What is a normal heart rate?
Disassembling the myth that the normal range for the resting heart rate is 60-100.

REFERENCES

Maximum predicted HR:
Robergs R, Landwehr R. The surprising history of the “HRmax = 200-age” equation. Journal of Exercise Physiology online. 2002; 5:1-10.
https://www.asep.org/asep/asep/Robergs2.pdf

Fetal HR:
DuBose TJ. Embryonic heart rates. Fertil Steril. 2009; 92:e57.
http://www.ncbi.nlm.nih.gov/pubmed/19748085

Evidence for normal heart rate range:
Mason JW, et al. Electrocardiographic reference ranges derived from 79,743 ambulatory subjects. J Electrocardiol. 2007; 40:228-34.
http://www.ncbi.nlm.nih.gov/pubmed/17276451

Survey of cardiologists about defining normal sinus rhythm:
Spodick DH. Survey of selected cardiologists for an operational definition of normal sinus heart rate. Am J Cardiol. 1993; 72:487-8.
http://www.ncbi.nlm.nih.gov/pubmed/8352202

History of “normal sinus rhythm”:
Dolgin M. Normal sinus rhythm. Am J Cardiol. 1993; 71:496-7.
http://www.ncbi.nlm.nih.gov/pubmed/8430659

Kossmann CE. The normal electrocardiogram. Circulation. 1953;920-36.
http://www.ncbi.nlm.nih.gov/pubmed/13106913

Spodick DH. Is there such a thing as normal sinus rate? Br Heart J. 1993;486-7.
http://www.ncbi.nlm.nih.gov/pubmed/8260287

HR and mortality following a myocardial infarction:
Hjalmarson A, et al. Influence of heart rate on mortality after acute myocardial infarction. Am J Cardiol. 1990;65:547-53.
http://www.ncbi.nlm.nih.gov/pubmed/1968702

HR and mortality among all adults:
Aladin A, et al. Relation of resting heart rate to risk for all-cause mortality by gender after considering exercise capacity (the Henry Ford exercise testing project). Am J Cardiol. 2014; 114:1701-6.
http://www.ncbi.nlm.nih.gov/pubmed/25439450

General background on the topic of normal HRs:
Spodick DH. Redefinition of normal sinus heart rate. Chest. 1993; 104:939-41.
http://www.ncbi.nlm.nih.gov/pubmed/8365314