Current muscle soreness treatments vary in approach--and effectiveness.

delayed onset muscle soreness (DOMS) is an acute inflammatory condition that occurs in athletes most often at the onset of a regimen, as in spring training. Muscle discomfort peaks 24 to 48 hours after exercise and is characterized by a decrease in range of motion, shock attenuation and peak torque (maximum strength). The posited causes include inflammation and connective or muscle tissue damage.

Though exercise is an effective analgesic in the short-term relief of DOMS, there may be an increased risk of injury with a premature return to vigorous activity. And since the pain-alleviating effect of exercise is temporary, there is currently a need for the discovery of treatments that restore maximal muscle function and alleviate DOMS-associated discomfort.

While several recent studies have looked at various promising treatments for DOMS, four of these treatments proved considerably less than effective. Hyperbaric oxygen therapy, during which oxygen was delivered to subjects at twice than normal atmospheric pressure, and bromelain, a substance found in abundance in pineapple and long-implicated as a treatment for certain inflammatory conditions, were both ineffective in relieving DOMS.

The omega-3 fatty acids in fish oil have been shown to reduce joint tenderness in arthritic patients. They have also demonstrated an ability to inhibit the release of pro-inflammatory cytokines during early stages of heart disease. In a third examination of DOMS, however, researchers recorded no difference among subjects who received fish oil supplements or a placebo, suggesting that the mechanism involved in DOMS may be different than that of poor blood supply to the heart.

In another study, 24 males were randomly assigned to receive either three doses of acetaminophen totaling 4000 mg, three doses of ibuprofen totaling 1200 mg, or placebo capsules indistinguishable from the other pills. DOMS was induced with eccentric (lengthening) contractions of the knee. The drug doses were administered at the onset of the injury protocol, and then at six-hour intervals, with a fourth dose the following morning. A muscle biopsy was taken five hours later to determine neutrophil and inflammatory cell concentrations (repair indicators).

Neutrophil concentrations were not significantly altered 24 hours after exercise, nor were inflammatory cell levels affected by either treatment. Furthermore, both acetaminophen and ibuprofen reduced protein synthesis, suggesting that these drugs may negatively regulate muscle growth after eccentric exercise. The researchers conclude that maximal over-the-counter does of ibuprofen or acetaminophen do not show signs of aiding the muscle repair process 24 hours after inducing soreness, and may even diminish muscle strength in the long run.

The jury is out on arnica, a topical homeopathic medicine that is also sometimes ingested. While the herb seems to elicit positive anecdotal feedback, one London study found it to be ineffective as an anti-inflammatory following long distance running. Over 500 marathoners were randomly assigned arnica or a placebo cream in a double-blind experiment monitoring their muscle soreness every morning and evening for five days postrace. There was no distinguishable difference among the 400 runners from whom results were obtained. In 1990, Oslo Marathon participants reported less stiffness with an oral regimen of five pills twice daily for five days, starting two days prior to the event. This study, though double-blind, calls for a larger sample size since there were only 36 runners total, half of which received a placebo.

Arnica, also known as leopard's bane, has traditionally found use as an anti-inflammatory in the treatment of bruises, sprains and rheumatism. It is believed that the substance helenalin found in the flower heads of the plant stimulates phagocytosis, the process by which cells clear out waste and repair tissue damage.

One promising treatment for DOMS is massage. Eighteen volunteers were randomly assigned to a massage or control group; DOMS was induced with six sets of eccentric contractions of the right hamstring. Two hours later, either 20 minutes of classical Swedish massage or a "sham massage" were administered. Peak torque and mood were assessed four times up to 48 hours post-exercise. Range of motion and intensity of soreness were assessed at 6, 24 and 48 hours. Neutrophil count (the repair indicator) was assessed at 6 and 24.

Of these factors, only intensity of soreness was significantly lower in the massage group, at 48 hours post-exercise. Thus, though hamstring function was not improved, massage remains a promising treatment for the pain associated with DOMS. The mechanism for the improvement in soreness now needs to be identified.

Lastly, in a double-blind placebo-controlled examination of 32 males, ages 18 to 35, a topical non-steroidal anti-inflammatory drug (NSAID) appeared effective. Subjects performed DOMS-inducing quadriceps exercises and then were immediately administered either transdermal ketoprofen or a placebo cream. Subjective measure of DOMS was assessed at baseline, 24 and 48 hours.

Subjects reported significantly lower DOMS on the leg administered ketoprofen than on the placebo leg. A 37% mean reduction in muscle soreness was recorded after 48 hours, when the difference was greatest. Between ketoprofen users and those receiving the placebo, the difference was greatest in the right leg after 48 hours, with a mean DOMS reduction of 45%. Notably, systemic absorption of the topical NSAID was minimal, and unlike some instances of oral NSAID use, no adverse reactions were recorded.

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