Fartlek Training is a great way to push your limits of speed and endurance in running. Fartlek is a Swedish word meaning “speed play,” (Dictionary.com) and is incredibly simple to incorporate into your running routines.
The basic strategy for Fartlek style training is short durations of higher intensity running followed by longer durations of lower intensities. For example, a Fartlek run could consist of 30 minutes of alternating between 30 seconds of running at a pace of about 85-90% of your all-out sprint pace followed immediately by a minute of running at about a 40-50% pace with no rest in between.