Hello! Remember last Wednesday when I talked about using fartlek work to increase your running speed (find that post here)? In that post I had mentioned that there are a lot of different types of speed work, and today I want to focus on a different one called tempo runs.


A tempo run, also called a lactate-threshold (LT) run, is a faster paced run that should be in the “comfortably hard” range. According to Runners World, “During tempo runs, lactate and hydrogen ions—by-products of metabolism—are released into the muscles. The ions make the muscles acidic, eventually leading to fatigue. The better trained you become, the higher you push your “threshold,” meaning your muscles become better at using these by-products. The result is less-acidic muscles (that is, muscles that haven’t reached their new “threshold”), so they keep on contracting, letting you run farther and faster.” (source) This is why we do tempo runs! To train our muscles to go farther and faster! Who doesn’t want to do that, right?

So what does “comfortably hard” mean for you?
There are a few different ways that can help you determine if you are running at a good tempo run pace.

1. Add 30-40 seconds to your 5K race pace or 15-20 seconds to your 10K race pace
2. If you monitor your heart rate, you want to be between 85-90% of your maximum heart rate
3. On on 1-10 point scale where 5 is your comfortable pace, you should be around an 8.
4. You should not be able to hold a conversation during a tempo run but you should be able to ask or answer a short question like, “good pace?”

How long do I run to get the benefits of a tempo run?
Tempo runs are generally shorter runs, but keep in mind that you need to be running long enough that your muscles can effectively adapt to using these by-products that are being released. How long you run will depend on your fitness level, but according to Runners World, the general recommendations are as follows:

  • If you are around the 5K range or for general fitness levels, your tempo run should be about 20 minutes long (this is after a warm up), or 2-3 miles
  • For a 10K range, you want a tempo run of 4-6 miles
  • A half marathon runner would want  a tempo run of 6-8 miles
  • For a marathon runner, your tempo run would be 8-10 miles

Who’s ready to get out there and do some speed work?!