What type of exercise predominantly uses Type I muscle fibers?

Type I muscle fibers, also known as slow-twitch fibers, are primarily used during prolonged, endurance activities. These fibers are highly efficient at using oxygen to generate ATP, the energy required for sustained muscle contractions, which makes them ideal for activities that require endurance over a long duration.

Long-distance running is characterized by its reliance on aerobic energy production, which aligns perfectly with the properties of Type I fibers. They are built for stamina rather than strength or speed and can sustain activity over extended periods without fatigue. This makes long-distance running the perfect example of an exercise that predominantly utilizes Type I muscle fibers.

Other activities such as sprinting, weightlifting, and high-intensity interval training primarily involve Type II muscle fibers, which are geared more toward explosive strength and power. These activities demand quick bursts of energy and are not supported by the slow-twitch mechanism that Type I fibers provide.