You need a little soreness. It means your adapting, getting stronger. But too much means you’re risking injury or could be overtraining. Here’s why:
The first few weeks of training are brutal on the body. Even for a veteran CrossFitter, taking off a week and coming back can be just as cruel. Your legs and back hurt, and walking up stairs or even sitting down sucks! As your body changes and adapts, you’re going to be sore. I want you to know that this is entirely normal and all part of the process. DO NOT let these byproducts of adaptation take a toll on your motivation.
While we can’t eliminate body soreness, we CAN manage your expectations. It’s important to understand the process and not to confuse soreness with being hurt. Should you train if your muscles are sore? Some fitness experts who would tell you a flat “no.” The real answer is: it all depends on YOU. You are the owner of your body, and you need to make that call for yourself. Mild to moderate DOMS (Delayed Onset Muscle Soreness) is unlikely to be a problem. However, if you have severe soreness in a particular muscle group, I would suggest that you provide that body part with some relative rest. An example: if you have severe soreness in your legs from squatting during Cindy, then you should avoid attacking a workout with heavy back squats the next day (a very similar movement pattern). I see less of a problem if you run on those sore legs, as the movement is quite different from what caused the damage. Just be aware that your run performance will probably suffer in comparison to running on fresh legs.
Note that chronic muscle soreness that seems to linger for longer than usual may be a sign of over-training, or under-recovery, whichever way you choose to look at it. If you are feeling unusually unenthusiastic about your training, and you are noticing chronic muscle soreness, you would be well advised to listen to your body and take appropriate rest until your body and mind are back in the game.
Remember that muscle damage and soreness are essential and probably unavoidable pre-requisites for optimal muscular adaptation. If you have an aversion to feeling sore, you can either stop doing CrossFit (not an option for most!) or reframe your attitude. How? Try any or all of the following: