The following is an excerpt from The Ultimate Guide to Bodyweight Conditioning.
The Jumping Lunge
To start with, from a normal standing position, step one foot forward, with a larger than normal step. This forward foot will be flat footed. Bend the leg as the other foot stays in place but raises up onto the ball of the foot. For the jumping lunge you’ll not want to touch your knee to the ground but keep it hovering over it an inch or two. This is the place you jump to from each side. Explosively jump upwards then switch the front leg to the back and the back to the front. Make it even harder by jumping high with each jump.
While simple in execution this is a phenomenal conditioning exercise.
This can be done anywhere at anytime (except maybe on the a floor above someone else where the jumping might disturb them).
Simple One Exercise Conditioning Workout
Set a timer and just try to do it for two minutes straight with a fair amount of speed and explosiveness.
How many reps do you get?
How high are you jumping?
Can you go longer?