Hi,
I suggest starting with the ANT+ Heart Rate Monitor (HRM) and Stride Based Speed and Distance Monitor (SDM) device profiles in the "ANT+ Member Zone". These device profiles specify the requirements for transmitting and receiving HRM and SDM data.
Also, you can download the "ANT_Windows_Library_Package". This package contains demos (.Net windows applications) that show how to configure an ANT channel, transmit and receive data.
Good luck in developing your application!