The validity of power output recorded during exercise performance tests using a Kingcycle air-braked cycle ergometer when compared with an SRM powermeter

J. Balmer, R.C.R. Davison, D.A. Coleman, S.R. Bird

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This study assessed the validity of power output recorded using an air-braked cycle ergometer (Kingcycle™) when compared with a power measuring crankset (SRM™). For part one of the study thirteen physically active subjects completed a continuous incremental exercise test (OBLA), for part two of the study twelve trained cyclists completed two tests; a maximal aerobic power test (MAP) and a 16.1 km time-trial (16.1 km TT). The following were compared; the peak power output (PPO) recorded for 1 min during MAP, the average power output for the duration of the time-trial and power output recorded during each stage of OBLA. For all tests, power output recorded using Kingcycle was significantly higher than SRM (P < 0.001). Ratio limits of agreement between SRM and Kingcycle for OBLA showed a bias (P < 0.00) of 0.90 (95 %CI = 0.90 - 0.91) with a random error of ×/÷ 1.07, and for PPO and 16.1 km TT ratio limits of agreement were 0.90 (95 %CI = 0.88 - 0.92) ×/÷ 1.07 and 0.92 (95 %CI = 0.90 - 0.94) ×/÷ 1.07, respectively. This data revealed that the Kingcycle ergometry system did not provide a valid measure of power output when compared with SRM.
Original languageEnglish
Pages (from-to)195-199
Number of pages5
JournalInternational Journal of Sports Medicine
Issue number3
Publication statusPublished - Apr 2000
Externally publishedYes


  • validity
  • measurement error
  • cycling
  • time trial
  • peak power output

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