What are White Muscles?

White muscles are also known as fast-twitch muscles or type II fibres. Their diameter is large. They are designed for intense bursts of activity. These muscles are responsible for generating quick and powerful movements. They have a low content of myoglobin and cytochrome. They have fewer mitochondria compared to red muscles, which limits their aerobic capacity. However, they compensate for this by relying on anaerobic metabolism, which provides rapid bursts of energy. White muscles are predominantly involved in activities that require explosive strength and speed, such as sprinting, weightlifting, and high-intensity sports.

Characteristics of White Muscles

White Muscles have the following characteristics:

1. White muscles have a limited blood supply and lower capillary density. This restricts the amount of oxygen and nutrients available during activity, leading to a higher reliance on anaerobic metabolism.
2. White muscles have a lower capillary density compared to red muscles.
3. They fatigue more quickly due to their dependence on anaerobic metabolism, which produces lactic acid as a byproduct. The accumulation of lactic acid can lead to muscle fatigue and a decrease in performance.
4. White muscles are helpful in short bursts of intense activity but they are less suitable for prolonged exertion. They contract rapidly, generating quick and forceful movements as they have more Sarcoplasmic Reticulum and calcium ions which helps in rapid contractions.
5. These muscles are found in extraocular muscles (muscles of the eyeball), muscles in limbs, flight muscles of perching birds, and muscles of chicken breasts.

Difference between Red and White Muscles: Red and White Muscles are different types of muscles based on their functions and characteristics. The main differences between red and white muscles lie in their colour, oxygen supply, contraction speed, fatigue resistance, capillary density, and structure. Red muscles are slow-twitch fibres, have a higher myoglobin content, abundant mitochondria, a rich blood supply, and are involved in endurance activities. On the other hand, white muscles are fast-twitch fibres, have less myoglobin content, fewer mitochondria, limited blood supply, and are designed for intense bursts of activity. Muscles play a crucial role in our bodies, enabling movement and providing support.  In this article, we will cover the differences between red and white muscle in detail.