Random workouts are a fun way to shake things up.
They’re a particularly cool idea for martial artists. If you want to be ready for anything real life throws at you, try throwing unpredictable stuff at yourself in the gym.
I have two dice — one for Skills, the other for Fitness. I roll both dice, warmup for ten minutes, then practice whatever the Skills dice says, followed by whatever the Fitness dice says.
My Skills dice has Heavybag, Knife, Cane, Kicks, Shadowboxing, and Wrestling on it, while my Fitness dice has Constitutional (twice), Hiking, 10-Min Max Output, Pyramid, and Sprints on it.
You can get wooden blocks at a craft store, or you could steal a set of dice out of that old Milton Bradley game in the back of the closet and put stickers over the dots. Hobby shops specializing in games used to sell blank dice, but I haven’t been in one in awhile so I’m not sure they still do. If you can’t find a way to make dice do something else. Doesn’t have to be dice…you could just as easily put scraps of paper in a fishbowl and make a workout raffle, or write on ping-pong balls, put them in a cage, and play workout Bingo.
How you do it doesn’t matter. The point is that introducing some randomness into your workouts is a great thing.