What Makes Muscles Get Tired

Iris Fennimore

A boy sprints until his legs turn to jelly, then learns why his muscles feel like they're full of buzzing bees. Iris Fennimore explains the real science of fatigue using race tracks, cluttered desks, and dancing calcium so kids aged seven to ten can follow every step. Duncan Winslow reads with the steady patience of a favorite teacher, pausing just long enough for a young listener to picture oxygen's long journey from lungs to biceps. Perfect for children who ask "why" after every soccer practice.