Try this total body workout in 16 minutes...if you can

This workout is not for the just-off-the-couch exerciser. If you do attempt this workout, respect it and make sure to give a 100% effort. Your first and last set should not differ by more than 3-4 repetitions. This is not very complicated so don't make it! If you cannot perform pullups, you will need to put another exercise in there, possibly pull-downs on a lat machine. The pull-up is the only exercise where it is understandable to fall way short on repetitions towards the end. At my peak, I could perform 10 sets of 10 repetitions of pull-ups with about 90 seocnds rest between sets. However, with only a 10 seocnd rest, your pull-up numbers will drop dramatically. You will be soaking wet and panting when finished, I always am. Good luck and train hard. Thank Tabata for this one.

Simple 16 minute fitness based workout

You do as many pull-ups (or dumbell curls, dumbell presses) as you can in 20 seconds, rest 10 seconds, then again do as many pull-ups as you can in 20 seconds, rest 10 seconds, and so on for 8 repetitions of doing 20 seconds of pull-ups followed by 10 seconds rest. Those 8 repetitions should take a total of 4 minutes.

Without any further rest than the 10 seconds after the eighth 20 seconds of pull-ups, you then start on push-ups - again it is 8 repetitions of as many push-ups as you can in 20 seconds, followed by 10 seconds rest. The 8 repetitions of 20 seconds push-ups, 10 seconds rest takes 4 minutes.

Then you do 8 repetitions of 20 seconds of sit-ups, 10 seconds rest, and another 4 minutes have gone by.

Finally, you are on to squats, and (you've guessed it!) it's as many as you can do in 20 seconds, 10 seconds rest and repeat until you've done 8 lots of 20 seconds squats, 10 seconds rest.

*If you do not have the capacity to do pull-ups just do the other 3. If that is too easy, do it twice.