HERE ARE THE DO'S AND DON'TS OF WORKING OUT WHEN YOU'RE SORE...
Any time you perform an activity that requires your muscles to bear extra weight or perform in a different way, you're likely to experience muscle soreness or DOMS. That exercise causes micro-tears in your muscle fiber causing your body to jump into action to repair them. DOMS stands for Delayed Onset Muscle Soreness, and the name is quite fitting because the soreness usually occurs for 24-72 hrs.
You may be thinking "I've been sore walking out of the gym at times!" You're absolutely right. Sometimes you'll also experience acute muscle soreness immediately following strenuous activity. However, for the purpose of this discussion we'll focus on the delayed onset variety and how it affects future workouts.
DO plan exercise splits
Soreness is unavoidable, so don't let it stop the party. Instead, you should be planning accurate exercise splits which allow you to focus different areas of the body while allowing your muscles to recover. For example, you could plan upper body, lower body, back and ab days where you'll focus just those muscle groups. You'll only work each group every two to three days to allow for adequate recovery insuring that you're unlikely to exercise the same muscle groups while still sore.
It may look something like this:
DAY ONE: Legs
DAY TWO: Upper Body
DAY THREE: Back
DAY FOUR: Abs
DAY FIVE: Rest Day
DAY SIX: Legs
DAY SEVEN: Upper body
...and so on.
DO get a massage
DO keep a mental log of the duration
Typical DOMS can last anywhere from 24-72hrs. You should scrutinize any muscle soreness you feel beyond that duration as it may not be the normal post-workout muscle recovery. If you decide instead to workout through the soreness you may experience immediate muscle failure which will cut your workout short.
DO see a doctor
If your body doesn't seem to be recovering well post workout head straight to the doctor. You could be unknowingly nursing any number of sprains, strains or tears.
DON'T take pain meds
Pain is a signal, and you should listen to it. You know your body, and you know when things don't seem quite right. If you're experiencing DOMS, do not take pain medication before your workout because you're blocking a crucial signal when you should be most vigilant.
DON'T think soreness equals a good workout
Never think that a lack of soreness means you didn't push yourself hard enough. Did you get through your workout? Did the workout feel intense during? These are the questions you should be asking yourself.
DON'T stretch solely to prevent soreness
Stretch before your workout because it contributes to your overall athleticism and flexibility, not to alleviate soreness. Stretching hasn't been shown to reduce DOMS at all, and it may actually decrease your power and strength capabilities for certain exercises.