The "Chest & Back" routine in P90X consists mostly of various pushups and chinups, with three exercises that utilize free weights. You will need a chinup bar and a pair of weights to complete all of the exercises in the routine. The "Chest & Back" routine should be completed on the first day of weeks one to three and nine to 11.
Get into the standard pushup position and do as many pushups as you can for one minute. Remember to keep your back and abdominal muscles tight when doing a pushup. Lower your straight body almost to the floor, only a few inches above it. If you cannot do pushups for a full minute, do as many as you can and then hold the pushup position for the rest of the minute.
Wide Front Pullups
For this exercise, you need a chinup bar. Grasp the wide grips of the bar and pull yourself up until your chin passes the bar. Make sure that both of your arms are fully extended when you go into the bottom position. Do as many pullups as you can for one minute. If you cannot do pullups for a full minute, consider using a resistance band to make things easier. You can also use a chair to help lower the resistance.
Place both of your hands below your shoulders and keep your elbows and arms tight against the sides of your body. With this position, do pushups for one minute. If you cannot complete the full minute, maintain the position for as long as you can.
Reverse Grip Chinups
Grab the bar from the middle and with your palms facing your face. Lift yourself and repeat for a full minute. Again, if you cannot do this for a full minute, consider using a chair or resistance bands to make the exercise easier.
Wide Fly Pushups
Get into the normal pushup position and extend your hands three inches farther out from that position. Do pushups in this position for a full minute. If you cannot, simply hold this position for a full minute.
Closed Grip Overhand Pullups
Grab the bar with a narrow grip and your palms facing away from your face. Again, do pullups for a full minute. If you can't, use resistance bands or a chair.
Decline pushups are simply normal pushups but with your feet elevated on an object, preferably something that is 4 to 6 inches high. The taller the object is, the more difficult the pushups will become. Repeat this pushup for a one minute.
Heavy Pants and Lawnmowers
Heavy pants and lawnmowers are two of the three exercises that require free weights. For the heavy pants exercise, place one foot forward and bend your knees. Bend your body at the waist and keep your back flat. Lift the weights from the front foot to your waist. Repeat for 12 to 15 reps. For the lawnmowers, get into a lunge position and rest one elbow on your knee. With the other hand, lift the weights from the floor to your waist. Switch sides and repeat this exercise for 12 to 15 reps.
Diamond Pushups and Back Flys
For the diamond pushups, place both of your hands on the floor in a diamond shape. Do pushups in this position for one minute. If you can't, simply hold the position for as long as you can. The back flys are the other exercise involving weights. Stand on a chair and hold weights at arms' length with your wrists inward. Lift the weights toward the ceiling. Repeat this exercise for 15 repetitions.
This is the most difficult pushup in the routine. Begin in a downward dog position and move into the upward dog position, almost as if you were trying to get under a fence. Reverse the exercise, going from upward dog to downward dog to complete one repetition. Perform as many repetitions as you can for a full minute.