The barbell complex is a great way to train your entire body in one go! The reps are high to get your cardiovascular system working, and the movements are heavy and complex to get your muscular system moving. Your whole body is being put through the wringer!
You'll have to go through 5 reps of power cleans, front squats, back squats, and push presses before you're allowed to rest. Remember to choose your weight based on your weakest lift, which is likely your push press.
Don't forget to write down your push press weight, your circuit times, what weights you used, and how you felt after finishing the workout.