Does Power Output at Critical Power Intensity Interchange between Cycling and Running?

The differences in power meters and gestures between cycling and running can have an impact on determining Critical Power (CP) intensity in each sport. CP is a concept that has been extensively researched in cycling, but with the advent of power measurement in running, it can now be examined in that discipline as well. The purpose of the present study was to determine whether power output at CP intensity is interchangeable between cycling and running segments measured with their respective discipline-specific power meters. A group of 18 trained triathletes (age 33.0 ± 11.1 years, height 1.75 ± 0.06 m, body mass 71.2 ± 7.1 kg) performed a CP test in cycling (3-min All-Out Test) and running (9/3-min Stryd CP Test). The main results of the present study showed significant differences (p < 0.001) between CP in cycling and running. The running CP (301.8 W ± 41.5 W) was 20.2% overestimated compared with the cycling CP (251.1 W ± 37.0 W). Cycling power only explained 26.7% of the running power (R2 = 0.267; p = 0.284). Therefore, power would not be interchangeable between the cycling and running disciplines at CP intensity. In conclusion, it would be necessary to carry out a specific test for each discipline to be able to make a correct determination of CP.