Tabrett, Mark (2013) The Influence of Protocol on the Assessment of Economy of Movement. Masters thesis, University of Gloucestershire.
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It is suggested that only data below gas exchange threshold (GET) should be used in regressions to calculate economy of movement. The purpose of this study was to compare the accuracy of the prediction from sub-GET only data (incrementalsub) and the sub & supra GET data (incrementalfull) with a fixed work rate (WR) at an intensity typical of endurance performance. Twelve physically active male participants volunteered of age 29 ± 9 years, height 1.81 ± 0.07 m and body mass 81.4 ± 10 kg. The participants completed four separate tests each on a separate day. Initially performing a maximal ramp test (20 W.min-1) to volitional exhaustion at approximately 12 min. The other three tests included an incrementalsub and incrementalfull and a fixed WR and were counterbalanced for potential order and carryover effects. All tests were carried out on an electronically braked cycle ergometer and the cadence maintained at approximately of 80 rev.min-1. The data from the maximal test was used to determine peak power, the highest V̇O² over a 15 s sequential period (V̇O²peak) and GET. The incrementalsub method consisted of five stages six min in duration with equal transitions from 50 W to 95% GET. The incrementalfull method consisted of five stages six min in duration with equal transitions from 50 W to 85% Δ. The data collection period was set at 4-6 min for these tests. The criterion fixed WR consisted of ten min duration at a WR of 75% Δ and had two data collection periods set at 4-6 and 8-10 min. The data collection period of 8-10 min was used in all further analysis; as at the 4-6 min data collection period steady state had not been attained. A linear regression was conducted on the mean oxygen uptake (V̇O²) kinetic response at each data collection stage of the five WRs in the two predictive tests and the calculation of V̇O² requirement at 75% Δ performed. These two calculated and the measured V̇O² values of economy of movement at 75% Δ were then entered into repeated measures ANOVA to identify differences in the oxygen uptake (L.min-1). The ANOVA showed a significant effect of the method on V̇O² at 75% ∆ (p < 0.001). Post hoc analysis showed that both the incrementalsub and the incrementalfull underestimated the V̇O² requirement in the fixed WR (2.90 ± 0.40 L.min-1 (p<0.001) and 3.21 ± 0.47 L.min-1 (p=0.012) vs. 3.43 ± 0.45 L.min-1). Furthermore, the incrementalsub was significantly lower than the V̇O² estimated from the incrementalfull (p=0.037). Economy of movement should not be estimated using sub-GET data points only as this significantly underestimated the measured V̇O² requirement. The use of regressions from incremental tests that use a full range of WR data will reduce this error but still underestimate the measured V̇O² requirement. The impact of incremental designs on V̇O² kinetics requires further investigation to fully understand this effect.
|Item Type:||Thesis (Masters)|
|Additional Information:||Master of Science by Research|
|Uncontrolled Keywords:||Protocol, economy, slow component, linear regression, gas exchange threshold|
|Subjects:||G Geography. Anthropology. Recreation > GV Recreation Leisure|
|Divisions:||Schools and Research Institutes > School of Sport & Exercise > Sport and Exercise|
|Depositing User:||Susan Turner|
|Date Deposited:||03 Mar 2015 10:08|
|Last Modified:||14 Feb 2017 11:59|