The Pareto principle

The Pareto Principle, or the Law of the Vital Few, tells us that: for many events roughly 80% of the effects come from 20% of the causes.

Today was the 80% mark in Janathon 2013. Most of my running so far this month has been junk miles: many short sessions, usually at a slow pace, often focused primarily on hazard avoidance (dark, snow, ice, traffic) rather than on specific training objectives.

Applying the Pareto principle, if all of my runs in this last 20% of the month are high quality, then I can still accrue 80% of the total training benefit.