Int J Sports Med 2004; 25(6): 415-420
DOI: 10.1055/s-2004-820960
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Oxygen Uptake-Work Rate Relationship During Two Consecutive Ramp Exercise Tests

A. M. Jones1 , H. Carter2
  • 1Department of Exercise and Sport Science, Manchester Metropolitan University, Alsager, United Kingdom
  • 2Chelsea School, University Of Brighton, Eastbourne, United Kingdom
Further Information

Publication History

Accepted after revision: March 16, 2004

Publication Date:
27 May 2004 (online)

Abstract

The performance of prior high intensity constant work rate (CWR) exercise significantly influences the gain of the fundamental oxygen uptake (V·O2) response during subsequent high intensity CWR exercise. The purpose of the present study was to investigate whether equivalent effects could be elicited in the second of two bouts of exhaustive ramp exercise. We therefore hypothesised that a prior bout of exhaustive ramp exercise would increase the V·O2-work rate (ΔV·O2/ΔWR) slope during subsequent ramp exercise. Nine healthy males performed two ramp exercise tests to exhaustion on an electrically braked cycle ergometer separated by a 10-min period of cycling at 20 W. Pulmonary V·O2 was measured breath-by-breath throughout both tests, and the mean response time (MRT) and the ΔV·O2/ΔWR slope for exercise below the gas exchange threshold (GET) (S1), above the GET (S2), and over the S1 + S2 region (ST) were determined. Paired t-tests were used to analyse the data with significance accepted at p < 0.05. Blood [lactate] was higher at the onset of the second ramp test compared to the first (mean ± SEM 1.2 ± 0.1 vs. 6.2 ± 0.7 mM; p < 0.01), but baseline V·O2 was not significantly different between tests (0.93 ± 0.05 vs. 0.99 ± 0.06 L · min-1). The MRT (42 ± 4 vs. 40 ± 5 s) did not differ between tests, but the ΔV·O2/ΔWR slope was steeper in the second ramp test for S2 (9.1 ± 0.4 vs. 9.8 ± 0.5 ml · min-1 · W-1; p < 0.01) and ST (9.0 ± 0.4 vs. 9.6 ± 0.5 ml · min-1 · W-1; p < 0.05). The demonstration that prior ramp exercise increases the ΔV·O2/ΔWR slope during subsequent ramp exercise is consistent with the results of previous CWR studies and indicates that exercise economy is sensitive to the prior activity of the engaged muscles.

References

Dr A. M. Jones

Department of Exercise and Sport Science, Manchester Metropolitan University

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Alsager, ST7 2 HL

United Kingdom

Phone: + 01612475656

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Email: [email protected]