Author(s): PARRY, H., BAILEY, S., BURNLEY, M., Institution: LOUGHBOROUGH UNIVERSITY, Country: UNITED KINGDOM, Abstract-ID: 2527

INTRODUCTION:
The severe domain is characterised by power outputs where V̇O2max is achieved. Higher exercise demands result in task failure occurring before V̇O2max can be attained in the extreme domain as a result of the V̇O2 kinetic response being inadequate (in both speed and amplitude). The boundary between these domains is therefore defined as the highest power output where V̇O2max is achieved. Priming exercise has consistently increased the speed of the overall V̇O2 kinetic response in the transition to the severe domain, primarily as a consequence of an increased primary V̇O2 amplitude (e.g., [1]). Consequently, these experiments were designed to test the hypothesis that priming exercise would increase the range of power outputs within which V̇O2max can be attained, and thus increase the severe-extreme domain boundary.
METHODS:
Nine participants completed a ramp incremental and verification cycling test. Constant load cycling bouts were performed at 90% delta (the difference between the gas exchange threshold and peak ramp test power), 105, 120, and 135% of peak ramp test power following baseline pedalling and a 5-min constant load priming bout at 70% delta and 20-min of rest and baseline pedalling. The time to the limit of tolerance and V̇O2peak were identified in each bout. The greatest primed and non-primed severe bout power output where V̇O2max was achieved was identified with multiple V̇O2max criteria , e.g., if greater than 95% of the ramp test V̇O2peak. Across primed and non-primed severe bouts, mono-exponential V̇O2 kinetic models were used to determine the primary V̇O2 response. The time to V̇O2max (TV̇O2max) was calculated as the modelled time constant · 4, and for interpolated V̇O2 to surpass the mean – 1SD of V̇O2max.
RESULTS:
Across all bouts, V̇O2peak was increased in primed (3700 ± 111 ml/min) compared to non-primed bouts (3492 ± 132 ml/min, p < 0.001). The highest severe power output was increased following priming (407 ± 71 W) compared to without priming (322 ± 39 W, p < 0.01). Indeed, seven participants achieved V̇O2max at a higher power output following priming compared to without priming. In severe primed and non-primed 90% delta bouts, the mean response time of the V̇O2 kinetic response was reduced following priming (58 ± 14 s vs 47 ± 5 s, p < 0.05). In the same bouts, TV̇O2max was not significantly reduced following priming compared to without priming, calculated with modelled (201 ± 69 s vs 166 ± 28 s) and interpolated V̇O2 (167 ± 19 s vs 134 ± 24s).
CONCLUSION:
This study identified an improvement in the severe-extreme intensity domain boundary following a severe intensity priming bout. This improvement can be attributed to the shorter response time of the V̇O2 kinetic response in the transition to severe intensity exercise and therefore potentially TV̇O2max.

[1] Burnley, M., Davison, G., & Baker, J. R. Med. Sci. Sports Exerc 2011. 43(11), 2171–2179.