The P90X back workouts have a heavy emphasis on pullups. When you receive the DVD set, you will notice information about supplemental equipment. It is recommended you use the P90X pullup bar for a variety of different back exercises. The bar will add about $60 to the total cost of the program. However, there are alternatives that you could use to avoid having to buy it.
Alternative Pullup Bars
The pullup bar that P90X suggests is a high-quality product. It will install in most door frames without being permanent and it will not cause damage. However, there are alternative bars that can be purchased for much cheaper. They may not offer the variety of hand grip positions, but they still can be effective. The Perfect Pull-up and Iron gym are very similar and can provide the same workout for a fraction of the price of the P90X bar. The basic Iron Gym bar can be purchased for as little as $30.
As an alternative, P90X also suggests resistance bands. Beachbody.com sells a set for about $40. You can get similar results and save a few bucks in the process. There are even bands offered by other companies that may be even cheaper. Keep in mind, the bands will provide a different type of workout because the resistance becomes progressively harder as the bands stretch. In a pullup, your body weight is constant. To use the bands you need to have something secure that you can loop the band over which is high on a wall or ceiling. This may be a problem, depending on what room of your house you plan to work out in.
Skip the Pullup Parts of the Routine
P90X is based on circuit training and not all of the back exercises are pullups. If you have bands or weights you can complete the ground-based back exercises, skip the pullups and still get a decent workout. It's a good idea to fast forward though the pullup parts if you choose to do this so that you can keep the pace up and heart rate up. This may be a good way to start the routine initially and as you progress through you can then purchase the pullup bar later if you choose.
Rig up Your Own Pullup Bar
If you are handy, you can make your own pullup bar by simply using a thick pipe and two pipe support brackets to mount the bar in a doorway. Mount the bar as high as you can so that it is not in the way, and if there is room, mount it in front of the door stop so that the door will still close. Use a heavy gauge bracket and quality fasteners, preferably lag bolts, that are long enough to screw into the doorway studs. Be sure to test it thoroughly to make sure what you have fabricated will support your body weight and not cause damage to the doorway.