Its no different than squatting 1000lbs, climbing mt everest, or anything else that requires a lot of training. You build the support structure and then are able to execute the action. Try the former without training and.....there's usually support structures to prevent you from being crushed. Try the latter, and you might be dealing with cerebral edema...
Improper practice is the most likely cause of qigong insanity. That's why its important to learn and practice correctly. You dont need to fear any of that training, just respect what it is and only practice it after you have prepared properly. If you're thinking of the view from the top of the mountain while climbing, you're missing the scenery along the way