In relation to my comment above:
... I did see a good deal of muscling thru techniques with arm strength...
I should begin by stating I'm not a member of the school which presented these video clips, so I am not familiar with their training program. Therefore my comments are base solely on assumptions made by viewing the video & other photos on their website.
It appears that they use heavy weights for strength training as evidenced by the iron balls in several photos. Now on first blush, many practitioners of
taijiquan will criticize the use of these weights, & rightly so, because their use will cause muscle tension & thus hardness. Since the secret of
taijiquan is "steel hidden in cotton," therefore, exercises that harden the outside, the muscle, are general out. However, we should note that every system of
taijiquan employs a type of weight training, we just don't usually thing of it that way because of our approach to this training. What I'm speak of is
zhan zhuang. When we are "post standing" with our arms out, we certainly are hold up weights, our arms. (Anyone who doesn't think this is weight training should try it for half an hour. At GRTC, being able to stand in
zhan zhuang for 30 min. is the minimum requirement to partake in our
sanshou class). Once a student's body mechanics have developed enough, they can progress to weapons training.
Jian training begins with, you guessed it,
jian basic stance, which is just another way of saying
jian zhan zhuang. Anyone who has recently begun this practice & who is using a real weight sword, will tell you, 5 minutes of basic stance feels like 20 minutes of empty hand
zhan zhuang at first. From there, a student may progress to spear training, which includes spear
zhan zhuang. This involves standing in a horse stance & with one leg forward with a 10 foot hard wood spear at shoulder height & parallel to the ground. The Yang Family's
taiji spear training also involves slowly raising the spear from the ground to a 45 degree upward angle.
So I would say that its not a question of whether there is weight training in
taijiquan, but when a student should begin this training & how to preform these exercies correctly. We should note that there is an axiom in
taijiquan that the heavier the weapon, the softer the student needs to be. This is because if one moves on to heavier weapons too soon, instead of using internal power, which takes time to develope, the more familiar external muscle strength will be employed. I suspect that by moving to heavy weights too quickly, these
taijiquan practitioners may have reinforced their external strength & muscle use, instead of taking time to soften & build strength from the inside out.
I hope these ideas & information are useful.