Int J Sports Med 2009; 30(1): 22-26
DOI: 10.1055/s-2008-1038744
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Reliability of the VmaxST Portable Metabolic Measurement System

J. Blessinger1 , B. Sawyer2 , C. Davis3 , B. A. Irving4 , A. Weltman5 , G. Gaesser5
  • 1Student Health Connection, California State University Sacramento, Sacramento, California, United States
  • 2Kinesiology, Point Loma Nazarene University, San Diego, California, United States
  • 3Cardiology, Rady Children's Hospital, San Diego, California, United States
  • 4Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, Minnesota, United States
  • 5Human Services, University of Virginia, Charlottesville, Virginia, United States
Further Information

Publication History

accepted after revision May 23, 2008

Publication Date:
23 July 2008 (online)

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Abstract

The purpose of this study was to evaluate the reliability of the VmaxST portable metabolic measurement system. Forty-five healthy adults (age = 25.7 ± 5.9 yr; height = 171.8 ± 9.1 cm; weight = 69.6 ± 12.8 kg; V˙O2peak = 40.7 ml/kg/min; percent fat = 21.7 ± 11.0) performed two separate and identical exercise routines on different days consisting of treadmill walking at 2.0 mph (53.6 m/min), 3.0 mph (80.5 m/min), and 4.0 mph (107.3 m/min) and running at 6.0 mph (160.9 m/min). V˙E and gas exchange were measured continuously breath-to-breath. A random effects model on log-transformed data yielded coefficients of variation (CV) and intraclass correlation coefficients (ICC) for V˙O2 and V˙E of 5.2 – 7.6 %, and 0.77 – 0.92, respectively, for all walking and running trials. For V˙CO2, CVs were higher (10 – 12 %) and ICCs lower (0.70 – 0.81). Ordinary least squares regression between the individual difference scores and the individual mean scores for V˙E, V˙O2 and V˙CO2, respectively, indicated no systematic bias (all p > 0.05). Bland-Altman analysis also illustrated no systematic bias between repeated measurements. The VmaxST provides reliable measurements of V˙O2 and V˙E during walking and running eliciting V˙E and V˙O2 at least up to ∼ 56 and 2.2 l/min, respectively. The system appears to be less reliable for measuring V˙CO2.

References

Prof. Glenn Gaesser

University of Virginia
Human Services

210 Emmet St., So., Box 400 407

22904 Charlottesville, Virginia

United States

Phone: + 1 43 49 24 35 43

Fax: + 1 43 49 24 13 89

Email: gag2q@virginia.edu