Recovery Index or RI is a numeric measure of the Rusko HR curve and is used by some Canadian teams to quantify the recovery value of the Rusko Heart Rate test.
Training Index or TI is calculated by multiplying different Zones of training by factors so at to get a quantitative measure of the difficulty of a day's training. For example Zone1 hrs are multiplied by 1, whereas Zone4 hrs are multiplied by 7. You can edit the TI value for each Zone and specify your own TI values for custom Zones. You can chart the TI value on the Year Chart overtop of the regular Hours data.