ACCURACY OF THE KARVONEN FORMULA IN A LARGE HETEROGENEOUS POPULATION

The Karvonen heart rate (HR) reserve formula has been used extensively to estimate the HR associated with a given %VO2max. However, there have been no studies with a large heterogeneous population to determine if this formula is accurate. Therefore, 663 subjects in the HERITAGE Family Study with complete data and a wide range of initial VO2max values were classified by age (17–29, 30–49, and 50–65 years), sex (male and female), race (black and white) and also grouped by their initial VO2max levels (ml/kg/min). Regression equations for HR to VO2 were calculated for each subject. HRs at 30%–100% VO2max were estimated from each regression equation. Using a paired t-test with significance set at 0.01, mean HRs at each %VO2max were compared with HRs estimated by the Karvonen formula. Women had higher resting (RHR) and higher submaximal HRs than men but their HRmax was not different. With increasing age, RHR was similar but HRmax decreased. There were no differences between blacks and whites for RHR or HRmax. For all subjects, for both sexes, for both races, for the 3 age groups and for the subjects grouped by their initial VO2max, there was a significant increase in VO2max and a significant decrease in HR at the same absolute VO2 (ml/min) after training but there was no difference in HR at the same %VO2max. The Karvonen formula gave higher estimates of HR at the same %VO2max (12–17, 9–14, 6–9 and 0–6 beats/min higher at 30%, 50%, 70% and 90% VO2max, respectively). It is concluded that the Karvonen formula is not accurate before and after training in a large heterogeneous population of men and women, blacks and whites of different ages and initial levels of fitness. Supported by NIH-NHLBI grants