1 Does electrical stimulation to the hands (transcutaneous electroacupuncture stimulation, TEAS) have frequency‐specific effects on heart rate variability (HRV)? David Mayor, a, 1 Tony Steffert, a, b Deepak Panday, a Aiste Noreikaite, a Lidia Zaleczna b a. University of Hertfordshire; b. Open University. Contents Background p. 2 Methods p. 4 Measures used p. 5 1. General indices 2‐3. Time‐domain parameters 4. Frequency‐domain parameters 5. Nonlinear measures Statistical methods p. 7 Analysis and results p. 8 HRV measures: values found The meaning of the measures 1. Which measures most strongly reflected differences between the various stimulation frequencies? p. 10 1.1. How much do the HRV measures vary in themselves? 1.2. Some sample graphs and their interpretation p. 11 1.3. Which particular HRV measures showed significant differences between the stimulation frequencies? p. 16 2. Which measures most reflected changes during and after stimulation? p. 17 2.1. Comparing effect sizes (ESs) 1 Corresponding author: davidmayorwelwynacupuncture.co.uk