How many days per week should I do cardio in-season for hockey?

Cardiovascular training in-season is based on how many hockey games you are playing during the week.  The general rule is that you should perform two high-intensity cardiovascular days per week. If you are playing approximately eighteen minutes or more a game, this game day is considered a high-intensity training day for you. If you have two games per week and you are playing a lot, you should not need any additional interval training during the week.  The most important cardio days for a player who is often in the game are the recovery days after a game, training at a low intensity on either a bike, elliptical, or in the pool.  If you are not playing a lot of minutes in the game you will need to do some additional high-intensity intervals several times a week for ten to fifteen minutes to maintain cardiovascular strength.  Your anaerobic threshold and endurance training should be maintained by your normal practice schedule.