This entry is based more on my own personal experiences than on specific training in the world of horses and horsemanship. Over the years of taking dressage lessons and attending dressage clinics, I have recognized that when I'm learning something new, or attempting to correct a flaw in my aids or in my position, as soon as my brain becomes over-engaged, my body responds with tension. When my body tenses up, I am unable to be a truly effective rider. I have to first become aware of the tension, then take a few deep breaths to release that tension, and focus on relaxing my body...not becoming a limp passenger, but becoming a relaxed, supple, confident rider. This allows me use my brain to guide me, as I position my body correctly and give my aids correctly.
Tension also creeps in if I'm not getting the response from my horse that I want. Too often, I get frustrated, thinking that either I'm doing something wrong or my horse is simply not responding. Again...my body tenses, too often my default is to get louder and stronger with my aids, which usually results in tension in my horse. It's much more effective to take things back a step, breathe, relax, and either try again, or ride through an exercise that will help horse and rider ease into the exercise that has been causing issues.
That is so true! I. too, tend to tense up when things are not going my way, or I am nervous, or feeling pressure from somewhere. I am working diligently to release my tension, so that my horse can do the same.