These simple suggestions to safely start inserting some speed work into your training schedule.
Strides: Strides are an easy and effective way to gently fire up those fast-twitch muscle fibers that will power your future speed workouts. So, how do you do them? In the beginning, a set of four to six strides two to three times a week after your regular runs is plenty. As your training progresses, strides will become something of a speed maintenance session, as well as serve as part of a warm-up routine for some of the more advanced speed workouts described in the following pages.
Fartlek: Fartlek is a series of faster pickups with a recovery interval in between. A mix of short, fast running and longer, steady stretches will tap into your anaerobic system and increase your aerobic capacity, thus improving your ability to maintain a faster pace. Perform a fartlek workout once a week and allow yourself a few days of easy running or rest afterward to ensure you recover completely.
Track Workouts: Introduce track workouts into your training schedule only after strides have become part of your regular routine and you've had some fun with a few fartlek workouts. When setting out to do a track workout, warm up with a mile or two of easy jogging and then perform a set of four to six strides in order to get your fast-twitch muscle fibers ready to do some work. Track workouts are very demanding on the body, so performing them once a week is plenty, especially if you're racing regularly.