A Low Impact 4 Minute Fat Loss Cardio Circuit

So this article is about that 4 minute fat loss cardio circuit I discussed a few weeks ago. In case you missed it and the accompanying video I created, you can see it by going to my blog at http://fitnessplanning.blogspot.com.
To refresh your memory, I was saying that this 4 minute fat loss circuit is a better way to burn fat than doing a long, slow boring walk. It gets the heartrate pumping, gets you burning more calories, and if you are combining it with strength training, you will continue to burn fat all day long.
I had a few comments that some of the exercises I was doing in the circuit were to high impact, or hard on the joints for people who have tender knees, hips, or ankles. So, I'm going to describe a low-impact fat loss cardio circuit that you can do to substitute.
Do not confuse low impact with low intensity. These movements are supposed to be easier on the joints, but you still want to do them as hard and fast as you can. The goal is still the same. You want to get that heartrate up and be breathing as hard as I was during the video.
So here are the 4 cardio exercises I came up with to improve fat loss.

1. Walking Suicides - You will have a path of say 10 yards (30 feet). You will walk as fast as you can to the 5 yard mark, walk back to the starting point, walk up 10 yards, and walk back to the starting point. Then repeat. The whole time, I would make big motions with your arms. This will help get the heart pumping harder and spend more energy.

2. Step-Ups - Pick a really low step, 6 inches high will say. And step up with both feet, then down with both feet as fast as you can. If you have joint problems, then you don't want the step to be too high. Once again, I would pump your arms as you are doing this to get the heart going.

3. Side to Side Touches - These are real simple. Just move side to side and while you are doing it swing your arms with big motions. Either move your arms in big circles, clap in front of you, but just move the arms.

4. Shadow Boxing - If you stand stationary, punch in the air, but get your body into it. Punch hard and punch fast. This will really get your heartrate going. Please don't throw your arm out though.

So those are 4 exercises I came up with that might help you do your cardio routine yet, keep it low impact for the joints. Once again, I would try to do each exercise for 15 seconds then rest 45 seconds. Then hit the next exercise. All 4 exercises will take you 4 minutes to complete and 3 circuits of those will take you 12 minutes to complete.
Try it out and let me know what you think. I am always trying to tweak my program, so your suggestions would be appreciated. Especially if you have a few more exercises that you have done that I might not have thought of.