A common misconception about Clenbuterol is that it has anabolic properties, and can increase muscle mass when used in higher dosages. This claim has never been substantiated, and likely originated from equine research. A beta-2 agonist, Clenbuterol has been found to increase short-term work rate and cardiovascular output, and consequently, its anabolic effects in horses can be attributed to exercise output and increased caloric intake. Given its ability to increase basal metabolic rate, maximum heart rate, and exercise output, Clenbuterol has ergogenic properties more closely related to ephedrine or amphetamine.