No pain, no growth. If you don't feel any pain after a workout, you're not making progress. This is one of those concepts that has been floating around for years, and you can still find quotes online from people who believe that if they don't feel any pain, then the workout was a waste. Many people chase muscle soreness because it's thought to be related to growth. So the goal of the workout is pain. But the goal should be progress and growth.   What is delayed onset muscle soreness (DOMS) or muscle soreness? As the name suggests, we are talking about painful sensations in the muscles after training. It often happens to beginners and often occurs after various types of eccentric loads.   By eccentric loading, I mean a contraction in which the muscle being worked lengthens under load. Lowering a weight is one option, but there are others. For example, hill running is known to cause a lot of muscle soreness, and that's because the muscles lengthen under heavy load gracify.co.uk/which-material-is-best-for-yoga-mat/.   And the word “delayed onset” is related to the fact that DOMS usually occurs 24 hours after the workout and peaks at 36 hours. Despite the rather old (and still popular) idea that the cause of pain is lactic acid that accumulates in the muscles during training; the fact that DOMS occurs a long time after the workout clearly shows that lactic acid has nothing to do with it - it is absorbed within 30 minutes after the workout. It can have nothing to do with what happens 36 hours later. The lactic acid myth was created in the early 90s and I am amazed that it has not gone out of fashion.   Muscle biopsies after eccentric exercise (often hill running, or a stationary bike designed to stress overstretched muscles, or a crazy 10 sets of 10 eccentric reps) often show microtrauma to the muscle fibers. So eccentric exercise causes DOMS, which means growth. So DOMS is what you want, right? Nope.   Because, if you think about it, not only is muscle soreness not a sign of future growth, but rather the opposite is true.   Here are four things to think about: Typically, muscle soreness is worst at the beginning of a training cycle, especially when learning new exercises, and gains are usually noticeable towards the end of the cycle, when muscle soreness is no longer present. Some muscles, such as the deltoids, rarely hurt, but grow wonderfully. No muscle soreness required. Those who train infrequently, say one muscle group once a week, often report horrific muscle soreness. But few of them can boast of good results in terms of growth. Those who train more frequently (hitting each muscle group 2-3 times a week) often experience LESS muscle soreness and MORE growth. All of the above essentially means that not only is muscle soreness not related to growth, but in most cases, real hypertrophy occurs in conditions of less muscle soreness. Yes, these are just observations and life experience, but these are very, very common observations. By and large, muscle soreness is not related to growth.   Where does muscle soreness come from? After it became clear that lactic acid was not the culprit, research showed that DOMS may be directly related to muscle trauma. And eccentric exercises are known to cause microtrauma to muscles. Maybe it is the microtrauma, maybe it is not.   Under the microscope, cell ruptures and other signs of injury became clearly visible. Often, new marathon runners experience terrible muscle soreness, which requires up to 6 weeks to fully recover (many say that after their first marathon, they have to walk down the stairs backwards because their leg muscles can't hold up). So, if you want growth, run a marathon and rest for 6 weeks until the pain goes away. Just kidding.   The idea that DOMS is related to microtrauma has been questioned in recent years and reinterpreted as "reconstruction." In reality, it is more of a semantic issue. And the fact that DOMS can be related to muscle reconstruction still suggests growth. But, according to the real-world situation discussed above, there is no clear relationship between growth and DOMS.   And while most research suggests that a combination of concentric and eccentric loading (lifting and lowering a weight) is best for growth, some studies suggest that concentric-only exercises can produce the same effect if the volume of work is the same.   Also, researchers don't usually look at growth per se, but rather at something like cytokine release during inflammatory responses, macrophage infiltration, etc. All of these parameters also vary, but generally seem to be related to the degree of injury.   While some microtrauma/inflammation may be necessary to stimulate remodeling (not always associated with DOMS, by the way; see the 4-point list above), too much inflammation, requiring more than a week to recover, can actually lead to muscle fiber death (Skeletal Muscle Necrosis, great name for a death metal band). A little is good, more is better, and too much is really bad. By chasing DOMS so severe that it takes a week to recover, you are doing yourself more harm than good. In an extreme case, see CrossFit, where the microtrauma to the muscle can be so severe that it sets off a chain reaction that leads to rhabdomyolysis.   Yes, it's rare, but it means that too much damage is worse, not better. There's a theory called the inverted U-shaped curve. Too little is bad, too much is bad, and somewhere in the middle is just right.   Other problems with muscle soreness By the way, have you ever wondered how scientists measure pain in people? Basically, it's done something like this: a piece of muscle tissue is cut out of someone. Then the subject is subjected to an extremely tough workout. Usually, it's running downhill, or pedaling backwards on a special exercise bike that literally tears the muscles apart, and 10 sets of 10 reps. Then another piece of muscle tissue is cut out and compared to the first piece.   What do you mean they cut out a piece of muscle tissue? Yes, it's called a muscle biopsy and don't Google it if you have a weak stomach. But you have to do it at least twice, and because of the lack of control samples, it has been suggested that what is perceived as microtrauma is the result of the biopsy itself. That is, cutting out several pieces from the same muscle creates the observed pattern of microtrauma. You can check this yourself, take a pair of scissors, drink something strong and… no, you better not do that.   Final Words In general, in real life conditions, muscle soreness is not only not related to growth, but rather the opposite. Those who experience muscle soreness less often due to more regular and frequent training usually grow better than those who "injure" their muscles once a week (instead of reconstruction, possibly causing muscle fibers to die off) and get tons of muscle soreness.   Some people have muscle soreness, others don't, there can be significant individual differences in this parameter, and I can't say what causes them. But chasing muscle soreness for the sake of muscle soreness is masochistic stupidity. The goal of training is progress, not fatigue and pain. I can kill those who want it in the gym - I mean, make them leave limping and completely exhausted, and then suffer for a week.   But this rarely improves the result. It just leads to pain and fatigue. You might as well hit yourself with a stick and wait for your muscles to grow.