Today is victory over yourself of yesterday; tomorrow is your victory over lesser men.
Thugs attack you in order to overtake you in the fastest, easiest way possible. They hope you aren't prepared for their assault, and they certainly aren't going to give you some extra time to get prepared out of some sense of fair play. You have to be prepared before you run into trouble. You have to be preparing for this moment daily. This is what your physical training is all about. If you allow your laziness or melancholy attitude to get in the way of your training today, you will not be prepared for the unexpected challenge tomorrow.
Musashi put it this way, "Study strategy over the years and achieve the spirit of the warrior. Today is victory over yourself of yesterday; tomorrow is your victory over lesser men. "What you do today determines how prepared you will be for tomorrow's challenge. To be prepared, you have to continue your training and keep your body in good physical condition. This includes weight training, stretching, weapons training, and your martial arts training.
Excerpt from the book Modern Bushido: Living a Life of Excellence