Validation of Heart Rate Monitor-Based Predictions of Oxygen Uptake and Energy Expenditure

Montgomery, PG, Green, DJ, Etxebarria, N, Pyne, DB, Saunders, PU, and Minahan, CL. Validation of heart rate monitor-based predictions of oxygen uptake and energy expenditure. J Strength Cond Res 23(5): 1489-1495, 2009-To validate &OV0312;o2 and energy expenditure predictions by the Suunto heart rate (HR) system against a first principle gas analysis system, well-trained male (n = 10, age 29.8 ± 4.3 years, &OV0312;o2 65.9 ± 9.7 ml·kg−1·min−1) and female (n = 7, 25.6 ± 3.6 years, 57.0 ± 4.2 ml·kg−1·min−1) runners completed a 2-stage incremental running test to establish submaximal and maximal oxygen uptake values. Metabolic cart values were used as the criterion measure of &OV0312;o2 and energy expenditure (kJ) and compared with the predicted values from the Suunto software. The 3 levels of software analysis for the Suunto system were basic personal information (BI), BI + measured maximal HR (BIhr), and BIhr + measured &OV0312;o2 (BIhr + v). Comparisons were analyzed using linear regression to determine the standard error of the estimate (SEE). Eight subjects repeated the trial within 7 days to determine reliability (typical error [TE]). The SEEs for oxygen consumption via BI, BIhr, and BIhr + v were 2.6, 2.8, and 2.6 ml·kg−1·min−1, respectively, with corresponding percent coefficient of variation (%CV) of 6.0, 6.5, and 6.0. The bias compared with the criterion &OV0312;o2 decreased from −6.3 for BI, −2.5 for BIhr, to −0.9% for BIhr + v. The SEE of energy expenditure improved from BI (6.74 kJ) to BIhr (6.56) and BIhr + v (6.14) with corresponding %CV of 13.6, 12.2, and 12.7. The TE values for &OV0312;o2 were ∼0.60 ml·kg−1·min−1 and ∼2 kJ for energy expenditure. The %CV for &OV0312;o2 and energy expenditure was ∼1 to 4%. Although reliable, basic HR-based estimations of &OV0312;o2 and energy expenditure from the Suunto system underestimated &OV0312;o2 and energy expenditure by ∼6 and 13%, respectively. However, estimation can be improved when maximal HR and &OV0312;o2 values are added to the software analysis.