Most bodybuilders, once they reach a certain stage in their training and development, shy away from bodyweight exercises. They assume these exercises have no value and you cannot build muscle. Most intermediate to advanced bodybuilders are using weight above their bodyweight on exercises for the major muscle groups. For this reason, they figure they cannot get enough resistance to make bodyweight exercises worthwhile. This is not entirely true.
While it is true that a strong bodybuilder could probably do a large number of push-ups in each set, there are exercises and variations that can be very effective for a bodybuilder. Changing the angle of exercises, raising them to get a greater range of motion, or altering the speed of the repetitions can all have an effect on the intensity of the exercise. Some exercises allow for the addition of weight to the body to increase resistance.
Push-ups are one of the first exercises that come to mind when thinking of bodyweight exercises. Push up bars that allow for a greater range of motion can make push-ups, once again, effective for the experienced bodybuilder. Placing the feet on a raised platform can increase overall resistance, and change the area of the pectorals trained, as well. Changing the width of the hand position can also change what part of the muscle, and what assistance muscles, get called into play. Slowing each repetition down, so the total repetition takes 6 to 12 seconds, can really burn deep into the muscle.
Pull-ups are another traditional bodyweight exercise. Resistance can be added to these by attaching weight to the body by using a weight vest, ankle weights, or a weighted belt. Changing the hand position on the bar can change what part of the back gets targeted, also. Slowing the reps down, just like the push-ups, can also increase the workload. For the more daring, and strong, lifter, one arm pull-ups might be an option to target one side and then the other.
Dips are another great bodyweight exercise for the upper body. Weight can be added to these just like pull-ups. Gironda-style dips are great for targeting the chest and adding a unique resistance to the exercise. These are done by leaning forward, placing the legs out in front of the body, and lowering yourself forward and downward, then pushing back up to the starting position. Using a wider or narrower grip during the exercise can also change the way the exercise works the body.
The lower body can be worked with bodyweight exercises, as well. One effective exercise, for even the experienced lifter, is the explosive squat jump. This is performed by placing your hands on your hips, keeping the back straight, and bending at the knees until your thighs are parallel to the floor. Then forcefully, and explosively, push upward to jump off the floor. Land and then, after settling, repeat again for the next repetition. Weight can be added to this exercise just like the pull-ups and dips, for added resistance.
Try adding each of these to their respective muscle group exercises (push-ups with chest, dips with chest or triceps, pull-ups with back, and squat jumps with legs) and watch the muscles develop. Adding a few sets of the exercise to the end of the workout will add an additional layer of training and help tear down additional muscle fibers to induce more growth. Bodyweight exercises do have value for any athlete, even the grizzled veterans who think they know better.