The effects of honest and dishonest placebo ingestion immediately prior to VO_2peak and handgrip strength testing

Abstract

Objectives: The purpose of this study was to examine the effects of both known (“honest”) and unknown (“dishonest”) placebo ingestion on VO_2peak to see if placebo ingestion would influence the test outcome by influencing the psychological compo nent of this test. A secondary purpose was to examine these effects on isometric handgrip strength. We hypothesized that placebo (honest or dishonest) ingestion prior to a VO_2peak test would increase VO_2peak compared to a control condition. We further hypothesized that isometric handgrip strength would be greater during both conditions of acute placebo ingestion compared to a control condition. Design: In a randomized, cross-over, counterbalanced design, subjects performed three trials: exercise tests with honest place bo, exercise tests with dishonest placebo, exercise tests only (control condition). Method: 41 subjects (28 males) aged 24 ± 7 years were tested. RM ANOVAs (3 × 1) were used to analyze VO_2peak and handgrip strength across conditions. RM ANOVAs (3 × 1) were used to determine if test order influenced VO_2peak and handgrip strength. (Alpha = 0.05.)Results: No differences were found across conditions for either VO2peak (p = 0.360) or handgrip strength (p = 0.474). Further, no differences were found for trial order for either VO2peak (p = 0.766) or handgrip strength (p = 0.067). Conclusions: Administration of both an honest and a dishonest placebo immediately prior to VO_2peak and handgrip testing resulted in no differences in performance compared to each other or a control trial. The VO_2peak test is a robust exercise test not influenced by immediately-prior pre-workout supplement consumption.