Percent heart rate reserve calculated using resting heart rate during sleep showed a non-significant mean difference of 1.7% compared to the gold standard percent oxygen consumption reserve.
Cross-Sectional (n=12)
No
Is percent heart rate reserve calculated using resting heart rate during sleep a valid measure of exercise intensity compared to percent oxygen consumption reserve?
Using resting heart rate during sleep provides a valid, calibration-less method to calculate exercise intensity (%HRR) using wearable devices.
Effect estimate: Mean difference 1.7% (95% CI -0.2 to 3.6%)
p-value: p=0.2552
Abstract Background The recent development of wearable devices has enabled easy and continuous measurement of heart rate (HR). Exercise intensity can be calculated from HR with indices such as percent HR reserve (%HRR); however, this requires an accurate measurement of resting HR, which can be time-consuming. The use of HR during sleep may be a substitute that considers the calibration-less measurement of %HRR. This study examined the validity of %HRR on resting HR during sleep in comparison to percent oxygen consumption reserve (%VO 2 R) as a gold standard. Additionally, a 24/7%HRR measurement using this method is demonstrated. Methods Twelve healthy adults aged 29 ± 5 years underwent treadmill testing using the Bruce protocol and a 6-min walk test (6MWT). The %VO 2 R during each test was calculated according to a standard protocol. The %HRR during each exercise test was calculated either from resting HR in a sitting position (%HRR sitting ), when lying awake (%HRR lying ), or during sleep (%HRR sleeping ). Differences between %VO 2 R and %HRR values were examined using Bland-Altman plots. A 180-day, 24/7%HRR measurement with three healthy adults was also conducted. The %HRR values during working days and holidays were compared. Results In the treadmill testing, the mean difference between %VO 2 R and %HRR sleeping was 1.7% (95% confidence interval CI, − 0.2 to 3.6%). The %HRR sitting and %HRR lying values were 10.8% (95% CI, 8.8 to 12.7%) and 7.7% (95% CI, 5.4 to 9.9%), respectively. In the 6MWT, mean differences between %VO 2 R and %HRR sitting , %HRR lying and %HRR sleeping were 12.7% (95% CI, 10.0 to 15.5%), 7.0% (95% CI, 4.0 to 10.0%) and − 2.9% (95% CI, − 5.0% to − 0.7%), respectively. The 180-day, 24/7%HRR measurement presented significant differences in %HRR patterns between working days and holidays in all three participants. Conclusions The results suggest %HRR sleeping is valid in comparison to %VO 2 R. The results may encourage a calibration-less, 24/7 measurement model of exercise intensity using wearable devices. Trial registration UMIN000034967 . Registered 21 November 2018 (retrospectively registered).
Matsuura et al. (Mon,) conducted a cross-sectional in Healthy (n=12). Percent heart rate reserve using sleeping resting heart rate (%HRRsleeping) vs. Percent oxygen consumption reserve (%VO2R) was evaluated on Mean difference between %VO2R and %HRRsleeping during treadmill testing (Mean difference 1.7%, 95% CI -0.2 to 3.6%, p=0.2552). Percent heart rate reserve calculated using resting heart rate during sleep showed a non-significant mean difference of 1.7% compared to the gold standard percent oxygen consumption reserve.