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

This study assessed the validity of power output recorded using an air-braked cycle ergometer (Kingcycle(TM)) when compared with a power measuring crankset (SRM(TM)). 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 x/divided by 1.07, and for PPO and 16.1 km TT ratio limits of agreement were 0.90 (95%CI = 0.88-0.92) x/divided by 1.07 and 0.92 (95%CI = 0.90-0.94) x/divided by 1.07, respectively. This data revealed that the Kingcycle ergometry system did not provide a valid measure of power output when compared with SRM.