There are a lot of different ways to cross train. One tool that has changed my Brazilian jiu-jitsu game is the exercise ball (also called a stability ball). If you have never seen an exercise ball used for Gracie jiu-jitsu, check out this video (sorry for the weird music…the guy knows how to move, but may need some help with his soundtrack choices):
I love the exercise ball for jiu-jitsu because it teaches a lot of different principles.
1) Balance and flow come from RELAXING the right parts of your body: If you are tense, you will lose your balance. The ball will “sweep” you. You need to relax the majority of your body and make minor adjustments to keep the main balance point. This is also helpful with your jiu-jitsu because it conserves energy and allows you to roll better longer.
2) A lot of CONTROL comes from your HIPS: You control the ball with your hips. You determine the direction it can roll and the places it will stop. This is a great concept for top positions in BJJ: Your hips create pressures and barriers for your opponent when you are rolling!
3) Mistakes happen, but you can MITIGATE the consequences if you FLOW: Tensing up and holding onto a bad position or base will get you swept or subbed. If I relax and counterbalance the mistake I may be able to salvage the position, deter my opponent’s game plan, or go to the next best position. I need to flow instead of panic.
Get started! There are a lot of videos out there to give you some ideas of where to start. You can also just start experimenting on your own, even if it is just starting with basic balancing positions (butt, stomach, knees). Have fun!