Tsu, Yana and Ganko can't participate in such training because their bodies are still unable to generate vital force.
If he tries it with them, their bodies would explode, he had them train normally, basically exhausting their stamina by letting them run laps around the training ground.
The pet beasts on the other hand have to train their skills in order to expend the large amount of energy inside their bodies.
"Leo! Onichichi! I told you that you only need to train movements! Why are you two trying to do partial training!?" Sean shouts at the two and admonishes in front of everyone.
Using Heal in their current state would leave their bodies more injury rather than heal them, what they need right now is not another infusion of energy but to expend them through training.
Not only that, they are using pills to increase their vital force while using the spiritual energy to refine their bodies.
