title: High resolution MEMS accelerometers to estimate VO2 and compare running mechanics between highly trained inter-collegiate and untrained runners.
abstract: BACKGROUND
  The purposes of this study were to determine the validity and reliability of high resolution accelerometers (HRA) relative to VO(2) and speed, and compare putative differences in HRA signal between trained (T) and untrained (UT) runners during treadmill locomotion.
  
  
  METHODS
  Runners performed 2 incremental VO(2max) trials while wearing HRA. RMS of high frequency signal from three axes (VT, ML, AP) and the Euclidean resultant (RES) were compared to VO(2) to determine validity and reliability. Additionally, axial rms relative to speed, and ratio of axial accelerations to RES were compared between T and UT to determine if differences in running mechanics could be identified between the two groups.
  
  
  RESULTS
  Regression of RES was strongly related to VO(2), but T was different than UT (r = 0.96 vs 0.92; p<.001) for walking and running. During walking, only the ratio of ML and AP to RES were different between groups. For running, nearly all acceleration parameters were lower for T than UT, the exception being ratio of VT to RES, which was higher in T than UT. All of these differences during running were despite higher VO(2), O(2) cost, and lower RER in T vs UT, which resulted in no significant difference in energy expenditure between groups.
  
  
  CONCLUSIONS
  These results indicate that HRA can accurately and reliably estimate VO(2) during treadmill locomotion, but differences exist between T and UT that should be considered when estimating energy expenditure. Differences in running mechanics between T and UT were identified, yet the importance of these differences remains to be determined.
authors.affiliation: Applied Physiology Laboratory, Eastern Michigan University, Ypsilanti, Michigan, United States of America. smcgregor@emich.edu
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: McGregor
authors.forename: Michael A
authors.initials: MA
authors.lastname: Busa
authors.forename: James A
authors.initials: JA
authors.lastname: Yaggie
authors.forename: Erik M
authors.initials: EM
authors.lastname: Bollt
mesh_terms: D000328:Adult; D056352:Athletes; D001696:Biomechanical Phenomena; D002151:Calorimetry / Q000379:methods; D004734:Energy Metabolism; D004867:Equipment Design; D005080:Exercise Test; D006801:Humans; D008297:Male; D015233:Models, Statistical; D009068:Movement; D010101:Oxygen Consumption; D010807:Physical Endurance; D010809:Physical Fitness; D012420:Running