Heart rate persons with coronary artery disease. The heart rate is rhythmically generated by the sinoatrial node. It is also influenced by central factors through sympathetic and parasympathetic nerves. Nervous influence over the heartrate is centralized within the two paired cardiovascular centres of the medulla oblongata. The cardioaccelerator regions stimulate activity via sympathetic stimulation of the cardioaccelerator nerves, and the cardioinhibitory centers decrease heart activity via parasympathetic stimulation as one component of the vagus nerve. During rest, both centers provide slight stimulation to the heart, contributing to autonomic tone. This is a similar concept to tone in skeletal muscles. Normally, vagal stimulation
Heart rate error, S = 7–11 bpm. Consequently, the estimation calculated by HR = 220 − age has neither the accuracy nor the scientific merit for use in exercise physiology and related fields. A 2002 study of 43 different formulas for HR (including that of Haskell and Fox – see above) published in the Journal of Exercise Psychology concluded that: Research conducted at Northwestern University by Martha Gulati, et al., in 2010 suggested a maximum heart rate formula for women: A 2008 study from Lund, Sweden gives reference values (obtained during bicycle ergometry) for men: and for women: Maximum heart rates vary