Calorie restriction regime enhances physical performance of trained athletes

Abstract

Background

Caloric restriction induces mitochondrial biogenesis and improves physical fitness in rodents. We aimed to provide evidence of how caloric restriction affects the body composition and physical performance of trained athletes and to evaluate the possible impact of an every-other-day feeding diet on nutritional deficiencies of micronutrients and essential fatty acids.

Methods

The study was performed with 12 healthy male athletes by carrying out a 33% caloric restriction with respect to their usual diet. Athletes performed a maximal exercise stress test both before and after the caloric restriction period. Blood samples were taken before and after the caloric restriction at basal conditions and 30 min post-exercise. Although energy intake was reduced by about 33%, the contribution of carbohydrates, proteins, and lipids to total energy intake during the caloric restriction was similar to the original diet.

Results

The caloric restriction reduced the daily specific micronutrient intake to values lower than 90% of recommended dietary allowances. No effects were observed in blood parameters related to iron metabolism and tissue damage, glucose levels, lipid profiles, or erythrocyte fatty acid composition. In addition, oxidative damage markers decreased after the nutritional intervention. The caloric restriction intervention significantly reduced body weight and trunk, arm, and leg weights; it also caused a decrease in fat and lean body mass, the energy expenditure rate when performing a maximal exercise stress test, and the energy cost to run one meter at various exercise intensities. Furthermore, the intervention ameliorated the onset of the anaerobic phase of exercise.

Conclusion

A caloric restriction improves athletes’ performance and energy efficiency, but reduces the daily intake of micronutrients; so, when caloric restriction programs are implemented micronutrient supplementation should be considered.

Trial registration

The project was registered at ClinicalTrials.gov (NCT02533479).

Keywords:

• Caloric restriction
• Physical performance
• Fatty acids
• Body composition

Funding

Acción Estratégica en Salud del Ministerio de Ciencia e Innovación DPS2008–07033-C03–03, Programme of Promotion of Biomedical Research and Health Sciences, Projects 11/ 01791, Red Predimed-RETIC RD06/0045/1004, CIBEROBN CB12/03/30038 and Balearic Island Government and FEDER funds (35/2011 and 23/2012). We hereby acknowledge the PhD grant provided by the University of the Balearic Islands.

Availability of data and materials

Please contact author for data requests.

Authors’ contributions

VP, JR, XC, MM, AS, JAT, FD and AP conception and design of research; VP, JR, XC, and MM, performed experiments; VP, JR, XC, MM, AS and FD analysed data; VP and MM interpreted results of experiments; VP, JR, MM drafted manuscript; JR, AS, MM, JAT, FD and AP edited and revised manuscript; JR, XC, MM, AS, FD, JAT, and AP approved final version of manuscript. All authors read and approved the final manuscript.

Ethics approval and consent to participate

All of the participants were informed of the purpose and demands of the study before providing their written consent to participate. The protocol complied with the Declaration of Helsinki for research on human subjects and was approved by the Clinical Research Ethics Committee at the Direcció General de l’Esport of the Catalonian Sports Council.

Consent for publication

All the study participants gave their consent to publish the research findings.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.