visualizing training efforts

I guess we all read training books and running magazines once in a while. Some time ago I was stumbling over the concept of calculating training efforts. This is done because people should avoid a situation where the training becomes a kind of routine causing the body to stop adapting. How to judge and calculate the training effort? Judging the training can be done by scaling the felt effort lets say on a 1-10 scale where 1=easy stroll and 10=staying close to Gerald on the track ;-). This is a wide range and I decided to categorize the running speed into 4 groups only instead: >5:30=1; 5:30-4:30=1,5; 4:30-3:50=2; <3:50=3.>This means that a 30k long run at 5:30 would result in an Intensity of I(LDL)=30*1=30. A 10k tempo run at 3:45 pace would result in the same intensity since I(tempo run)=10*3. Simply put, this calculation is the mathematical way of saying: "A hard day should always be followed by an easy day". I use Intensity and effort as synonyms here. Well, looking at the chart we can see that the VIC training gives a lot of variation to the training. Once a week, the long run demands the highest work out load followed by the interval training on the track.