Although the lower body is often neglected by the all-show-no-go, spray-tan types; those looking to build functional strength and a no-nonsense physique to match know that a powerful pyramid has a strong base. Building the base of your pyramid can be done at home, an office cubicle, a jail cell or in line at the DMV.

Mike Tyson came back to boxing from his three-year stint in a correctional facility bigger and broader. Along with a more muscled-up upper body, Tyson filled out his trademark black trunks like never before.

Word on the street is to develop these tree trunks, Tyson’s leg workout during his stint in the big house was the following:

Tyson Squat Workout

1. Start with 10 cards and line them up about 3 inches apart.

2. Squat and pick up the first card, then move to the next card and place the first card on top of the second card.

3. After which, you squat twice more to pick up each card individually, before moving to the third card.

4. Walk to the third card and squat twice to stack each card, then squat three times to pick up each card before carrying the cards to the fourth card, and proceeding with the pattern.

5. You will continue this pattern of individually stacking and picking up the cards until you move through all 10 cards in the line.

At that point, you will have completed 100 squats.

Here is the Jailhouse Strong challenge to you. Do this complete sequence three times, rest two minutes between sets. Complete each set in four minutes and you are physically fit. Do it in three minutes and the warden will call you sir.

Looking for another brutal challenge? Test your toughness with the 8-week Rock Hard Challenge.