Right before or after training, rapidly digesting whey protein helps start recovery, a process that can take up to 48 hours. Between meals and before bed, when nutritional support wont be available for a while, casein protein can help provide longer lasting amino acid support. Casein proteins are pH sensitive and gel in the acidic environment of the stomach. As a result, it can take longer for caseins to be broken-down into their amino acid subcomponents than whey and other proteins. Because of their unique slow-digesting qualities, caseins are described as anti-catabolic or muscle-protecting proteins.