Student: Sensei, how do I hit the target every time?
Sensei: You practice hitting the target, every time.
I saw this meme floating around, and the quote, the saying, in it reflects how one should practice.
There's another saying that you probably have heard as well, it is better to practice one technique a thousand times rather than a thousand techniques once. However, this saying has been taken to meant repetitions. If it's only merely repetitions, then it is not enough even if you do it a million times. Why is that so? Practicing something that is wrong a thousand times won't make it right, it will just mean that you become good at doing the wrong thing.
In Japanese budo there are 3 words that you usually hear which in English are all taken to mean "practice" or "training":
- Keiko (稽古)
- Shugyo (修行)
- Renshu (練習)
Keiko literally means "tracing the old". This is a part where one sees how the elders do it and replicate it. Replicating not merely in form, but in totality, the process and outcome. In the eastern arts, the end does not justify the mean. One must follow the process in order not to miss important details that are not visible in the outcome. In the east, the arts are process based, not result oriented, though the results are clearly visible.
The only way to quickly get results is to go through the process diligently and correctly. Tracing the old is not merely copying, but understanding why your predecessor could achieve results through the given process. As the word suggests, you have to have something to trace to, a point of reference. This part is saying that you will be under the guidance of, receiving instruction from, somebody that is more senior. Even though you are doing self-practice (独稽古) or free-practice (自由稽古) the guidance is still there, in the form of what you have traced previously from your elders/seniors.
Shugyo could literally mean conducting self discipline, mastering oneself. This is usually related to spiritual or even ascetic practices. This is used for budoka as well because they are seen in the process of achieving enlightenment. A budoka is even sometimes called a shugyosha (somebody that practices shugyo). This is a part when one practices religiously, being really serious about the discipline that one is studying. It is not merely self-practice. If we could see spiritual shugyo of Buddhists or Shinto practitioners, for example, it takes dedication, not merely a 2-3 minute meditation. The same could be said for budo.
This is the further exploration of your keiko, it is more than just self practice, but you really do it to achieve understanding of what you have learned. In budo, the only way to really understand it is to experience it (taitoku). Finding out the correct process, practice it, experience it, have the discipline to train in it.
Renshu is the part that do actually mean training, practice, or repetition. This part is where one repeats everything that one has learned and experienced. This needs to be done correctly based on one has received through keiko and shugyo, this is the part where one practice hitting the target each time, doing the repetition correctly.
The three terminologies are not interchangeable but they are connected, as there are philosophies behind the words used, and each aspect of practice includes all of them.
Don't let this confuse you. Just forget about it, and keep training...