Shen Ningning died of exhaustion after being dared to run a marathon. She transmigrated into a savage, unfamiliar world where humans struggle to survive among beasts. Before she could despair, she discovered she was bound to the Peak Body Survival System.The system believes survival is nothing more than physical training. Hunting, fleeing, gathering food, and even fear are all treated as endurance tasks, with failure punished mercilessly. Trapped in a dangerous world and forced to follow the system’s rules, Shen Ningning can only struggle to survive one day at a time.Her situation worsens when a powerful snake beastman claims her as his mate and refuses to leave her side. As danger closes in from both the wildlands and the system itself, Shen Ningning must find a way to live in a world that demands strength—whether she is ready or not.