How long after a meal should you wait to workout? ADVERTISEMENT 960 viewsAugust 31, 2011 0 Gus0 August 31, 2011 0 Comments 11 Answers ActiveVotedNewestOldest 0 Aaron0 Posted 0 Comments It depends on the density of the meal. Typical whey protein shakes can be in and out of the stomach in as little as twenty minutes. Largely more dense meals take longer to digest. THe general rule is 2-3 hours for digestion. You are viewing 1 out of 11 answers, click here to view all answers. Register or Login