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That morning cup of coffee may stop your muscles hurting after exercise, new research shows
In a small study of female college students, researchers found that a caffeine supplement seemed to lessen the muscle pain that crops up the day after a particularly challenging workout.
Known as delayed-onset
muscle soreness, or Doms, the pain is common in the day or two after an intense workout.
Exercise that involves eccentric contraction of the muscles, which happens while the muscle is lengthened, is particularly likely to cause delayed muscle pain. This happens when a person runs downhill, for example, or lowers a weight during a bicep curl.
Exercisers and researchers alike have tried many ways to prevent Doms - including over-the-counter painkillers, stretching and massage - but studies have found no cure-all.
In the current study, published in the Journal of Pain, researchers at the University of Georgia looked at the effects of a caffeine supplement on delayed muscle pain in nine young women.
First, the researchers used electrical stimulation to produce eccentric contractions in the women's thigh muscles - enough to cause moderate soreness the next day.
They repeated the procedure over the next two days, but each time, the women took either a caffeine pill or placebo pill one hour before the muscle workout. Neither the women nor the researchers knew which pill was given on which day.
The women reported significantly less muscle soreness when they took caffeine, equal to the amount found in two cups of coffee, instead of the placebo.
The theory is that caffeine eases delayed muscle pain by blocking the activity of a chemical called adenosine, which is released during the inflammatory response to injury. Adenosine can activate pain receptors in body cells, explained Victor Maridakis, the study's lead author.
He said the pain relief from caffeine was stronger than that from painkillers such as acetaminophen (Tylenol) and naproxen (Aleve).
Mr Maridakis noted that research into another popular pain reliever, ibuprofen, has shown inconsistent results, and it's unclear whether the drug helps ease sore muscles.
Before downing a couple of cups before your workout, however, Maridakis recommends you consider carefully caffeine's possible side-effects.
"The negative side-effects of caffeine are increased feelings of anxiety, heart palpitations, increased blood pressure, upset stomach, increased urination and disrupted sleep," he explained.
"Caution should be used when consuming caffeine so not to exacerbate these side-effects."
Though most people are "normal responders" to caffeine, Mr Maridakis noted, some are hypersensitive to it and are at higher risk of side-effects.
However, people who drink a couple of cups of coffee a day tend to become desensitised to caffeine, the study authors point out, and it's unclear whether a dose of caffeine would aid their post-workout muscle pain.
- REUTERS