One of the advantages of carbohydrate over fat is the ability to support the production of lactate. This is so important that carbohydrate is physiologically essential to red blood cells and certain brain cells known as astrocytes. For the same reason, it plays an important role in supporting the energy requirements of the lens and cornea, kidney medulla, and testes, and supports the quick boosts of peak energy needed during stressful situations that include high-intensity exercise. The biochemical role of lactate is to rescue NAD+ during times when NAD+ becomes limiting for glycolysis and glycolysis becomes a meaningful source of ATP. Through the Cori cycle, lactate can extract energy from the liver’s supply of ATP and deliver it to other tissues such as skeletal muscle in the form of glucose. This lesson fleshes out the physiological and biochemical roles of lactate and serves as a foundation for the next lesson, which explores the role of carbohydrate in supporting sports performance. Watch the full lesson at chrismasterjohnphd.com/mwm/2/17 Sign up for MWM Pro for early access to content, enhanced keyword searching, self-pacing tools, downloadable audio and transcripts, a rich array of hyperlinked further reading suggestions, and a community with a forum for each lesson.