Which type of exercise most often utilizes slow twitch muscles?

Marathon running primarily engages slow twitch muscle fibers, which are also known as Type I fibers. These fibers are designed for endurance activities and are highly efficient at using oxygen to generate ATP through aerobic metabolism. Slow twitch muscles are characterized by their ability to sustain prolonged periods of low to moderate intensity activity, making them ideal for endurance sports like marathon running.

In contrast, activities like sprint running, heavy weight lifting, and powerlifting emphasize fast twitch muscle fibers. Fast twitch fibers (Type II) are designed for explosive and powerful movements, allowing for quick bursts of energy but not for sustained efforts. Therefore, marathon running stands out as the exercise type that most commonly utilizes slow twitch muscle fibers, making it the correct choice.