My cousin was in the Forces and practiced Burpees religiously: fitness, strength; this exercise has it all.
Moreover, Burpees are a terrific exercise with the added benefit, you can practice them anywhere. (I sometimes use them as a warm-up before a run, perfect!)
Lee
P.S. Your 80 seconds performing the plank exercise is impressive. Try adding 10 seconds or so at a time, and see how you go. Good luck!
