What is a Tempo Run?
The tempo run is a workout designed to improve your lactate threshold, the point at which the body switches from its aerobic pathways into its anaerobic ones. However, the improvement of your threshold happens in a different manner than some of you are accustomed. In order to improve your threshold, you need to work above the threshold for an extended period of time and not below it (for example, if your threshold is 9:24 per mile, you would want to operate ideally at 9:25-9:30 pace per mile for the duration of the workout).
Therefore, it is possible to run too hard on a tempo run.
If you run too hard, you are stressing your aerobic capacity (which we do through the fartleks) and not your lactate threshold (also known in our terminology as anaerobic conditioning). To prevent this, the tempo will require some thought and patience. The tempo run will start around 20 minutes, we will add to it as you progress. The key indicator of a successful tempo run would be the progression of splits. A workout of 9:30, 9:26, 9:23, 9:18, would be far more preferable and beneficial than a progression of 9:18, 9:23, 9:26, 9:38.
It may take some time to find your starting point, just be intelligent, patient, and harness your aggressiveness early on. It is important to learn to stress the appropriate system for the workout detailed.
Where do I do a tempo run?
You want to avoid excessively hill terrain for a tempo run as that makes it more difficult to constantly be running the same effort (not pace, effort). Also someplace where you can get reliable mile splits is great. Additionally a tempo run is a continuous efforts, there is no stopping, with this is mind a location should be choose so that there are no stoplights or other areas which might cause a break in the effort. A track fits these criteria but can be boring, personally I prefer greenways that have mile marks as they are less repetitive, although I do utilize the track for tempos on occasion. Additionally if you have a GPS watch that opens up more options as long it is reliable.
How do I know if I’m going the right speed?
As with most workouts this one is based on effort. 80%-85% is about the range for a tempo run. One way to gauge is, could you run 5-10 seconds faster for another 5 min, but not much more than that? Then you’re probably going the right pace. This is not a workout where you’re falling down on the track in exhaustion afterwards, but it is a workout and you will be tired.
I don’t think I did it right.
That’s ok. You’ll have plenty of opportunities to practice tempo runs. The idea is to figure out what went wrong and to try to avoid it in the future. The biggest thing to work on is the negative progression of splits (each mile is equal to or faster than the one before). After that is keeping the mile splits within a somewhat narrow (10-15 second) range while accounting for terrain changes (uphill miles will be slower, etc.).