As previously discussed, running injuries can arise from overuse and overtraining. It is important to understand the best parameters for improving our speed and endurance as well as preventing injuries. This is where the 80/20 rule comes into play.
The 80/20 rule states that 80% of your weekly runs should be completed at a low to moderate intensity whilst the remaining 20% should be at moderate to high intensities.
Whilst completing your runs, the best ways to measure your intensity are heart rate, pace per mile/km or perceived rate of exertion.
Why are the two intensities good to work at?
Recruits more fast-twitch muscle fibers (provides power)
Boost blood vessel elasticity
Increase heart strength and increase pain tolerance
However, at high intensities the fast twitch fibers burn through glucose creating lactate which can inhibit muscle contraction and slow you down.
Increases the growth of mitochondria which helps burn fat efficiently and decrease soreness and fatigue
Research has shown that increasing your training volume can reduce your risk of injury in the long run, however the increase needs to be slow and gradual.
If you are interested in starting long distance running here is a resource to provide you with more information.
It is important to note this rule does not just apply to running but any endurance events i.e swimming, cycling, triathlon