I had learnt to run most of my runs slow and that is how I became faster.
Today, my weekly training compromise of 70-80% slower runs.
Running most of my runs slow has allowed my body time to improve my aerobic energy system that helps to greatly improve my stamina.
Slow runs also decrease chances of injuries and had enabled me to get more out of my harder running days, because there will be less residual fatigue, and enables me to increase my overall weekly mileage as I progress with your training.
My slow run pace is normally around 1-2 minutes away from my race pace, but it varies from runner to runner. So if you are a beginner to running, do always focus on building mileage first instead of speed. Lots of runners want to start out fast, end up getting hurt and gave up running altogether.
Chalk up the miles first with slower runs, build up your aerobic capacity first and then we talk about speed.
Here is the video of one of my slow run days. Enjoy!