The Effects of Non-Contingent Feedback on the Incidence of Plateau at VO2max

摘要

The purpose of this study was to examine the effects of non-contingent feedback in the form of heart rate (HR) on the inci-dence of plateau at 2max. Ten physically active males (age 24.8 yrs ± 4.2; mass 81.4 ± 9.0 kg; stature 1.80 ± 0.11 m, 2max 53.2 ± 5.8 ml.kg-1.min-1) who were OV2max testing naïve but were cognisant as to the heart rate responses to exercise com-pleted four incremental tests to volitional exhaustion, separated by ~72 h for the determination of 2max and gas exchange threshold. The first trial served as a familiarisation with the remaining three being experimental conditions where HR was presented in a screen projection as either the actual response (HR-A) or 10 b.min-1 higher than recorded (HR-H) or 10 b.min-1 lower (HR-L). Throughout all trials OV2 was recorded on a breath-by-breath basis with plateau criteria of ≤ 50 ml.min-1. RESULTS: A significant difference was observed for Δ2 over the final two consecutive 30s sampling periods between HR-A, both HR-L and HR-H (p = 0.049) and for the incidence of plateau response between condition (p = 0.021). An addition-al significant difference was observed for sub-maximal Δ2 responses between HR-A and HR-H (p = 0.049) and HR-A and HR-L (p = 0.006). Non-significant differences were observed for all other criteria. These data indicate that when presented with non-contingent feedback in the form of HR, that the per-ceptually orientated pacing schema becomes disrupted promot-ing a sparing of the finite anaerobic capacity to compensate for the imbalance between the afferent signal and perception of effort.G