I know that sounds like a lot, but you are allowed to break it down however you wish. If you have more free time on one day, you may choose to do 500, and do 100 on another day. The purpose is to get cardio in and work those legs.
As we get to it, let's review the proper way to do a jumping jack. Start in a standing position with your arms at your sides. Jump up, open up your legs, and raise your arms over your head. Then return to starting.
One thing to note: Since we will be doing a ton of jumping jacks, make sure you are landing properly. No knees buckling inward. No landing on the outsides of your feet. Try to slightly bend your knees and land softly to reduce the tension on your knees. See the demonstration below for the proper way to land.
Cheers Eights & Weights!