For the perfect exercise for building upper-body muscles, look no further than the classic pullup. This simple though often demanding exercise builds muscle along your shoulders and back as well as your arms and abdominal area. If you don’t feel like purchasing a pullup kit from the store but would rather construct your own, it's a fairly easy DIY project, requiring only simple tools and materials.
Drill a hole into the ends (both of them) of all four 10-foot, 6-by-2-inch wooden planks. Drill around 2 inches from the end of the plank. The hole on one side of each plank will fit a heavy duty metal pipe and the holes on the other side will fit a machine bolt eye hook.
Run a metal pipe—heavy-duty, of around 4 feet in length—through the top holes of each of the four planks, then use pipe caps to cap both ends of the pipe. You should now have a metal pipe running through all four planks.
Screw the machine-bolt eye hooks into the bottom holes. The hooks on the two left-most planks must face one another, while the hooks on the right-most planks must face each other.
Attach four carabiners, one to go with each eye hook. Attach the light chain ends to the carabiners, with the first chain attached to the two left planks and the second chain attached to the two right planks.
Stand up your pullup bar device, then slide the planks apart, with the two on the left all the way left and the two on the right all the way right. Extend the bottom of the planks so that the chains are tight.