There are many cross-training options available, but not all of them are of equal value to runners.
High volume doesn't always have to mean high mileage.
Give these alternate forms of exercise a try when running outside is not an option.
Should you be a maximalist, supplemental, seasonal, or emergency cross-trainer?
These three great cross-training alternatives for the injured runner are also great conditioning supplements for the healthy runner.
Non-running forms of exercise has its benefits, too.