One of the most intense pieces of training equipment you can use in your MMA workouts is the heavy sandbag. Just the other day I decided to defer from my regular leg training day and just do circuits with the heavy sandbag.
As I mentioned before, one of the greatest parts about MMA workouts is that you can vary your training often enough to never get bored with your workouts - and there are all kinds of ways to train with the sandbag.
One of the best overall MMA conditioning workouts you can do with the heavy sandbag is to perform circuits with it in the same amount of time as the rounds in a fight. Here is an example of 1 circuit in the MMA workout I performed the other day. Take note that each circuit requires that you don't put the sandbag down the whole five minutes
MMA Workout w/ Heavy Sandbag Circuit (Round 1): 5 Minutes
1) Bear hug sandbag and walk for 1 minute
2) Shoulder sandbag and do 10 squats
3) Place sandbag across right shoulder and do 10 squats
4) Place sandbag across left shoulder and do 10 squats
5) Cradle sandbag in front of you and do 10 squats
6) Hold sandbag at arms length in front of you and walk for 30 seconds
7) Keeping same grip from previous exercise, do 20 stiff-legged deadlifts
8) Shoulder sandbag and walk for remainder of the time
Performing this circuit or one like it is a VERY good MMA workout that carries over to the type of conditioning needed in a mixed martial arts fight, especially for grappling.
The reason being is that a heavy sandbag simulates an opponent because it is a heavy, awkward, unbalanced, and constantly shifting weight. Doing quick and explosive squats with the weight in different positions simulates the different positions and resistance when attempting to pick up your opponent and/or take him down.
By never putting the sandbag down, you train your stabilizer muscles as well as tax your isometric strength, strength endurance, and grip strength endurance (the fatigue you feel after a heavy sandbag workout is very similar to the fatigue you feel after an intense grappling match).
In terms of aerobic/anaerobic conditioning, heavy sandbag workouts can train both forms of endurance that transfers over very well to MMA. If you wanted strictly an anaerobic workout, you can do interval training with the sandbags, such as quick sprints or as many squats as you can in a 30 second period followed by short rests periods. By doing circuits like the example I gave above - doing several circuits in 5 minute rounds with a 1 minute rest in-between them - your aerobic conditioning will come into play as you get into the fourth, fifth, and later circuits.
So if you want to change up your MMA workout routine and get an intense full body strength and conditioning workout, incorporate some heavy sandbag training in your MMA workouts.