i've heard that internal training done incorrectly can cause internal injury as well as affecting the mental state of the practitioner. hallicunations, vomiting, nausea etc.
what are ppls' ideas on this and experience?
can different internal training methods from different systems which train your internal energy flow clash and also cause problems if u try to train both systems at the same time?
i think in cantonese phonetically it sounds somethnig like "jouw for yup more"