Delayed onset muscle soreness (DOMS). It's that deep ache in your legs that makes it challenging to sit down without holding onto the arms of a chair, or the pain in your chest when you hug someone in the days following an intense workout.



The good news is, it means you did something in the gym that’ll help build muscle. The bad news is, you might need to endure the pain for a day or two.



In this blog post, I’ve outline what doesn’t work, what might work, and what does work to deal with sore muscles and speed recovery.



What Is Delayed Onset Muscle Soreness?



Delayed onset muscle soreness (DOMS) is the pain, stiffness, and slight swelling you feel in the hours or days following an intense exercise session.




DOMS is classified as a type I muscle strain injury and presents with tenderness or stiffness to palpation and/or movement."
Cheung K et al. Delayed Onset Muscle Soreness. 2012



It is usually triggered by:




Starting a new training program after a layoff or for the first time



Higher-rep or higher-volume training



Eccentric or ballistic training (weights, downhill running, plyometrics, etc.)



Any other intense physical activity you might not be accustomed to (golf, moving furniture, gardening, etc.)




The soreness hits you 12-36 hours after your training session or physical activity.



What causes delayed onset muscle soreness?



According to the most current research, there are six possible causes of delayed onset muscle soreness:




Lactic acid accumulation: Lactate accumulation creates the burning sensation you feel when completing dozens of squats or pushups. Most people feel sore following these types of workouts, which led researchers to believe lactate accumulation contributes to DOMS. However, concentric-only exercise can create significant lactic acid buildup but rarely causes DOMS. Also, you metabolize lactic acid within an hour following training, and DOMS doesn't even show up for many hours after that.



Muscle spasm: The muscle spasm theory suggests that your muscles go into a minor spasm following intense training. The microscopic contractions are small, but significant enough to trigger nerves and cause pain, which causes the muscles to spasm even more. Research on this theory is inconclusive.



Connective tissue damage: Connective tissue wraps your muscle fibers. According to this theory, muscle contraction stretches the connective tissue enough to cause microscopic injury, triggering the soreness. This theory is difficult to prove.



Muscle damage: The muscle damage theory is the most-accepted of the six opinions, but it probably isn’t the only factor causing muscle soreness. Following intense muscle contraction, components of muscle fibers get damaged. The damage causes an immune response and an increase in enzymes like creatine kinase (CK).



Inflammation: Inflammation plays a role in any injury in the body, even a minor and beneficial injury like workout-related muscle tissue damage. Proteolytic enzymes break down the damaged tissue, while other inflammatory-related compounds, including bradykinin, histamine, prostaglandins, monocytes, and neutrophils, play other roles. All these inflammatory compounds draw fluid into the muscle, causing inflammation.



Enzyme efflux: Following damage to the muscle cell, calcium escapes from the damaged sarcoplasmic reticulum, which activates proteases and phospholipases, or proteolytic enzymes. This theory suggests the proteolytic enzymes cause further damage to the area and stimulate pain-related nerves.




In reality, it’s probably a combination of all these theories and then some.



What Doesn’t Reduce Muscle Soreness



Why do I include what doesn’t work?



Like anything else in health and fitness, there are many myths about how to reduce muscle soreness. Though the following offer other health benefits, they don't reduce muscle soreness according to the research. 




Cryotherapy: When it comes specifically to reducing dela...