The Effects of Non-Contingent Feedback on the Incidence of Plateau at V̇O2max.
The purpose of this study was to examine the effects of non-contingent feedback in the form of heart rate (HR) on the incidence of plateau at V̇O2max. Ten physically active males (age 24.8 yrs ± 4.2; mass 81.4 ± 9.0 kg; stature 1.80 ± 0.11 m, V̇O2max53.2 ± 5.8 ml·kg-1.min-1) who were V̇O2maxtesting naïve but were cognisant as to the heart rate responses to exercise completed four incremental tests to volitional exhaustion, separated by ~72 h for the determination of V̇O2maxand 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-1higher than recorded (HR-H) or 10 b·min-1lower (HR-L). Throughout all trials V̇O2was recorded on a breath-by-breath basis with plateau criteria of ≤ 50 ml·min-1.


RESULTS
A significant difference was observed for Δ V̇O2over 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 additional significant difference was observed for sub-maximal Δ V̇O2responses 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 perceptually orientated pacing schema becomes disrupted promoting a sparing of the finite anaerobic capacity to compensate for the imbalance between the afferent signal and perception of effort.
Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University , UK.
Dan
D
Gordon
Faculty of Sport, University of Montpellier , France.
Marie
M
Gernigon
Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University , UK.
James
J
Baker
Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University , UK.
Viviane
V
Merzbach
Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University , UK.
Adrian
A
Scruton
Pacing; V̇O2-plateau; V̇O2max; incremental exercise