Time Deception Affects Performance But Not Metabolic Variables In Cyclists

Abstract

PURPOSE: Previous investigations have found that various types of deception (ie. unknown task endpoint) could alterperception and consequently affect performance. We investigated whethertime deception influenced performance and metabolic variables in cyclists. METHODS: Ten semi-professional male cyclists (age 36±5, years; height 173±6 cm; weight 76.7±265 kg; with 2 years of experience) completed three 60 min cycling time trials (roller trainer)after 2 familiarization sessions. Visual feedback of elapsed time was provided, but the chronometer was manipulated to display either real (NOR), 10% slower(SLO) or 10% faster time lapse (RAP). Total distance covered and heart rate (HR) were recorded at each 10 min interval. Ratings of perceived exertion (RPE) were assessed with the 20-point Borg scale. Blood samples were collected before and immediately after each time trial, and analyzed for blood glucose, serum creatinine, serum urea, and serum urate. Data were analyzed with repeated measures ANOVA. Significant main effects were further analyzed using pairwise comparisons with Bonferroni post hoc tests. Statistical significance was set at the p≤ 0.05 level of confidence. Statistical analysis was completed using SPSS v20.0 for Windows (LEAD Technologies). RESULTS: Distance completed at any 10min time point was similar between conditions, but total distance covered over the 60 min differed among conditions (NOR = 20.7±4.1; SLO = 25.7±7.1; RAP = 23.7±5.2 Km) (p < 0.05). Post-hoc analyses indicated that both RAP (p = 0.001) and SLO (p = 0.027) covered a greater total distance than NOR, with no difference in distance covered between SLO and RAP (p=0.458).RPE (NOR = 17±3; SLO = 16±4; RAP = 18±1) and HR(NOR = 171±12; SLO = 172±17; RAP = 180±12bpm) were similar (p = 0.145) among conditions..Blood glucose increased during the time trial for all conditions, however increases in blood glucose (NOR = 7.4±10.7; SLO = 5.2±8.6; RAP = 6.8±13.3 mg.dl-1) were similar among all conditions. Serum creatinine, serum urea and serum urate were stable and did not differ among conditions. CONCLUSION: These results indicate that deception (±10%)consisting of either a slower or more rapid perception of elapsed time canincrease performance in a time trial, but does not affect RPE nor the measured metabolic variables in semi-professional cyclists.