Chest to Bar Pullups
Whether you use a regular kip or butterfly, this movement requires effective use of your upper back muscles and not just your arm flexors. It is critical to be able to retract the shoulder blades in order to push the chest forward at the point of contact in this movement. This aspect of the movement can be difficult, especially under fatigue.
We can use some focused functional bodybuilding movements to help us strengthen the required motor pattern and muscle groups. Movements that recruit the upper back or minimize the involvement of the upper arm flexors are ideal. Here are some ideas to mix into your training:
Wide Grip Strict Pull Ups
Why: The wide grip hand placement makes the upper arm much less effective at applying force for the pull up and therefore relies more heavily on the lats and upper back. This will target those muscle groups specifically involved in pull the chest forward on your C2B pull ups.
How to: Perform them with a 2-3 second eccentric (lowering), and try to string reps together without pauses until you lose quality or cannot hit full range of motion. Weighing these or assisting the motion are both encouraged depending on your skill level. The goal is to hit full range with as wide a grip as you can comfortably get.
GHD Row (or Prone Row)
Why: The GHD row, or alternatively the Prone Row (laying flat face down on an elevated bench), with a wide pulling grip on the bar, should allow you to focus on pulling in a perfectly horizontal plane to target the rhomboids and other upper back muscles crucial to C2B pull ups. The GHD version is advanced and should only be performed if you can hold a Sorenson (bodyweight GHD plank) for 2:00. Otherwise perform these rows with your chest supported on a bench. Working up to a GHD row can be a goal as this movement will help to coordinate all the posterior chain muscles with your upper back, another skill that lends itself well to C2B pull ups.
How to: Perform these with a 2sec pause at the top of each rep in which you really focus on squeezing the upper back and pinching the shoulder blades together. Then lower in 2sec to make for a 21X2 tempo for 6-10reps. Perform 3-5 sets.
Lean Away Ring Pull Up
Why: All the magic of this movement comes in the eccentric. By leaning away dramatically from the top of the pull up rep and lowering slowly, you target the necessary C2B muscle groups and take them through a slow and long eccentric pull. That eccentric (or lowering phase) is where you will get a great stimulus for those muscles to get stronger and more efficient.
How to: Ideally, these are performed with a 3-5sec lowering phase. Pull up strict to the top, pause for 1sec, and then initiate the lowering with a lean away. The rep ranges will vary greatly on your upper body strength. For those who are beginning you can perform 1 rep at a time with a very slow lowering. Accumulate about 10-12 reps on your first go around. Work up to being able to string 3-5reps together at a time. This movement can also be weighted.