Do a Tabata! A Tabata workout generally lasts between 16 and 20 minutes. Pick 4 or 5 moves, for example; pushups, situps, jump squats. Each move takes 4 minutes. Do each move as many times (with good form) as you can for 20 seconds, rest 10 seconds, repeat 7 more times. If you keep records of how many reps you can do, you can see yourself gradually getting stronger!