Influence of Short-Term Fasting on the Changes in Women’s Cardiovascular Functional Parameters

Abstract

Research background and hypothesis. Recently, cardiovascular diseases (CVD) have been the major cause
of mortality as a result of poor diet, emotional stress and insuffi cient physical activity. Improvement of dietary
habits based on reduction of body weight by short-term or long-term fasting has been observed. While analyzing
the effect of fasting, its psychological rather than physiological features are usually emphasized.
Research aim was to assess the impact of daily fasting on the changes in women’s cardiovascular functional
parameters during physical load.
Research methods. Thirty six women performed exercise test on bicycle ergometer (the load increased each
minute by 25 W) before and after 24 hours of fasting. After the 1 st  exercise test the subjects used only non-energetic
liquid. Evaluation of electrocardiogram (ECG) data was performed applying computerized ECG analysis system
“Kaunas–Load“(Institute of Cardiology, LUHS). We analyzed systolic blood pressure (S), heart rate (HR) and
JT interval at rest and throughout the load.
Research results. After 24 hours of fasting, HR of women at rest and during the fi rst 3 minutes of the load
signifi cantly decreased (p < 0.05). Duration of the JT interval decreased during both exercise tests. Longer JT
interval was obtained at rest and during the fi rst 2 minutes of the load after 24 hours of fasting (p < 0.05). S at
rest and throughout the load was signifi cantly lower after fasting (p < 0.05).
Discusion and conclusions. Functional state evaluation of untrained women after 24 hours of fasting during
bicycle ergometery test demonstrated dynamical changes of many cardiovascular function variables: lower HR,
increased the JT interval, and decreased S.

Keywords: cardiovascular system, short-term fasting, bicycle ergometer test.