What is seen by eyes is only half seen. Rest half can be seen by experience. The Yognidrasana is perfect example of this statement.
Prima facie, it looks it is very painful pose but for a practitioner, it is very relaxing pose. It looks it is giving stretch to legs only but practitioner feels toning of kidneys, liver, spleen, intestine, gal bladder, prostate and urine bladder too.
The ultimate benefit of any truth can be seen by time only. Yes, by regular practice of this asana nerves gets rest & energy gets preserved for better thinking and excellent work.
So if you really want to enjoy complete truth, you need to visualize that by eyes, self experience and time (by keeping patience). But for that one need to be yogi by body, mind and soul. Then, you find unfolding of layers of truth everyday with new surprises.