Exercise physiologists refer to the gradually increasing muscle discomfort or soreness that occurs after physical activity as delayed onset muscle soreness (DOMS). Delayed onset muscle soreness occurs when the muscle is performing an eccentric or a lengthening contraction. DOMS usually kicks in 12 to 24 hours after a tough workout and peaks between 24 to 72 hours. Muscle discomfort is simply a symptom of using your muscles and placing stresses on them that are leading to adaptations to make them stronger and better able to perform the task the next time.
The mild muscle strain injury creates microscopic damage to the muscle fibers. Scientists believe this damage, coupled with the inflammation that accompanies these tears, causes the pain. It can happen when you bump up your workout intensity, frequency, or length, or when you try a new activity.
The good news is that normal muscle soreness is a sign that you’re getting stronger and is nothing to be alarmed about. During exercise, you stress your muscles, and the fibers begin to break down. As the fibers repair themselves, they become larger and stronger than they were before.
Mild to moderate muscle soreness is common and generally harmless. On the other hand, severe muscle soreness can be damaging and dangerous. It’s important to know the difference between reasonable muscle soreness caused by exercise, and pain due to overuse or muscle injury.
How much pain is too much? If, the pain you’re experiencing prevents you from carrying out daily activities associated with living or working, then the exercise was too much. If the discomfort lasts for more than 72 hours, then the exercise was too much.
How can you tell if your soreness is the normal kind of soreness? If the pain begins during or immediately after the exercise, it is not normal. Pain that occurs during an exercise is a sign that there is a problem with the exercise. This type of pain should be seen as a signal from your body to stop the activity before serious joint or muscle damage occurs.
In severe cases, the muscles can break down so much that you can become very ill and cause damage to your kidneys. Seek medical attention immediately if you experience any of the following after a workout or activity that causes muscle soreness:
- Severe unbearable pain
- Severely swollen limbs
- Loss of joint range of motion due to severe swelling
- Dark colored urine or decreased production of urine