When reading this workout routine, you may think it to be simple and easy due to the short time frame it is performed in; however, I assure you that if you do this routine properly, your muscles will be burning, your heart will be pounding, and you will definitely be pushing the limits of your lactic acid threshold! To get the most out of this workout, it is essential to have a stopwatch or other timer to strictly keep the time constraints and to keep attempting to finish reps during the 20 seconds of work phases you will see. Also proper form is critical on all the exercises. Good luck!
Complete 32 intervals of 20 seconds of work followed by ten seconds of rest where the first 8 intervals are pull-ups, the second 8 are push-ups, the third 8 intervals are sit-ups, and finally, the last 8 intervals are squats. There is no rest between switching exercises.
Tailor this as you see fit. I do full extension overhand grip pull ups (Chin over the bar, elbows lock out at bottom) and when I get too fatigued to do full pull ups I switch to half pull ups or jumping pull ups. Pushups are chest to the ground elbows locked out at the top ( When these get too fatiguing I switch to knee push ups). Abdominals the first 2 rounds I do regular sit ups, next 2 rounds flutter kicks, next 2 rounds crunches with legs in air in seated position, last 2 rounds leg lifts. Squats down to 90 degrees and all the way up.