| Popis: |
Despite the available literature addressing the placebo effect regarding performance, there is a paucity of research addressing the possibility of a placebo effect both within and between bouts of repeated sprint performance. Therefore, the purpose of this study was to determine if the administration of a placebo influences recovery during and between sessions of intermittent sprinting. Ten sprint-trained participants performed a series of repeated sprint tests under two different conditions in a counterbalanced order; one where they were administered a control beverage (i.e., water) and another with an experimental beverage (i.e., placebo). Each testing session consisted of three repeated anaerobic sprint tests (RAST) on a non-motorized treadmill with seven minutes of recovery between sets. Participants were then given 24-hours of recovery whereupon the repeated sprint test protocol was repeated. Ratings of perceived exertion were recorded within five seconds after each sprint. Following each RAST, participants were asked to rate their pain using a visual analog scale which was followed by a blood lactate sample drawn. Participants were then asked to rate their recovery using the perceived recovery status scale 30 seconds before beginning each subsequent RAST. Power was recorded throughout each session from a non-motorized treadmill in order to analyze changes in sprinting performance. Approximately 20 minutes following the final sprint, participants provided a session rating of perceived exertion to rate the global difficulty of the session. A 2x3 repeated measures ANOVA was used to determine significant differences in peak power, mean power, decrement score, recovery score, perceived recovery status, rating of perceived exertion, pain, and blood lactate between RASTs and conditions. Results from the analyses revealed no significant differences between conditions during the day one testing session. However, results showed the experimental condition produced significantly higher peak power (p < 0.001) and mean power (p = 0.002) versus the control condition in RAST3 of the day two session. These findings were observed in absence of any other significant difference in metabolic or perceptual strain (p > 0.05). In conclusion, it appears the administration of a placebo can attenuate the decline in performance as fatigue increases during repeated sprinting bouts. |
