The Fartlek method is an age old running method that has been helping athletes progress for the past 50 years. Fartlek is a Swedish term for "speed play", and is a training method consisting of a series of sprints within your normal length run. These sprints are short bursts, usually 30 seconds in duration that occur as little as five times within a beginner?s 45 minute workout.
First, focus on a stationary object in the distance, like a tree or telephone pole, and then increasing your pace to somewhere about 70% to 90% of your maximum speed until you reach that landmark. At this point, you should return to your original pace as your heart rate and lactic acid levels restore themselves and recover for the next sprint. After about 5 to 8 minutes, you should be ready to begin your second burst. Once you begin to become stronger and fit, you can add up to an additional 5 sprint intervals to your workout.
This technique has proven to be very useful for a wide variety of strength and endurance athletes. By listening to your body, you decide how far, how fast and how long you will increase your intensity all the while continuing within the parameters of your normal workout routine.