Validity of the ithleteTM Smart Phone Application for Determining Ultra-Short-Term Heart Rate Variability

Abstract

The purpose of this investigation was to cross-validate the ithlete™ heart rate variability smart phone application with an electrocardiograph for determining ultra-short-term root mean square of successive R-R intervals. The root mean square of successive R-R intervals was simultaneously determined via electrocardiograph and ithlete™ at rest in twenty five healthy participants. There were no significant differences between the electrocardiograph and ithlete™ derived root mean square of successive R-R interval values (p > 0.05) and the correlation was near perfect (r = 0.99, p < 0.001). In addition, the ithlete™ revealed a Standard Error of the Estimate of 1.47 and Bland Altman plot showed that the limits of agreement ranged from 2.57 below to 2.63 above the constant error of −0.03. In conclusion, the ithlete™ appeared to provide a suitably accurate measure of root mean square of successive R-R intervals when compared to the electrocardiograph measures obtained in the laboratory within the current sample of healthy adult participants. The current study lays groundwork for future research determining the efficacy of ithlete™ for reflecting athletic training status over a chronic conditioning period.

A comparison of two methods of heart rate variability assessment at high altitude

“…However, traditional HRV assessments require at least five minutes of data recording, are more expensive and provide a plethora of highly complex time and frequency domain derived data undermining their applicability for everyday use. The ithlete™ circumvents these issues by providing an easy to understand intuitive RMSSD derived HRV reading obtained over 55 seconds which can be recorded to a mobile phone or portable tablet (Flatt and Esco., 2013). In the only previous comparative study to compare the ithlete™ to a reference HRV device a near perfect correlation between the ithlete™ and a five minute electrocardiography HRV device was observed in 25 healthy subjects at sea level (r = 0.99, p < 0.001) (Flatt and Esco 2013).…”

“…The ithlete™ circumvents these issues by providing an easy to understand intuitive RMSSD derived HRV reading obtained over 55 seconds which can be recorded to a mobile phone or portable tablet (Flatt and Esco., 2013). In the only previous comparative study to compare the ithlete™ to a reference HRV device a near perfect correlation between the ithlete™ and a five minute electrocardiography HRV device was observed in 25 healthy subjects at sea level (r = 0.99, p < 0.001) (Flatt and Esco 2013). On Bland Altman analysis the level of agreement was -2.57 to 2.63 above the constant bias (constant error) of -0.03.…”

“…All subjects were seated, wearing warm clothing in a tent for at least 5 minutes before the HRV recordings were obtained (Flatt et al 2013). HRV variability was obtained using the ithlete™ (HRV Fit Ltd.…”

“…All ithlete™ HRV data was collected with the ithlete™ ECG receiver and ithlete™ application on the subjects apple smart phone as previously described (Flatt and Esco 2013). Two 55 second recordings were obtained with the ithlete during the first and last minute of a five minute HRV recording obtained by a CheckMyHeart™ device.…”

The Effects of Heart Rate Versus Speed-Based High-Intensity Interval Training on Heart Rate Variability in Young Females

“…15 However, while it has been shown that ultra-short-time Ln rMSSD, is sensitive to team sport training interventions, 16 the differences between the effects of different HIT protocols on this marker have yet to be determined. Following these lines, there seems to be a lack of evidence on differences between the effects of HR-based and speed-based HIT interventions on ultra-short-time Ln rMSSD in the literature.…”