The term ‘junk miles’ refers to any steady to moderate paced running that a runner does over the course of a week which doesn’t have a specific physiological target to meet a desired outcome - i.e. to smash your 10k PB or complete your first marathon
There’s an argument that there’s no such thing as ‘junk miles’ because of the huge benefits that running brings to our physical and mental health. But if you’re training for a specific goal such as completing a marathon or beating your 5k PB, then it’s important that your run training is specific in helping you to achieve that goal.
Runners who advocate a high-mileage philosophy of training believe that training volume is the most important characteristic of an effective training program i.e. ‘the more miles you run, the better’. But this approach can rack up a lot of ‘junk miles’ or wasteful extra running on top of the key sessions they need to do to improve their running fitness. And in some cases it can lead to ‘overtraining’ which is when a runner exceeds their body's ability to recover from strenuous exercise and therefore has a detrimental effect on their performance and injury.
Also running high mileage at the same pace can make it difficult to make gains in speed because during a long run, a runner is not conditioning the body to run any faster, just further. And when they do a speed session in the week, their body is often still recovering from the high mileage so they aren’t able to run fast enough in training to make significant physiological changes to improve their long term speed.
By contrast, Mbition believes in a quality over quantity approach and our runner success figures back this up with 94.8% of our runners completing their goal. Our plans promote lower mileage than traditional running plans, focusing on high intensity sessions such as tempo, hill & speed workouts, that bolster the longer runs. The reason for this is because these sessions will simulate key physiological responses to improve your fitness and running conditioning. They also simulate the fatigue you’ll experience at the end of the race, but significantly reduce your risk of injury from the repetitive stress you place on your body from doing high-mileage runs.
There is no doubt that the ‘long’ run is the foundation to most running plans as it builds your aerobic fitness and muscular endurance, ensuring you can run the distance on race day. But weekly mileage shouldn’t be the main focus of your plan, because improving your running fitness comes from a combination of training volume and intensity. Plus high intensity sessions such as speed and hill sessions will help to improve your stride power, running economy, leg strength and aerobic endurance!