Relationships between 24-hour diet and autonomic markers of heart rate of badminton players

Abstract

Despite proof that diet may influence heart rate variability (HRV) and heart rate recovery (HRR)) as indicators of the autonomic nervous system (ANS) activation, no researchers have investigated the influence of a normal short-term in-competition diet on the real-life competition HRV and HRR of participants. Therefore, the objectives of this study were first, to determine the relationships between 24-hour diet and pre-, in-, and post-match HRV of badminton players; and, secondly, to determine the relationships between a 24-hour diet and the in- and post-match HRR of badminton players. To fulfil the above-mentioned objectives, the HRV and HRR of 22 male, African, singles badminton players (age: 23.3 ± 3.9 years; height: 177.1 ± 3.0 cm; mass: 83.4 ± 14.5 kg) were measured before, during, and directly after 46 badminton matches using fixed Polar HR transmitter belts and monitors. A 24-hour diet recall questionnaire in an interview format was used to estimate the dietary intake of participants’ normal in-competition days. Results of cluster analyses reduced diet-related variables were canonically correlated to the pre-match, in-match, and post-match HRV as well as in-match and post-match HRR parameters of participants. The level of significance was set at p ≤ 0.05. For the first objective of the study, canonical correlations of the respective relationships between the macronutrient, micronutrient, and HRV parameters over the different match periods, showed significant values (p = 0.0000-0.03), except for the canonical correlation (Rc = 0.97, p = 0.105) between the 24-hour in-competition macronutrient intake and the post-match HRV-related variables of the badminton players. Results further revealed that trans-fatty acids and available carbohydrates (CHO) were the macronutrients that had the greatest influence on changes in HRV parameters over the different match periods. In addition, calcium, potassium, vitamin D, and boron were identified as the micronutrients with the biggest influence on changes in participants’ pre-match HRV. Calcium was the only micronutrient that had a meaningful influence on HRV changes during the in-match period, whereas potassium had the most influence on post-match HRV changes. For the second objective of the study, the canonical correlation for the relationship between micronutrient components, and the in- and post-match HRR-related variables of participants

showed a significant value (R = 0.92 p = 0.03), whereas the relationship between macronutrients, and the in- and post-match HRR of participants were non-significant (R = 0.84, p = 0.10). Results further revealed that available CHO, total sugars, added sugars, as well as trans-fatty acids, were the macronutrients with the biggest influence on changes in HRR-related variables over the two match periods. Finally, vitamin D, calcium, and potassium were the micronutrients that contributed meaningfully to changes in participants’ in- and post-match HRR. To the knowledge of the researcher, this is the first study of its kind to investigate the influences of dietary intake on the parameters of ANS during a real-life badminton competition. Study results showed that badminton players’ HRV and HRR during different periods of a real-life badminton competition were influenced by the intake of various diet components (macro and micronutrients). Therefore, the results highlight the importance of managing athletes' in-competition diets to ensure optimal functioning of the ANS during competition participation.