Normative data on heart rate variability have been collected.176-178 This technology appears to hold promise for assessing overall fitness. Gallagher et al179 compared age matched groups with different lifestyles. These were smokers, sedentary persons, and aerobically fit individuals. They found that smoking and a sedentary lifestyle reduces vagal tone, whereas enhanced aerobic fitness increases vagal tone. Dixon et al180 reported that endurance training modifies heart rate control through neurocardiac mechanisms.
In occupational health, the effects of various stresses of the work environment of heart
patients and asymptomatic workers may be evaluated using heart rate variability
analysis. care. 181 182,183
Heart rate variability has been shown to be responsive to chiropractic
_________________________________________________________ Council on Chiropractic Practice Clinical Practice Guideline Number 1 Vertebral Subluxation in Chiropractic Practice – 2003 Update & Revision