This workout routine is a great way to build endurance and push your cardiovascular system.  This type of workout is great for fighters and gym rats alike.  If you give it a try, let me know what you think.
For this workout, perform boxing combinations on even numbers starting with ten and go down to two.  For kicking repetitions, perform kicks from two to ten.  After each boxing combination, perform the kicking drill.  For example, you complete ten of the jab and cross combination.  Then, you perform two kicks.  Next you perform eight boxing combinations, then 4 kicks.  Make sense? 
First Set
Jab / Cross Combination: 10, 8, 6, 4, 2
Round Kick: 2, 4, 6, 8, 10
Pushups, Normal: 25
Pushups, Vertical: 25
Pushups, Alternate: 25 each side.
Switch Sides and Repeat
Second Set
Low Hook / High Hook (same hand): 10, 8, 6, 4, 2
Thrust Kick: 2, 4, 6, 8, 10
Crunches, Normal: 25
In n’ Outs: 25
Side Oblique Crunch: 25 each side
Switch Sides and Repeat
Third Set:
Alternating Punches: 20, 20, 20, 20, 20
Side Kicks: 2, 4, 6, 8, 10
Squats: 25
Lunges: 25 each side
Calf Raises: 25
Switch Sides and Repeat
This can take a good half hour to forty five minutes to complete.  If you are just starting out and this is difficult for you, continue doing this routine for about a month and you will see a difference and feel better.  If you are a more seasoned athlete and this was rather easy, I challenge you to mix it up:

•  Perform the whole workout twice
• Perform 20, 15, 10, 8, 6, 4, 2 and vice versa for kicks
• Add more calisthenics or plyometrics to the mix
• Add more sets of workouts with different kicking and boxing methods

There is no limit to how hard to train and how hard you push yourself.  The only difference is how hard are you willing to train.  I hope this workout does push most of you as it does me.