We all realize that most of our food comes from farms, hut frequently the agricultural industry produces more than just the food we put on our dinner plate. Such is the case with a class of drugs known as beta 2-adrenergic agonists, or beta-agonists for short. When researchers
found that these drugs had potent effects on the contractile and growth responses of skeletal muscle in livestock, some scientists asked the next logical question: "What about in humans?".
A study hot off the presses published in the journal of Strength and conditioning Research examined the effects of exercise and beta-agonist administration, specifically albuterol, on muscle over a specific period. Those of you with asthma are probably familiar with this drug albuterol helps relax the smooth bronchial muscles in the lungs via its action on the beta-agonist receptors. Who would've thought that an asthmatic drug could induce changes in muscle size and strength?
Scientists at the University of Miami in Coral Gables, Florida, examined 22 non asthmatic sedentan-individuals and recreational athletes. Albuterol or a placebo was administered four times a day for a total of lb mg per day. These treatments were randomized and double- blinded (meaning even the researchers didn't know during the study which group was receiving the real drug). The subjects' training consisted of knee extensions (concentric- eccentric contractions) on a Biodex Systems dynamometer, and they performed three sets of 10 repetitions with their right leg at 45 degrees pet second - a pretty slow contraction. Rest intervals were two minutes between sets. Training lasted nine weeks, while the albuterol or placebo administration commenced on week three and terminated at nine weeks.
Using various measures of strength and power, the investigators found significant differences in strength gains between the placebo and albuterol groups. In general, after one month of training, the albuterol-supplemented group displayed higher values for eccentric and concentric peak torque relative to bodyweight. Thus, the albuterol group experienced true gains in strength that weren't associated with lust a bodyweight gain.
Furthermore, the differences were greater between the two groups with regard to eccentric strength. Eccentric contractions are known to produce microtears in muscle fibers, resulting in the phenomenon known as delayed-onset muscle soreness. By some unknown mechanism, albuterol may in fact hasten recovers from eccentric bouts of exercise. Whether this translates into more growth or strength in the long run isn't clear.
Beta-agonists can he used to treat atrophic conditions. For instance, the beta-agonist metaproterenol may induce gains in muscle strength and size in paralyzed patients after spinal-cord injury. Whether beta- agonist administration is the best choice of drug therapy to combat wasting is unclear, since you could make a convincing argument that better anabolic compounds exist, Nevertheless, beta-agonists have been shown to elicit significant effects in both healthy humans and those with atrophic conditions.