Let’s say you are running on a treadmill and someone is viewing you from the side – you should NOT be leaning forward more than 1º or 2º. But when runners get tired, the vast majority of them lean forward at the hip. This is bad because they are now striking the ground too far in front of their center, causing a braking force with each stride. Not good.
The correction its cue are simple. The correction is to “run up tall.” Just say that in your head when you get tired – “run up tall.” You’ll likely revert to a 1º-2º forward lean, which is ideal as you want to strike just a touch in front of your center of mass, pushing back into the ground to propel yourself forward. Such a simple concept, such a simple cue – “run up tall” – but it will make a great difference in your pace in the final miles of a workout, a threshold run, a long run or a race.
The one thing to add here is that you need to strengthen your core – which includes the lower back and glueteal muscles, not just the abdominals – to be able to run with good running posture. So when you hear people blab on and on about core strength, they do have a point. If you do the GSM I prescribe, you’ll get this work in – work that I often think of as postural work. Run with good posture and you’ll run faster.