Are the “The Muscle-Tendon Change” (Yi Jin Jing) exercises done in a relaxed way (like Taijiquan) or in a tensed way (like Sanchin)? Some say that the exercises must be performed in a relaxed way, also others say that exists also a 'dynamic tension' version of the Yi Jin Jing.
Is the purpose of the Yi Jin Jing to build muscles?
Dynamic tension exercises are muscle/power building exercises and are greatly explained in two books: Pushing Yourself To Power by John Peterson and Dynamic Strength by Harry Wong.