Garmin Fénix 7® underestimates performance at the lactate threshold in comparison to standardized blood lactate field test

  • Jennifer Schlie Institute of Sport Sciences, Chair of Sport Biology, University of the Bundeswehr Munich, Germany https://orcid.org/0000-0001-8973-6353
  • Marie Heiber dtec.bw, NextGenerationEU Project Smart Health Lab, Chair of Sport Biology, University of the Bundeswehr Munich, Germany
  • Andrea Schittenhelm Institute of Sport Sciences, Chair of Sport Biology, University of the Bundeswehr Munich, Germany
  • Marcus Beckert Institute of Sport Sciences, Chair of Sport Biology, University of the Bundeswehr Munich, Germany
  • Pascal Graf Institute of Sport Sciences, Chair of Sport Biology, University of the Bundeswehr Munich, Germany
  • Annette Schmidt dtec.bw, NextGenerationEU Project Smart Health Lab, Chair of Sport Biology, University of the Bundeswehr Munich, Germany; Institute of Sport Sciences, Chair of Sport Biology, University of the Bundeswehr Munich, Germany & Research Center Smart Digital Health, University of the Bundeswehr Munich, Germany
DOI: https://doi.org/10.36950/2024.4ciss056
Keywords: smartwatch, physical performance, physiology, heart rate

Abstract

Introduction & Purpose

Lactate threshold (LT) is a critical performance measure traditionally obtained using costly laboratory-based tests. Wearables offer a practical and noninvasive alternative for LT assessment in recreational and professional athletes. However, the comparability of these estimates with the gold standards requires further evaluation. This study therefore aimed to compare pace and heart rate (HR) at the LT between the Garmin Fenix 7® threshold running test and a standardized blood lactate field test.

Methods

In our sample of 26 participants (nf = 7 and nm = 19; 25.97 (± 6.26) years, BMI: 24.58 (± 2.8) kg/m2) we determined running pace and HR at LT with two subsequent tests. First, all participants were equipped with a Fenix 7® smartwatch for a calibration phase of 5 weeks. Subsequently, all performed the Fenix 7® threshold running test, which guides the athlete through incrementing HR zones. Based on that, the watch estimated pace and HR at LT. After a break of at least 48 h, they were tested in a standardized, graded blood lactate field test analyzed by the modified D-Max method (Cheng et al, 1992).

Results

Pace at LT calculated by Fenix 7® (M =11.87 km/h ± 1.26 km/h) was 11,8% lower compared to the field test (M =13.28 km/h ± 1.72 km/h), which was significant (p < .001, d = -1.19). HR estimated by the watch at LT was 1,72% lower (p > .05). LT data obtained in the field test showed greater overall variance.

Conclusion

Our results suggest sufficient accuracy of Fenix 7® LT estimates for recreational athletes. It can be assumed that for professional athletes, it would fail to provide the nuanced data needed for high-quality training management.

References

Cheng, B., Kuipers, H., Snyder, A., Keizer, H., Jeukendrup, A., & Hesselink, M. (1992). A new approach for the determination of ventilatory and lactate thresholds. International Journal of Sports Medicine, 13(7), 518–522. https://doi.org/10.1055/s-2007-1021309

Published
23.09.2024
How to Cite
Schlie, J., Heiber, M., Schittenhelm, A., Beckert, M., Graf, P., & Schmidt, A. (2024). Garmin Fénix 7® underestimates performance at the lactate threshold in comparison to standardized blood lactate field test. Current Issues in Sport Science (CISS), 9(4), 056. https://doi.org/10.36950/2024.4ciss056
Issue
Vol. 9 No. 4 (2024): Embracing Interdisciplinarity in Sport Science. 19th Congress of the Austrian Sport Science Society (ÖSG) in Innsbruck, Austria. Book of Abstracts
Section
Oral and poster presentations

License

Copyright (c) 2024 Jennifer Schlie, Marie Heiber, Andrea Schittenhelm, Marcus Beckert, Pascal Graf, Annette Schmidt

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.