Any type of activity that places unaccustomed loads on muscle may lead to DOMS -- delayed onset muscle soreness.
It's different from acute soreness, which is pain that develops while doing the actual activity. Delayed soreness typically begins to develop 12-24 hours after the exercise has been performed and may produce the greatest pain 24-72 hours after you exercise.
Activities that cause DOMS include those when muscles are lengthened and force is applied. This is called eccentric muscle action. These movements include bicep curls when one lowers or extends the arm, or lengthening the leg muscle when one runs, jogs or walks for extended periods of time on a flat surfaces or hills. This usually occurs when one is not used to doing these activities on a regular basis. Post exercise muscle pain is not caused by the buildup of lactic acid in your muscles, as was once believed your body is actually making adaptations to better prepare your muscles to do that activity again. This temporary discomfort is a natural part of your body’s muscle rebuilding process.
How sore you become depends on the types of forces placed on the muscle. Running down a hill will place greater force on the muscle than walking down the same hill. The soreness that develops will probably be worse if you are running.
All people are susceptible to DOMS, even those who have been exercising for years. The severity of the soreness normally becomes less as your body adapts to your new workout. Just one bout of soreness-producing exercise actually develops a partial protective effect that reduces the chance of developing soreness in that same activity for weeks or months in the future.
Today, scientists know that DOMS is influenced by athletic conditioning and age. Younger athletes are susceptible because they haven't been conditioning long enough for the muscles to handle heavy and intense workouts. They do not have enough of an anti-inflammatory enzyme due to this lack of conditioning time. Older athletes are susceptible because of their age, shifting hormonal status and decreased recovery response. Older athletes have lower anti-inflammatory enzyme levels and their inflammatory response systems are less efficient. Research indicates that a good warm up before exercising will prepare your muscle to be more able to handle the activity and prevent DOMS.
Some believe that having DOMS is like a badge of honor. Just because you're not crippled the next day doesn't mean you didn't get a good work out in. Your should feel some soreness 24 hours to three days after your activity. If you try to do the same exercise and you cannot because you go immediately to muscle failure, you've done too much. There is also a genetic component to how sensitive we are to pain and soreness. If you have a low pain tolerance you will experience DOMS more acutely than someone who has a high pain tolerance when given the same training load. It's important to know your body's tolerance to pain before you do any exercising.
