Hyung must be performed in a powerful, but exact manner. While training with a partner in class, you must execute powerful techniques, but with absolute control so you do not harm your partner. Both of these actions require intense mental concentration. If you practice intensely and concentrate on a performing a difficult technique, such as a jump-spin side thrust kick, at some point you will achieve a "breakthrough" (the point in time after which you are able to perform the technique consistently). The technique that seemed impossible in the beginning will now seem easy. To achieve breakthrough on a technique, you must concentrate on the technique and not let your mind wander. After achieving breakthrough, you will find it easier to concentrate on that technique. The ability to concentrate your efforts to complete a task will also help you in your daily life and at work.
To experience a good training session, you should relax and have fun, but you still must train very hard. Always put one hundred percent of your concentration and effort into every class. When the mental and physical aspects come together, you will feel great and have a sense of achievement. If you are sick or injured, do not go to class. Stay home and get well, so you may train at one-hundred percent when well. If you are merely feeling "down' or out of sorts, you may find that as the class progresses you will feel better and be able to perform at full intensity. At the end of each training session, if you have put forth maximum effort, you will be exhausted. As your fitness level improves, you will have to do more and more to reach exhaustion. It may become convenient to not exert yourself physically or mentally, so that you may stay comfortable. However, if you only do what you can comfortably do, you will not progress. Progress comes from doing more than you thought you could do. A class session in which you have mentally and physically challenged yourself will always be a good class.