title: Validity and reliability of the look Keo power pedal system for measuring power output during incremental and repeated sprint cycling.
abstract: Power meters have traditionally been integrated into the crank set, but several manufacturers have designed new systems located elsewhere on the bike, such as inside the pedals.
  
  
  OBJECTIVE
  This study aimed to determine the validity and reliability of the Keo power pedals during several laboratory cycling tasks.
  
  
  METHODS
  Ten active male participants (mean ± SD age 34.0 ± 10.6 y, height 1.77 ± 0.04 m, body mass 76.5 ± 10.7 kg) familiar with laboratory cycling protocols completed this study. Each participant was required to complete 2 laboratory cycling trials on an SRM ergometer (SRM, Germany) that was also fitted with the Keo power pedals (Look, France). The trials consisted of an incremental test to exhaustion followed by 10 min rest and then three 10-s sprint tests separated by 3 min of cycling at 100 W.
  
  
  RESULTS
  Over power ranges of 75 to 1147 W, the Keo power-pedal system produced typical error values of 0.40, 0.21, and 0.21 for the incremental, sprint, and combined trials, respectively, compared with the SRM. Mean differences of 21.0 and 18.6 W were observed between trials 1 and 2 with the Keo system in the incremental and combined protocols, respectively. In contrast, the SRM produced differences of 1.3 and 0.6 W for the same protocols.
  
  
  CONCLUSIONS
  The power data from the Keo power pedals should be treated with some caution given the presence of mean differences between them and the SRM. Furthermore, this is exacerbated by poorer reliability than that of the SRM power meter.
authors.affiliation: Dept of Sport and Physical Activity, Edge Hill University, Ormskirk, Lancashire, UK.
authors.forename: S Andy
authors.initials: SA
authors.lastname: Sparks
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dove
authors.forename: Craig A
authors.initials: CA
authors.lastname: Bridge
authors.forename: Adrian W
authors.initials: AW
authors.lastname: Midgely
authors.forename: Lars R
authors.initials: LR
authors.lastname: McNaughton
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D003362:Cost-Benefit Analysis; D004867:Equipment Design / Q000191:economics; D005080:Exercise Test / Q000191:economics / Q000295:instrumentation*; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D015203:Reproducibility of Results; D055815:Young Adult