This is a great video about how to treat knots and bruises on the shins. Although it’s by a muay thai practitioner and aimed at muay thai people, judoka know that sometimes an overzealous and poorly placed sasae-tsuri-komi-ashi can have the same effect as an intentional kick.
In summary, she says to use ice only directly afterwards, and thereafter heat and massage. All solid advice. To tune up your body for judo, be sure to stretch on your days off. Push-ups, sit-ups, and some light jogging will all make judo practice more fun and enjoyable. The essence of judo is in technique, but if you’re too tired to apply the technique knowing it won’t help!