Which sport does not involve a ball/ balls?

Aikido is a modern Japanese martial art originally developed by Morihei Ueshiba, as a synthesis of his martial studies, philosophy and religious beliefs. Ueshiba's goal was to create an art that practitioners could use to defend themselves while also protecting their attackers from injury. Aikido is often translated as "the way of unifying (with) life energy" or as "the way of harmonious spirit". According to the founder's philosophy, the primary goal in the practice of aikido is to overcome oneself instead of cultivating violence or aggressiveness. Morihei Ueshiba used the phrase masakatsu agatsu katsuhayabi" (正勝吾勝勝速日, "true victory, final victory over oneself, here and now") to refer to this principle.