The Cori cycle is a metabolic pathway that helps the body manage energy during intense exercise. When muscles work hard, they produce lactic acid from glucose, which can lead to fatigue. The lactic acid is then transported to the liver, where it is converted back into glucose through a process called gluconeogenesis. This newly formed glucose can be sent back to the muscles for energy, allowing them to continue functioning efficiently. The Cori cycle is essential for maintaining energy levels and preventing the buildup of lactic acid, which can hinder performance during physical activities.