Fartlek and tempo runs both involve speed work, but they are structured very differently.
Fartlek is a Swedish word for “speed play” and I love to use it just for that—play! Fartlek involves pick-ups of a faster pace throughout a run and can vary in duration and intensity. So while you are out for an easy paced run, pick up the pace to a moderate-fast speed until a tree/street sign/food cart/etc. Then return to your easy pace until the next challenge.
These runs help build your fatigue resistance and running efficiency, and can help break up an intense training plan. This is also a great opportunity to run without a watch or device and really listen to how your body is feeling at the different intensity levels.
Tempo runs are just the opposite, with a structured program of warm-up, tempo miles, and then a cool-down. Tempo runs begin with a warm-up at an easy pace, followed by a set number of miles of a sustained effort at your threshold. Typically these miles are similar to a 10K pace—you shouldn’t be able to hold a conversation, but you shouldn’t be fighting for air, either. Your tempo miles should all be completed at the same pace, so if you feel like you have to slow down throughout, be sure to reassess your effort level.
It is important to follow the tempo miles with one to two miles at a cool-down pace in order to allow your body a gradual return to resting levels. Tempo runs are just outside of our comfort zone, and they help increase our lactate threshold and improve our running economy at a faster pace. Tempo runs are great for getting comfortable with being uncomfortable, which is a key factor for race-day success.
Pamela Geisel, MS, CSCS, CPT is an Exercise Physiologist at Hospital for Special Surgery’s James M. Benson Sports Rehabilitation Center and Tisch Sports Performance Center. She graduated with honors from Towson University with a bachelor’s in exercise science and received her master’s in exercise physiology from Adelphi University. She has been in the fitness field since 2007 and has a special interest in using strength training to maximize performance and reduce injury for runners. Geisel is a long-distance runner and has completed seven marathons, more than a dozen half-marathons, and many 5K and 10K races.