I have a ride file parsing application that parses a ride file into categories based on a training schema (e.g., Andy Coggan's levels or Ric Stern's ranges). Classification criteria are based on intensity (power) and duration. AP or NP can be used for the intensity criteria for any level from 5mins+, AP for efforts <5mins. The criteria are pretty well defined with the exception of L6 versus L7. My question is, "At what intensity does an effort become primarily a NM effort?" For example, when I am fit my FTP is about 300W. My max 5sec power varies from about 900W if I haven't done any L7s to about 1200W if I have been doing L7s regularly. So, should I count only efforts >900W as NM efforts? Or, is a 750W effort primarily NM? What about 600W efforts? I think I'm leaning toward something like 200%FTP as a general rule. What do you think?