Q & A: Sore?

Q: What causes muscle soreness and how is it best relieved?

A: There are two types of exercise-related muscle soreness. Immediate muscle soreness quickly dissipates and is the pain you feel during, or immediately after, exercise. Delayed muscle soreness signals a natural adaptive process that the body initiates following intense exercise. This type of muscle soreness manifests itself 24 to 48 hours after the exercise session and spontaneously decreases after 72 hours.

Numerous studies have been conducted to determine the cause of delayed muscle soreness. The most current consensus attributes this condition to microscopic tears in the muscle and surrounding connective tissue following eccentric exercise. A muscle contracts eccentrically when it lengthens under tension during exercise. For example, during a biceps curl, the biceps muscle shortens during the concentric lifting phase and lengthens during the eccentric lowering phase. Eccentric contractions also occur during aerobic activity, such as downhill running, in which the quadriceps muscle repeatedly lengthens against gravity to lower the center of mass and aid in shock absorption.

Exercisers who experience delayed muscle soreness include conditioned individuals who increase the intensity, frequency or duration of their workouts, or participate in an activity with which they are unfamiliar. Beginning exercisers, or those who have undergone a significant lapse in training, frequently experience soreness when starting or re-engaging in an exercise regimen.

Studies attempting to identify the best methods to alleviate delayed muscle soreness are almost as abundant as the number of studies conducted to determine its cause. Cryotherapy (the topical application of ice), massage, stretching and the use of nonsteroidal, anti-inflammatory drugs (NSAIDs), among other less conventional approaches, have been evaluated to determine if they can prevent or effectively treat delayed muscle soreness. To date, a therapy that consistently relieves delayed muscle soreness has yet to be identified. On the other hand, a few of the aforementioned therapies may have a mild positive impact if initiated immediately after intense or unusual exercise.

Once an individual has experienced delayed muscle soreness at a specific exercise intensity, he or she shouldn't encounter that sensation again until the intensity level is increased. This is because delayed muscle soreness has been shown to produce a rapid adaptation response, which means that the muscles adapt to a given exercise intensity level. Until (or unless) the exercise intensity level is changed, soreness won't occur. This factor is the basis for the most widely recommended approach to preventing delayed muscle soreness: gradual progression and conservative increases in intensity, frequency and duration. Preliminary light exercise may prevent the onset of soreness following a heavy eccentric-exercise workout. Beginners should exercise with light weights, two to three times per week for one to two months, then gradually increase the intensity of their workouts. Conditioned exercisers who want to try a new workout or activity also should begin gradually, taking care not to be overzealous in how hard they exert themselves- particularly until their bodies adapt to the demands imposed upon them.

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Source: Dr. Cedric X. Bryant, ACE's Chief Science Officer; ACE FitnessMatters, Jan/Feb 2007.

The Buzz: BMI

Some of my clients have asked me my opinion about BMI, or Body Mass Index. I don't mention it often or use it to measure their progress, but it's still making headlines in the news and magazines, nonetheless.

Fitness Matters, the American Council on Exercise's professional journal, does a great job of
describing the limitations of using BMI in its May / June issue.

BMI has several significant drawbacks. It can give a skewed result for some individuals and subgroups of the population. Jay Hoffman, a professor of health and exercise science at the College of New Jersey, says that BMI's main drawback is that "it just indexes height versus weight and doesn't take into account body composition."

Bodybuilders and elite athletes end up with a high BMI score because of the extra weight associated with muscle. So do fit civilians. (The article's author, Jim Gerard notes that while he is) hardly a body builder, but (he) work(s) out every day and at 6'2" and 210 pounds, (he has) a BMI result that puts (him) in the "overweight" category despite the fact that he has a 34" waist and a flat stomach. Conversely, taller people carrying a lot of fat may have a body mass index score that falls within the acceptable range.
BMI can also skew results in the opposite direction, as it does in the elderly, who tend to have scores that underestimate their excess weight or obesity because they have much less muscle than the average person.
Miller adds that BMI is not accurate when measuring the body composition of children or some small-boned women who, despite being petite, may have a small bone and muscle mass and a high percentage of body fat.
Another limitation of BMI is that it doesn't address the location of one's body fat, which is arguably a more telling indicator of overall disease risk. Abdominal fat in particular is linked o heart disease, poor lipid profiles and type 2 diabetes. And it's more likely to lead to changes in hormone levels that cause inflamed and eventually clogged arteries. Miller says, "The theory is that abdominal fat is more mobile and that it enters the circulation more readily to form arterial plaques."
Therefore, it's quite possible to have an acceptable BMI while carrying a potentially dangerous spare tire. And certain groups of people--those from Japan and south Asia, for example--that tend to stay relatively slender can still have an increased risk of heart disease from storing unhealthy amounts of abdominal fat.

The Buzz: Omega-3s

Omega-3s have been all over the health media lately. You can't pick up a magazine without reading about this miracle nutrient. Here's what Men's Health (May issue) has to say:

To drastically reduce your risk of future health problems, you need 3.5 grams of omega-3 fatty acids daily, according to scientists at the National Institutes of Health. The researchers made this determination when they calculated that 40% of mortality from heart disease and 95% of depression could be attributed to deficiencies in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the omega-3 fatty acids primarily found in seafood. These healthy fats reduce the inflammation associated with heart disease and may also cultivate the production of serotonin and dopamine, "feel good" neurotransmitters that can reliever and prevent depression, say study author Joseph Hibbein, M.D.

The American Council of Exercise notes that the best fish sources are salmon, tuna, herring, mackerel, sardines, and anchovies. Other food sources of omega-3s include soybeans and other soy products, canola oil, and flaxseed.