There are no exact equation but you can estimate it from skill values. For example, you train a player by Carioca drill that evolves aggression and speed skills with value a and b. You can figure out the gain by the average of these skill values: x = 180 - (a+b)/2. In my experience, if x >80, the gain is big. In that case your FT player should gain one SA point each 11 or 12% condition loss.