Flexibility is an essential component of physical fitness. The most common technique used to enhance muscle flexibility is stretching. Even though there is a great amount of evidence showing the benefits of chronic stretching on flexibility, it remains unclear whether such increase in flexibility can affect muscle performance (MP). Most of the studies in this field have concentrated in analyzing the acute effects of stretching on muscle strength. However, the literature is scarce with regard to chronic effects of stretching on MP. The possible mechanisms involved in flexibility enhancement following chronic stretching give an indicative that MP might benefit from adequate flexibility. A decrease in muscle-tendon unit (MTU) stiffness seems to be a key aspect for an increase in performance since it might improve the energy storage capacity within the MTU during activities involving stretch-shortening cycle. In theory, it sounds reasonable, but in practice, the relationship between decreased MTU stiffness and increased performance still needs to be better elucidated. Hence, the purpose of the present clinical commentary is to discuss how increased flexibility provided by chronic stretching might affect MP.