What is the connection between a cold and big muscles? Compared with a placebo drug, the daily-recommended dosages of ibuprofen and acetaminophen (paracetamol) have been found to induce a significant higher growth of quadriceps muscle mass and strength gained in three months of regular weight lifting, as revealed by a team from the Human Performance Laboratory, Ball State University, and presented at Experimental Biology 2008 in San Diego, on April 6.

36 subjects of both genders, aged from 60 to 78 (average age 65), were randomly demanded to take daily amounts of ibuprofen (like in Advil), acetaminophen or paracetamol (like in Tylenol), or a placebo.

The doses were those recommended by the producers and were chosen to resemble what chronic users would probably take. The volunteers followed a three months program of weight training on three weekly sessions of 15-20 minute each.

The placebo group was expected to display a growth in muscle mass, but the surprise was that both ibuprofen and acetaminophen did grow and even more!

The same team had assessed muscle anabolism (muscle protein synthesis) over a 24-hour period at the "acute" exposure to both ibuprofen and acetaminophen, and the results had been negative, showing that the drugs blocked the cyclooxygenase enzyme (COX).

"Over three months, the chronic consumption of ibuprofen or acetaminophen during resistance training appears to have induced intramuscular changes that enhance the metabolic response to resistance exercise, allowing the body to add substantially more new protein to muscle," said co-author Dr. Todd Trappe,

The muscle growth was assessed in quadriceps muscles of the thighs using Magnetic Resonance Imaging (MRI). More detailed muscle biopsies taken before and after the three-month period of resistance training could explain the positive changes of the muscle metabolism induced by ibuprofen and acetaminophen.

The results could have many applications, from easing the adaptation of the elders to exercise to hampering the loss of muscle mass of the astronauts during long-term space journeys, when they are exposed to weightlessness. Do not forget the bodybuilders and other sportsmen.