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10.3389_fphys.2020.613151.pdf (390.86 kB)

Relationship Between the Critical Power Test and a 20-min Functional Threshold Power Test in Cycling

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submitted on 2024-05-23, 06:21 and posted on 2024-05-23, 06:22 authored by Bettina Karsten, Luca Petrigna, Andreas Klose, Antonino Bianco, Nathan Townsend, Christoph Triska

To investigate the agreement between critical power (CP) and functional threshold power (FTP), 17 trained cyclists and triathletes (mean ± SD: age 31 ± 9 years, body mass 80 ± 10 kg, maximal aerobic power 350 ± 56 W, peak oxygen consumption 51 ± 10 mL⋅min–1⋅kg–1) performed a maximal incremental ramp test, a single-visit CP test and a 20-min time trial (TT) test in randomized order on three different days. CP was determined using a time-trial (TT) protocol of three durations (12, 7, and 3 min) interspersed by 30 min passive rest. FTP was calculated as 95% of 20-min mean power achieved during the TT. Differences between means were examined using magnitude-based inferences and a paired-samples t-test. Effect sizes are reported as Cohen’s d. Agreement between CP and FTP was assessed using the 95% limits of agreement (LoA) method and Pearson correlation coefficient. There was a 91.7% probability that CP (256 ± 50 W) was higher than FTP (249 ± 44 W). Indeed, CP was significantly higher compared to FTP (P = 0.041) which was associated with a trivial effect size (d = 0.04). The mean bias between CP and FTP was 7 ± 13 W and LoA were −19 to 33 W. Even though strong correlations exist between CP and FTP (r = 0.969; P < 0.001), the chance of meaningful differences in terms of performance (1% smallest worthwhile change), were greater than 90%. With relatively large ranges for LoA between variables, these values generally should not be used interchangeably. Caution should consequently be exercised when choosing between FTP and CP for the purposes of performance analysis.

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Published in: Frontiers in Physiology
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Open Access funding provided by the Qatar National Library.



  • English



Publication Year

  • 2021

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This Item is licensed under the Creative Commons Attribution 4.0 International License.

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  • Hamad Bin Khalifa University
  • College of Health and Life Sciences - HBKU

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