I summarized what we've been doing in our workouts to my friend, who is adding the exercise to his Paleo eating. It is heavily influenced by Crossfit concepts, the Primal Blueprint, the Tabata Protocol, and Ferriss' Four-Hour-Body.
The goal is to spend 30 minutes or less and almost throwup.
I usually chose 4 types of exercises
sprint, chest, stomach, back
sprint, full-body, stomach, chest/back
Full-body, stomach, full-body, other,
A few times we have sprinted, full body, abs, fullbody. Close to vomit.
And we usually do three circuits.
I try to make it different, so we don't get in a rut, or adapt to just the exercise. Some days we do a different exercise each circuit.
elliptical 75-90 rpm, built up to 90 & 2 minutes.
Also used Tabata protocol on elliptical. 20sec@90rpm & 10@50 x8
Started jogging a 220 (.125 miles) at 5 mph, then up to a 440 (.25), then faster, 6mph, and 7.5 mph. Two of those and my calves cramp, so we started doing 220's at 7.5mph. I made 4 last time.
Dumbbell Clean & Press
Close hands pushups
Hangs from Pullup bar
Myotatic crunch (ball)
Situps (on bench)
Leg raises on bench
Tim Ferris curls & tricep extensions (10 second reps)
I chose different ones each time for muscle confusion. we have increased our reps and/or weight at all of them over time.