mental wellbeing can be a major factor. I was in the meat of my marathon training and banging out 12-14 mile runs no problem, had an argument with the missus seconds before leaving for a run and was so angry it completely threw my mojo off and I barely made it 2.5 miles before packing it in and walking back home. just felt like i physically couldn't move faster than a walk.
mental wellbeing can be a major factor. I was in the meat of my marathon training and banging out 12-14 mile runs no problem, had an argument with the missus seconds before leaving for a run and was so angry it completely threw my mojo off and I barely made it 2.5 miles before packing it in and walking back home. just felt like i physically couldn't move faster than a walk.