https://www8.garmin.com/support/download_details.jsp?id=7627
Change History
Changes made from version 6.11 to 6.13:
Added support for the latest running dynamics. These include: Ground Contact Time Balance, Stride Length, and Vertical Ratio (requires a new HRM-Run, the original HRM-Run with sw ver 6.60, or HRM-Tri with sw ver 4.20).