How is friction good and bad for runners?

Friction is beneficial for runners as it provides the necessary grip between their shoes and the ground, allowing for better traction and stability while running, which helps prevent slips and falls. However, excessive friction can lead to negative effects, such as blisters and skin irritation on the feet, potentially causing discomfort and impacting performance. Balancing the right amount of friction through appropriate footwear and running surfaces is essential for optimal running experience.