I appreciate this is where it gets quite hard in software, but I thought I'd throw the idea around to see what people think.
Bernard Hinault, 5 time Tour de France winner and oft overlooked cycling legend used to apply a basic scoring system to his training. This was for motivation and to help balance his training load. Now on Tri blogs - if you have a coach putting a plan in for you, these kind of things are probably taken into account and wouldn't necessarily be needed. However for a solo athlete recording and monitoring their own training it can be a crude but effective tool. How you'd do it in Triblogs I'm not sure.
Here's the idea
BH decided that there was a minimum amount of training he had to do to be a) fit, b) competitive or c) winning races (I can hear the alarm claxens going off from some coaches already but stick with it). Basically determine the training you want/need/would like to do and convert this into points based on duration and/or intensity. When you do a session you score points e.g. 30 minutes at steady pace = 30 points. 30 minutes high intensity = 90 points ideally you create the scoring system based on your own criteria. If you record the points you score for each session you can then start to measure this against what you wanted to do etc. So you can start to identify if you are not doing as much training as you want to (below your projected point score) or too much training (above your predicted point score) in which case ease off etc.
What it would require in triblogs would be the ability to match (your own) scores to each of the intensity levels 60-70%, 70-80% etc, then have a calculated field that multiplies this score by your duration to give you a session score. Looking further from this you could have alerts programmed in that were based on your planned accumulated score. These could then fire off if you go a certain % over or under target. Ignoring the BH points philosophy for a moment, this could also be useful based on a time basis i.e. if triblogs said 36 hours is too much training for one week you nutter” or “you aren't gonna get under 2:15 in a standard distance sitting on your backside all week well... maybe the same sentiments but slightly better worded....
As I mentioned, the points system is fairly crude, probably needs more explanation, and probably isn't for everyone, but it can be quite useful and motivational for target driven individuals (does this describe any triathletes you know?). Although probably a little tricky to incorporate from a programming perspective.
Had 10 minutes spare so thought I'd mention it....