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Sidestepping postexercise soreness

When you finally get motivated to rearrange the furniture in the den or take that high-intensity step aerobics class, you may notice something besides a sense of accomplishment at the end of the day: sore, achy muscles. Postexercise stiffness is usually a sign that your body wasn’t properly prepared to start and finish intense physical activity—and that includes shoveling the driveway, ice skating in the park and hanging holiday lights. Fortunately, you can avoid sore muscles by using some exercise smarts.

Why it hurts

Muscles hurt after a period of intense activity because lactic acid builds up near the muscle area. During an intense aerobics class, for example, your body may not be able to get the oxygen it needs fast enough to break down the glucose it uses for fuel. Without oxygen, the glucose breaks down into lactic acid and huddles around the working muscle, constricting blood flow and increasing muscle fatigue. End result: pain.

Sometimes soreness appears immediately after a workout; other times it comes on 24 to 48 hours after you’ve exercised.

Preventing the pain

The key to preventing lactic acid from piling up is to train your body to use oxygen efficiently. That involves getting your body used to working hard. A five-minute aerobic warm-up, like walking or cycling, will boost heart rate and circulation. Make sure you stretch for five to 10 minutes. Stretching not only helps prevent injuries but also warns your muscles that they will be put to the test. Avoid bouncy movements during exercise, because they will increase the amount of lactic acid that builds up in your muscles.

When your workout is over, cool down and stretch again. Cooling down relaxes tired muscles and helps them get rid of lactic acid. Walking, for example, helps transport lactic acid to the liver, where it can be broken down.

One way to prevent delayed soreness is to rest the day after your exercise session. Jumping right back into your routine could wear out tired muscles, increasing the chance of injury.