Validity of the ithleteTM Smart Phone Application for Determining Ultra-Short-Term Heart Rate Variability Posted on December 26, 2013 by hrvtraining 3 Here’s our latest study testing the accuracy of the ithlete vs ECG. “Validity of the ithleteTM Smart Phone Application for Determining Ultra-Short-Term Heart Rate Variability” Share this:TwitterFacebookLinkedInTumblrEmailPrintRedditPinterestLike this:Like Loading...