Placebo Effect on Muscle Strength Performance in Experienced Men in

Abstract

Introduction: The placebo effect originates in the late eighteenth century, when it gained medical mastery by using substances considered ineffective based on the therapeutic effect difficult to explain, and its results have been greatly confused with the use of food supplements. Objective: The purpose of the present study was to evaluate the placebo effect when compared to caffeine supplementation and control groups during a strength training session. Materials and Methods: Fifteen experienced in strength training male subjects were submitted to a protocol of 3 sets of 10RM for bench press (BP) and leg extension (LE), randomly following three conditions: with no supplementation (C), supplementation with 250 mg of caffeine (S) or placebo (P). All subjects were submitted to an anthropometric evaluation, followed by a 10RM familiarization test. After a 48h period, each volunteer accomplished randomly three other 10RM tests according to C, S or P. Results: No significant differences were found for the load 10RM in BP and LE exercises, compared to different interventions. The placebo effect resulted in load 10RM higher in the BP and LP exercises when compared to the control intervention with an increase of 8% and 6.8%, respectively. Conclusion: The results of the present study suggest that a placebo effect on submaximal muscle strength is present over a session of strength training.