Distance runner Paula Radcliffe has won dozens of long-distance races and held the women's world record for the marathon since 2003. Scientists, trainers, and athletes alike have wondered about the extent to which muscle structure and function contribute to success in athletes such as Radcliffe. What makes elite distance runners so good? Are their muscles somehow different from those of less successful athletes and non-athletes? Predict the effect of training for a marathon on the number of muscle cells in the gastrocnemius. Explain.

Verified step by step guidance

1. Understand the muscle structure: The gastrocnemius muscle is one of the primary muscles used in running, located in the calf. It is composed of both slow-twitch (Type I) and fast-twitch (Type II) muscle fibers.
2. Recognize the impact of endurance training: Training for a marathon primarily enhances the efficiency and endurance of muscle cells rather than increasing their number. Focus on how training affects muscle fiber type and function.
3. Consider muscle adaptation: With consistent endurance training, such as preparing for a marathon, the body adapts by enhancing the oxidative capacity of the muscle fibers. This includes increasing the number of mitochondria and capillaries in the muscle cells.
4. Discuss muscle fiber transformation: Prolonged endurance training can lead to a transformation of some fast-twitch fibers into more fatigue-resistant fibers, which are better suited for endurance activities.
5. Conclude the effect on muscle cells: While the total number of muscle cells (muscle hyperplasia) typically does not increase significantly, the changes within the muscle fibers themselves enhance their endurance capabilities, making them more efficient for long-distance running.