Yes, chicken breast is a muscle, specifically the pectoralis major muscle of the chicken.
Chicken breast is commonly consumed and studied due to its relatively homogenous structure. This means the muscle fibers are generally similar, making it a suitable model for muscle protein research. While typically considered a white muscle, studies have shown some variation in fiber structure within the chicken breast muscle itself, particularly in the M-region structures of different fibers. However, fundamentally, chicken breast is muscle tissue.
