What is junk mileage?
Junk mileage is a hotly debated subject amongst the running community with many runners believing that ‘junk mileage’ is actually slow running.
In fact junk mileage is actually running at a speed that is not hard enough for aerobic or speed development (such as tempo pace) yet not easy enough to recover between hard sessions.
One way to reduce your risk of running too many junk miles is wearing a heart rate monitor in training. There is a vast difference between perceived effort and actual effort for a lot of athletes.
Utilising heart rate training to avoid training in the ‘grey zone’ (aka junk mileage) is an effective way to ensure you’re training in the right zones and managing the cortisol response from training, and improving your performance.
I will write more about cortisol in due course but simply put cortisol is a hormone produced in the adrenal glands. It can build you up or be the reason why you come crashing down at speed. Too much stress from training can chronically elevate your cortisol levels leaving you feeling tired and over trained.
