Which type of muscle fiber exhibits greater resistance to fatigue?

Type 1 muscle fibers, also known as slow-twitch fibers, exhibit a greater resistance to fatigue compared to other types of muscle fibers. This is primarily due to their high content of mitochondria, myoglobin, and capillaries, which support aerobic metabolism. These fibers are designed for endurance activities, such as long-distance running or cycling, where sustained energy output is required over an extended period.

The reliance on aerobic respiration allows Type 1 fibers to use oxygen efficiently to produce ATP, providing a steady supply of energy. Their slower contraction speed and ability to maintain prolonged activity without accumulating significant levels of lactic acid contribute to their fatigue resistance. In contrast, Type 2 fibers (which include fast-twitch fibers) are more suited for short bursts of high-intensity activity, leading to quicker fatigue because they rely more on anaerobic metabolism. Other fiber types mentioned are not typically classified in this way and do not align with the established classification of muscle fibers based on fatigue resistance.