How Accurate is the Fitbit Alta and Alta HR? Unlike other reviews that barely scratch the surface with opinion-based info, this review digs deeper into the evolution of fitness trackers to provide a robust analysis of their true accuracy. Jump ahead to 1:54 to skip the history and jump into the accuracy issues. For the bottom line (Spoiler Alert!) skip all the way to 4:49. But doing so, you'll miss the point entirely. so be sure to go back and watch the entire video to put it all in perspective.