Jessica Moon1, Christian Espitia2, Landon Hiebert2, Christopher A. Fahs2, Lindy M. Rossow2

1Lindenwood University, St. Charles, Missouri; 2Lindenwood University-Belleville, Belleville Illinois

Pre-exercise consumption of placebo has been shown to improve resistance and endurance exercise performance. However, the effects of placebo ingestion on graded exercise test performance have not been widely reported in the literature. PURPOSE: The purpose of this study was to examine the effects of honest (subjects were told they were consuming placebo) or dishonest (subjects were told they were consuming a pre-workout supplement) placebo ingestion on VO2peak values determined during a maximal treadmill graded exercise test. A secondary purpose of this study was to examine the effects of placebo consumption on isometric handgrip performance. We hypothesized that pre-exercise ingestion of both placebo conditions would result in increased VO2peak and handgrip performance compared to control. METHODS: 28 males (178.4 ± 6.94 cm, 83.3 ± 14.8 kg, 22.6 ± 2.3 yrs.) and 13 females (166.4 ± 8.49 cm, 73.6 ± 20 kg, 26.4 ± 11 yrs.) participated in this study. In a randomized, cross-over design, subjects performed treadmill VO2peak and isometric handgrip testing after consumption of honest placebo (HP) or dishonest placebo (DP). In addition, a third baseline trial (CON) was performed to establish performance values that were unaffected by a perceived placebo effect due to supplementation. All outcomes were assessed for normality using the Shapiro-Wilks test. When assumptions of normality were violated, log transformations were computed. However, transformations did not improve model assumptions. Therefore, non-transformed data is reported. One-way ANOVAs were used to analyze VO2peak and handgrip strength data across conditions. Alpha was set at 0.05 prior to all analyses. RESULTS: Significant between-groups differences (p < 0.05) were not detected for relative VO2peak (CON = 46.2 ± 9.3 mL/kg/min; HP = 46.7 ± 10 mL/kg/min; DP = 46.6 ± 9.6 mL/kg/min) or for maximal handgrip strength (CON = 43 ± 9.6 kg; HP = 44.1 ± 12.4 kg; DP = 43.4 ± 12.1 kg). CONCLUSION: Administration of honest or dishonest placebo immediately prior to VO2peak and handgrip testing had no effect on performance compared to control. The VO2peak and isometric handgrip tests were found to be robust exercise tests not significantly influenced by perceived pre-workout supplement consumption

Moon Table 1.docx (15 kB)
Moon Table 1

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