The Jains of ancient India used the metaphor of the leaky boat to show how, through discipline and training, you can improve your body and mind. Say you are crossing a river in a leaky boat. To get to the other side, like the proverbial chicken, you must first plug the leaks, and then bail water out of the boat. If you bail before you plug, you won’t stop the water coming in, and if you plug but don’t bail, you still have water in the boat with you.
Plugging is like sticking to a rule, program or diet that stops something bad from coming into your life. Jains are famous for their non-violence and vegetarianism, which is why they do not eat root vegetables, because you must kill the entire plant when you pull it out of the ground.
Bailing is like exercise or training that gets rid of the bad that is already in you. Jains are also famous for spending long periods meditating and standing in yogic postures in the jungle, sometimes for so long that vines were said to grow up their bodies.
Jains believe that it is only by this two-pronged plug and bail strategy that the individual can be fully liberated and be united with the cosmos, escaping the rounds of reincarnation. Regardless of what you believe, it is also an excellent strategy for training and improving yourself.