Leapfrogs are similar to the standing broad jump. The difference is that leapfrogs are performed in a repeating manner, as opposed to stopping after each jump. This exercise will help build strength in your entire leg as well as endurance.
To perform leapfrogs, all you need to do is jump forward with as much force as you can. Once you land, immediately begin the next jump. Try to get your jump distance to a point where you don’t have to pause and reset your stance. The need to reset often occurs because you’re trying to jump too far. Also, you can perform leapfrogs with your feet together or spread slightly apart.
Leap Frogs Video (Remove the reset time that this guy takes in between jumps)