title: The accuracy of the ACSM stair-stepping equation.
abstract: OBJECTIVE
  The purpose of this study was to determine the accuracy of the ACSM equation used to estimate the oxygen cost of stepping exercise. The equation appears as: VO2 (mL.kg(-1).min(-1)) = 0.2 (steps.min(-1)) + (step height, m x steps.min(-1) x 2.4) + 3.5.
  
  
  METHODS
  Subjects were 55 men and women between the ages of 19 and 35 yr. Steady-state VO2 was measured at six different combinations of step heights and step rates. Step heights were 0.1, 0.2, and 0.3 m (4, 8, and 12 in, respectively) and step rates were 20 and 25 steps.min(-1). Predicted VO2 for each workload was derived from the ACSM equation.
  
  
  RESULTS
  Mean differences between actual and predicted VO2 values ranged from -0.2 to -1.1 mL.kg(-1).min(-1) and was -0.6 mL.kg(-1).min(-1) for all workloads combined. All differences except the lowest were significant (P < or = 0.05). Total errors ranged from 1.3 to 2.5 mL.kg(-1).min(-1) and was 1.9 mL.kg(-1).min(-1) for all workloads combined. For all workloads combined, the correlation between actual and predicted VO2 was r = 0.95 with a SEE = 1.7 mL.kg(-1).min(-1). The statistics are comparable to other ACSM prediction equations.
  
  
  CONCLUSIONS
  Although all of the mean differences except one were statistically significant, they were judged negligible from a practical standpoint. Therefore, it was concluded that the ACSM equation is an accurate predictor of the oxygen cost of stair-stepping exercise.
authors.affiliation: Exercise Physiology Laboratory, School of HPER, University of Nebraska at Omaha, 68182, USA. rlatin@mail.unomaha.edu
authors.forename: R W
authors.initials: RW
authors.lastname: Latin
authors.forename: K
authors.initials: K
authors.lastname: Berg
authors.forename: K
authors.initials: K
authors.lastname: Kissinger
authors.forename: A
authors.initials: A
authors.lastname: Sinnett
authors.forename: L
authors.initials: L
authors.lastname: Parks
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003627:Data Interpretation, Statistical; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*