EFFECTS OF CONJUGATED LINOLEIC ACID AND RESISTANCE TRAINING IN RECREATIONAL ATHLETES

Abstract

Conjugated linoleic acid (CLA) is a mixture of positional and geometrical isomers of linoleic acid, that are known to posses several physiological effects such as enhancing immune response, reducing arteriosclerosis risk, and inhibiting carcinogenesis. Over the last decade, the use of CLA supplement has become widespread among elite and recreational athletes because it should increase training effects, improve fat oxidation, increase energy delivery, reduce body weight, improve lipid profile, and so on. The purpose of this project is to investigate whether CLA supplementation after a resistance training session affects general markers of muscle damage, total testosterone, cortisol and sex hormone binding globulin. In a double-blind and randomized manner 13 recreational athletes were randomly assigned to supplement their diet with 6 g per day of an sunflower oil placebo or 6 g per day of CLA for 21 days. After two weeks of wash-out, all subjects crossed over to the opposite group for an additional 21 days. The 3 weeks of supplementation were preceded and followed by a resistance training session involved 8 exercise, chosen to include all major muscle groups, consisting of 3 sets of 10 repetitions at approximately 75-80% of one-repetition maximum. Before and after the training session were drawn blood to measure the creatine phosphokinase, lactate dehydrogenase, creatine kinase mass, total testosterone, cortisol and sex hormone binding globulin concentrations. Measurements at baseline and after the 3 week of supplementation included body composition and stregth. The results indicate that CLA supplementation during resistance training should increase the anabolic effect and decrease the catabolic effects of training on muscle protein.