ELI5 Sore Muscles - Why the delay in soreness after a workout?

Why does it take 24 hours for muscles to start hurting after a workout? Why not straight away? We explain delayed onset muscle soreness (DOMS) like I'm 5. And while we're at it, what are muscle knots? How do I get them and get rid of them?   ... We explain like i'm five!   Thank you to the r/explainlikeimfive community, and specifically the following reddit users whose questions and responses formed the basis of this conversation: 400stars, peaceoutscout, crispturtle & chaveza94   To the ELI5 community that has supported us so far, thanks for all your feedback and comments. Send us an e-mail: [email protected]