I currently play futsal and also indoor, but will be trying out for my University's team in about a year's time. Obviously, outdoor requires much more running and I would like to increase my endurance.
I have no problems finishing games on the smaller fields that I play on now, but while talking to some of my friends that have played for professional teams as well as some of the better UC (Cali) teams I've realized I can be expected to run 5-9 miles per game depending on my position.
I currently run ~4 miles around 3-4 times a week (less or more depending on how I feel) and would like to be able to run around 8 miles at a time.
I'm wondering how I would progress to get up to around 8? Should I add a quarter mile every month? Every 2 weeks or so?