Whenever I’m strapped for time and equipment and still need a solid workout, I turn to the burpee. Burpees are bodyweight exercises, and thus require no equipment or weights. They are full body movements that employ every muscle group, require only as much space as you need to do a pushup, can be done anywhere, can be done slowly and methodically or quick for a sprint-like workout. While burpees are great for all the reasons I listed above, there are some reasons you might want an alternative.
(This Mark's Daily Apple article was written by Mark Sisson, and is narrated by Brock Armstrong)