An untrained military cadet seeks to reduce fatigue during a prolonged rucksack march. Which muscle fiber type should be the primary focus of training?

Focusing on Type I muscle fibers is essential for an untrained military cadet aiming to reduce fatigue during a prolonged rucksack march. Type I fibers, also known as slow-twitch fibers, are highly efficient at using oxygen to generate energy for extended periods. They are particularly resistant to fatigue, making them well-suited for endurance activities such as prolonged marching.

Training that emphasizes Type I fibers will enhance aerobic capacity, improve endurance, and increase the efficiency of energy production. These adaptations will allow the cadet to sustain performance over the duration of the march, effectively reducing the perception of fatigue and improving overall stamina.

While Type IIa fibers, which are more associated with anaerobic work and have a mix of both aerobic and anaerobic capabilities, can also aid in performance, they are not as crucial for endurance activities as Type I fibers. Type IIx fibers are geared toward short bursts of power and speed, making them less applicable to a long-distance march where endurance is the priority. The mention of Type III is inaccurate, as this classification does not pertain to muscle fibers typically discussed in terms of endurance training. Therefore, prioritizing training that develops Type I muscle fibers aligns perfectly with the goal of reducing fatigue in an endurance setting.