Like any muscle in the body, the latissimus dorsi is made up of individual muscle fibers and it's rare that an individual muscle fiber runs the entire length of the muscle. Muscles are actually composed of one- to four-inch segments, and pull-ups (completed with an overhand grip) will not activate every muscle fiber.
To rectify this problem, it's crucial to occasionally change your grip to underhand chin-ups. The change in grip will slightly change the pull of the muscle, stimulating the unused muscle fibers, forcing them to grow. This variety will allow for strengthening and sculpting of the entire latissimus dorsi.
Target Muscles: latissimus dorsi
Set Up: Grasp a chin-up bar with a narrow, underhand grip.
Action: Keeping your shoulders back and down, pull yourself up towards the bar. Hold for a second, lower and repeat.
Here are some tips:
- Use an underhand grip (palms facing you).
- Keep your elbows tight to your body, so they remain in line with your shoulders.
- Have someone spot you under your knees or try a counter-balance machine to decrease the intensity of this exercise.
- Lift your chin over the bar at the top of the movement.
- Allow your arms to straighten fully at the bottom of the movement for a full range of motion, but do not lock your elbows.
- Keep your shoulders engaged throughout the set to maximize results and decrease your risk of injury.