Basal metabolic rate be elevated in stress, illness, and diabetes. Menopause may also affect metabolism. Heart rate is determined by the medulla oblongata and part of the pons, two organs located inferior to the hypothalamus on the brain stem. Heart rate is important for basal metabolic rate and resting metabolic rate because it drives the blood supply, stimulating the Krebs cycle. During exercise that achieves the anaerobic threshold, it is possible to deliver substrates that are desired for optimal energy utilization. The anaerobic threshold is defined as the energy utilization level of heart rate exertion that occurs without oxygen during a standardized test
Heart rate turbulence normal cardiac cycle, so the ventricles of the heart haven't had time to fill up to their normal level, before contracting and pumping their contents out. This results in a pulse (blood pressure) weaker than expected and triggers normal homeostatic mechanisms that try to compensate by constricting arteries and increasing heart rate (the turbulence onset part of HRT). This is accomplished by the brain reflexively withdrawing the parasympathetic nerve signals and increasing the sympathetic nerve signals it sends to the heart. The compensatory constriction of the arteries and increased heart rate frequently cause blood pressure to oveshoot normal values (overcompensates),