Outside the world of running, the word tempo is usually associated with music. It’s the speed at which a piece of music is meant to be played. Before metronomes, Italian composers would indicate the speed with words like: largo (slow, 40-60 bpm), andante (at a walking pace, 76-108 ), allegro (heartbeat tempo, 120-168 bpm), and presto (very fast, 168-200bpm). The tempo was meant to be sustained for the entire piece of music, unless otherwise noted.

In running, a tempo run is a run that is sustained at a specific pace for a specific amount of time. There are many types and variations of tempo runs but my preferred definition is a run that lasts for 20-30 minutes at a comfortably hard pace (RPE 7-8) or a pace that you can sustain for 1 hour. This is the magic threshold pace where your body switches from aerobic to anaerobic systems to convert glucose (fuel) into energy.

Why should you do tempo runs?

Tempo runs are done to increase your lactate threshold. By increasing our lactate threshold, we are able to run longer at a faster pace.

Lactate threshold is defined as the intensity of exercise at which lactate begins to accumulate in the blood at a faster rate than it can be removed. This is problematic because as a result, unbuffered acid is added to the blood, a condition that makes you feel like you have to vomit and stop right away.

Dr. Alexander Hutchinson, Active.com

Imagine that your body is a bucket. As you exercise, lactate accumulates inside the bucket but there are holes in the bucket that clears out the lactate. When you are exercising in your aerobic zone, the lactate is cleared out and doesn’t accumulate in the bucket. But when you run above your lactate threshold (i.e. in your anaerobic zone), the lactate accumulates faster than it can be cleared out. When you work to increase your lactate threshold, you are working to make the holes of the bucket bigger so you are able to clear out more lactate before reaching your lactate threshold so you can run longer at a faster pace.

Can tempo runs be too fast or too slow?

Yes and yes! When you are running faster than your tempo pace (RPE 8-10), you are no longer at your lactate threshold and it becomes an anaerobic workout. When you are running slower than your tempo pace, it becomes a run in your grey zone (RPE 5-6) which is not fast enough to have a benefit AND not slow enough to be a true aerobic workout.

Variations of tempo runs

• The classic tempo run is a run that lasts for 20-30 minutes at a comfortably hard pace (RPE 7-8) or a pace that you can sustain for 1 hour.
• Cruise intervals are intervals of 3-8 minutes done at a pace you can sustain for ~45 minutes
• Progression tempos are 20-40 min runs where you start the run at a pace where you can sustain for 2 hours (RPE 6-7) and progressively speed up your pace until you hit your target tempo pace (RPE 7-8).
• Long tempos lasts for 35-60 minutes at a pace you can hold for 75-120 minutes (RPE 6-7)
• Race pace tempos are sustained at your goal half marathon race pace or marathon race pace and is a good way to practice running at your goal pace before a race.

If you want to improve your pace, build in a tempo run once every week or every other week as a workout run. They should be less than 20% of your overall mileage. Remember to warm up, cool down, and schedule a rest day or easy day before and after a hard workout.

Happy tempo running!