All Yang - (activity) without Yin - (rest and recovery) equals burnout. Your body (and your spirit and mind) is like a vessel that is put on a hot stove when you perform activities. Heat is naturally generated, which is not in and of itself a bad thing. What is bad, is when that vessel has no water. The vessel can warp and break.
The most amazing thing happens, however when that vessel replenishes with Yin energy. Steam is created and the energy created is more than the sum of its parts (fire and water)!
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