Rock hard abs workout (beating personal best)

As usual I used my cool Gymboss Interval Timer to keep track of my time for this challenge and my Gymnastic Rings for the hanging knee raises.
1. High Knees to Mountain Climbers (10 reps + 10 reps) x 5 rounds
2. Hanging Knee Raises 5 reps
3. Ninja Jump to Half Burpee 5 reps
I completed this workout in … watch the video :)
I hope that you will enjoy this workout as much as I did and thanks a lot for your comments and your opinions. Also thank you for keeping our conversation interesting yet very nice and positive.
My old time was 15 minutes and 19 seconds.
New personal best was 12 minutes and 32 seconds.

(10 High Knees + 10 Mountain Climbers) x 5

Do 10 high knees as fast as you can and then drop down and do 10 mountain climbers at maximum intensity. Repeat 5 times.

Hanging Knee Raises 5 reps. You can do this exercise by hanging on just about anything. I am using gymnastic rings. It is harder to do this exercise on the rings, because they tent to swing a lot which you are trying to avoid as much as possible. Your hands should be griping the rings about shoulder width apart. Make sure that you are hanging. The rings can be easily adjusted so that you can pull them up higher. Pull your knees up as much as you can as if you were trying to touch your elbows with your knees (that’s my goal for the future). Bring your knees down in a controlled movement to avoid any kind of swinging and momentum. Don’t just drop your legs down.

Start by kneeling on your exercise mat. Jump from the kneeling position into a squat. Put your hands on the floor in front of you and jump with your feet back into a plank. Keep your whole body tight in one line and don’t drop your hips. Jump with your feet forward and again back into the plank. Remember to keep your abs contracted throughout the entire sequence. Repeat five times.