Effects of Intermittent Fasting on Heart Rate Variability in Male Wistar Rats

Introduction. In the wild, rodents do not have constant access to food and are forced to constantly search for it. These conditions are analogous to a feeding regimen known as "intermittent fasting". Studying cardiac function and electrocardiogram parameters under conditions of limited food access will allow us to investigate the features of autonomic nervous system functioning in rats under near-natural conditions

Materials and Methods. The study used an intermittent fasting model, in which animals in the experimental group (n=7) were given access to food for one hour daily for 4 days, while control animals (n=7) were kept ad libitum. After the end of the intermittent fasting period, ECG recording was performed to calculate heart rate variability indicators for 3 minutes in order to analyze the state of the sympathetic and parasympathetic circuits of the autonomic regulation of the heart.

Results. Statistical analysis revealed a decrease in AMO and SI parameters and an increase in SD and RMSSD parameters in male Wistar rats 24 hours after the end of intermittent fasting. This simultaneous change in these parameters indicates a weakening of the sympathetic regulation of cardiac function and activation of the parasympathetic circuit.

Study limitations. The study aims to elucidate the visceral functions and behavioral responses of rodents when changing their diet and is of interest to pest control specialists.

Conclusion. intermittent fasting for 4 days with feeding during the day in rats leads to an increase in tonic parasympathetic influences on the functioning of the heart.

Ethics approval. The study was approved by the Ethics Committee of the Disinfectology Institute of “FSCH named after F.F. Erisman” of Rospotrebnadzor" (№. 2¹, 06.05.2025), conducted in accordance with the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (ETS N 123), the Directive of the European Parliament and the Council of the European Union.

Contribution:
Manchenko D.M. — collection of materials; data processing, writing the text;
Glazova N.Yu. — collection of materials; data processing;
Khirazova E.E. — editing;
Komarov V.Yu. — editing.
All co-authors — approval of the final version of the article, responsibility for the integrity of all parts of the article.

Funding source. This study was not supported by any external sources of funding.

Conflict of interest. The authors declare no apparent or potential conflicts of interest related to the publication of this article.

Received: 09.02.2026 / Accepted: 22.07.2026 / Published: 10.08.2026

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