1. Increase your fuel to cover your training
Every day, you need to cover for what you run. This is not just during the run (though that is important too), but at meals and snacks outside of your runs as well. Many runners do not eat enough to cover for their training, which makes it hard for the body to recover and prepare for the next run. This can lead to injuries or illness during training. A rule of thumb is that you burn about 100 kcal per mile you run. Add this number to a base of 1500-1800 kcal daily for metabolic functions and daily activities outside of running. This is the total you should be eating each day.