Impact of Equation Choice on Resting Metabolic Rate Ratio in High-Level Men and Women Athletes

Abstract

Objective

To examine the impact of the RMR ratio cutoff point selected on the categorization of prevalence/absence of low energy availability among predictive equations in high-level athletes (n = 241 [99 women]; 52% competed at the World Championship and Olympic Games), and whether this categorization is influenced by sex and the predictive equation used.

Methods

We assessed RMR using indirect calorimetry, predicted the RMR using the equations proposed by Harris-Benedict, FAO/WHO/UNU, de Lorenzo, ten Haaf and Wejis, Wong, Jagim, Cunningham, and Freire, and computed the RMR ratio for each equation.

Results

We observed that the cumulative percentage of RMR ratio values increased at a faster rate using Jagim, ten Haaf and Wejis, and Cunningham equations compared to the other equations. At the 0.90 value (the most used cutoff point in literature), the Jagim equation categorized ≥ 50% of the athletes into “low energy availability”. No Sex × Equation × Sport interaction effect was observed (F = 0.10, p = 1.0). There was a significant main effect to Sex (F = 11.7, p < 0.001, ES = 0.05), Sport (F = 16.4, p < 0.001, ES = 0.01), and Equation (F = 64.1, p < 0.001, ES = 0.19). Wong and FAO/WHO/UNU equations yielded the largest errors (assessed vs. predicted RMR) in men and women, respectively.

Conclusion

The selected RMR ratio cutoff point influences the prevalence/absence of low energy availability characterization in high-level athletes and suggests that certain equations could bias its assessment.

Keywords:

• Energy expenditure
• energy expenditure
• metabolism
• energy needs

Acknowledgements

The authors would like to thank all the athletes who volunteered for this investigation.

Author contributions

All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Raul Freire, Matheus Hausen, and Alex Itaborahy. The first draft of the manuscript was written by Juan Manuel A Alcantara, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

JMAA is supported by a Juan de la Cierva Formación postdoctoral grant (Grant FJC2020-044453-I) funded by MCIN/AEI/10.13039/501100011033 and by “European Union NextGenerationEU/PRTR”.