Light and Sensitive
There is a difference between “Light and Sensitive” and “Soft and Relaxed”. The first is found in nature. Look at an insect as its antenna brushes against something. Watch a praying mantis, it is a perfect example of “Light and Sensitive”.
To become too “soft” is to become too “yin” and lack balance. It is to become weak. Weak does not survive in nature.
People start out to “Yang”. They use to much power in each movement, they are stiff and have too much tension. They don’t feel, and can’t adapt very quickly to changes their opponent makes. They tend to over extend and put themselves off balance unnecessarily, and for longer then needed. This makes them easy to manipulate. They lack “Yin” to balance their “Yang” , so emphasis in training is often about seeking to develop “Yin” in order to have proper balance.
So one of the first things they are taught is to relax, and not use any muscle tension that is not required. This is an important skill to develop. It is developed through proper training and repetition.
Softness is a term used often in conjunction with being relaxed and sensitive. Many work to be as soft as they can.
Some systems use various methods of push hands to develop softness and sensitivity. This is a great training method, and should be used in some form by anyone training in a martial art.
However many get caught in the trap of working to ever become softer and more relaxed, even to the exclusion of normal exercise. They lose all aspects of Yang.
People that follow this path think they are developing higher levels of skill that may take 20 or more years to develop. They rationalize in their own minds that pursuit of this goal will eventually make them the superior martial artist. This is even while they continue to lose any confrontation with an opponent. If you’ve been training a system for a number of years, and you can’t defend yourself against an untrained attacker, you are practicing fantasy martial arts.
Training properly in an internal style, you will continue to develop higher levels of skill and understanding throughout your life. However if you aren’t learning how to use it from the beginning, and you are intentionally making yourself weak to improve softness and relaxation you’re going down the wrong path.
You must maintain balance between yin and yang to be an effective fighter, and to maintain your health at the highest level. So with this in mind, I suggest you should be thinking “Light and Sensitive” instead of “Soft and Relaxed”