
But it wasn't until 1953, when Liu Gui-zheng published a paper entitled "Practice On Qigong Therapy", that the term Qigong (Chi Kung) was adopted as the popular name for this type of exercise system.
Prior to that date, there were many terms given to such exercise, such as Daoyin, Jinggon, Neigong, Xiudao, Zhoshan, Neiyangong, etc. - Qi Journal
Stillness and action
It is important to find a balance of yin and yang (=Stillness and action),
not just in Qigong/Tai Chi but in everyday life.
In movement, seek stillness and rest.
In rest, be mindful and attentive.
The rhythm of the seasons
"In Spring, breathe "HUN" for clear eyes and so wood can aid you liver.
In Summer, reach for "SHEN", so that heart and fire can be at peace.
In Fall, breathe "PO" to stabilize and gather metal, keeping the lungs moist.
For the kidneys (Winter), next, breathe "ZHI" and see you inner water calm.
The Triple Heater needs your "HEEH" to expel all heat and troubles.
In all four seasons take long breaths, so spleen (Late Summer) can process food and new things, coming into your life. Helping to digest on all levels.
And, of course, avoid exhaling noisily, not letting even your ears hear it.
The practice is most excellent and will help preserve your divine elixir." - free after Master Sun Simiao (581-682 CE)
The spleen energy
The spleen is also related to the time "between seasons". The time, when two seasons are "fighting" with each other.
Today it snows, and it's the 1st day of Spring. The last few days were very warm, as warm as in late Spring. This time is related to the spleen energy.
The emotion is indecisiveness. When we can't decide, then, the spleen is weak. Qigong offers exercises to balance the spleen energy.
Is the energy in balance, we are flexible and can easily adapt to new situations in our life.