Here's my Thursday workout for the next three weeks. It is called the threshold method and also comes from Joel Jamieson's book, Ultimate MMA Conditioning.
10-20 reps / 3-5 rounds / 60-120 seconds between rounds
Glenn asked me the other day about a workout that he could do when away from the academy that was more than just lifting weights. This is my go-to workout for all purposes, but it is especially good because you can change the pace to make the workout more aerobic or more explosively-oriented.
Some of these moves have names that I invented because I couldn't figure out a better way to describe them. "Hip splits" for example, has you sitting as if doing a hurdler's stretch with your back leg, but instead of sticking your front leg out straight, you curl it back toward you in an L shape. Then you switch sides, going back and forth bringing the front leg to the back and the back leg to the front. Much easier to do than to describe.
If all else fails, you can always just do hipscapes, sitouts, backrolls and technical lifts. Those are the "core four" that work the most essential basic jiu jitsu/grappling movements.