Influence of test duration on oxygen uptake attained during treadmill running

Abstract

Previous investigations have revealed that in well-trained middle-distance runners, oxygen uptake (VO₂) does not attain maximal values (VO_2max) in exhaustive treadmill trials where the VO₂ demand exceeds VO_2max. To date, this shortfall in the VO₂ attained has been demonstrated in trials as short as 2 min in duration. In this study, we investigated whether a reduction in exhaustive test duration influences the VO₂ attained during running on a treadmill. Six middle-distance runners participated in the study, completing an exhaustive 400 m and 800 m trial. These trials, together with a progressive test to determine VO_2max, were completed in a counterbalanced order. Oxygen uptakes attained during the 400 m and 800 m trials were compared to examine the influence of exhaustive test duration. A plateau in VO₂ was observed in all participants for the progressive test, demonstrating the attainment of VO_2max. The mean speed, duration, and resulting distance in the constant-speed exhaustive trials were 25.8 km · h⁻¹ (s=1.2), 55.8 s (s=2.3), and 400.2 m (s=20.2) for the 400 m trial, and 24.3 km · h⁻¹ (s=0.8), 108.4 s (s=21.2), and 730.1 m (s=129.1) for the 800 m trial, respectively. A paired-samples t-test revealed a significantly different (P=0.018)%VO_2max was attained for the 400 m (85.7%, s=3.0) and 800 m (89.1%, s=5.0) trials. In conclusion, VO₂ did not reach VO_2max during the exhaustive constant-speed 400 m and 800 m trials, but the test duration does influence the%VO_2max achieved. Specifically, the VO₂ attained becomes progressively further below VO_2max as trial duration is reduced, such that 89% and 86% VO_2max is achieved in exhaustive 800 m and 400 m constant-speed trials, respectively.

Keywords:

• VO2 response
• middle-distance
• 400 m
• 800 m

Acknowledgements

During the investigation Leigh E. Sandals was in receipt of a University of Gloucestershire Research Studentship. The University of the Basque Country has supported and financed (NUPV06/14) the participation of Sara Maldonado-Martín.