Post-workout soreness, also known as delayed onset muscle soreness (DOMS), is a common phenomenon experienced by athletes and fitness enthusiasts. It is characterized by muscle pain and stiffness that usually occurs 12 to 24 hours after exercise. The two crossword solutions for this term are ACHE (4 letters) and ACHES (5 letters). ACHE is a noun that means a dull, continuous pain, while ACHES is a verb that means to experience a dull, continuous pain.