A key piece of running advice, especially for the beginning runner, is, counter-intuitively, to not run so hard. In order to build endurance and be able to run for long periods of time, we are taught to back off the pace. Ideally, you should be able to carry on a conversation while you run. If you’re breathing too hard to speak in full sentences, you are running to fast.
That’s all well and good as a starting point, but eventually most of us start dreaming of new PRs and ways to train better. And in order to run faster, you do, at some point, need to work on running faster.
If you’re at the point of upping your running game, threshold running is a key workout type. This is especially true for distance runners because it helps you avoid over-training while still getting in plenty of hard effort.
In this article, we’ll cover what threshold pace is, how to determine it, and how to use it in training. By the end, you’ll know how to best take advantage of threshold pace runs for optimum results.
What is Threshold Pace?
Depending on how long you’ve been a runner, you may or may not be familiar with the phrase “threshold pace,” also known as “T-pace.” Quite simply, it is short for lactate threshold. This is the intensity of exercise where there is a rapid increase in blood lactate levels.
Lactate is not inherently bad. But run hard enough for long enough, and your body’s lactate production will exceed its ability to process it out of the bloodstream. The result is a rapid buildup of lactate. Which hurts.
The tipping point, where your body can no longer keep up with the lactate it is producing, is your lactate threshold. The corresponding pace is your threshold pace. The idea of threshold training is to train just below that threshold pace, to build up your body’s ability to deal with lactate. It is threshold runs that develop your ability to push harder for longer periods of time.
Why You Should Train at Threshold Pace
You should train at threshold pace because it will help you improve your strength and endurance gradually. It’s especially key for distance runners so that they can get faster even as the distance increases.
In essence, you’ll be able to run faster and longer the more you train at threshold pace. Training at threshold pace improves your body’s ability to deal with lactate, delaying fatigue, meaning you can run faster and harder.
How to Determine Threshold Pace
Broadly, threshold pace is a little bit faster than your half marathon race pace. So, if you run a 9-minute-mile for a half marathon, threshold pace will be about 8:45 or 8:30.
If you want to figure out based on the feel, you can try the talk test. Can you say three or four-word sentences (but not any longer)? Or try the exertion test. How hard do you think that you’re running? If it’s close to an 8 out of 10 in terms of difficulty, you’re probably close to threshold pace.
But a better way to figure out your threshold pace is to use the time from a recent race and use an online running calculator to figure out your exact threshold pace. If you’ve been running for any length of time, you may even have an idea of what your threshold pace is.
Even more precisely, the proper threshold pace is about 83 to 88 percent of your VO2 Max. Many coaches refer to threshold pace as “comfortably hard.” It’s a pace that you can keep for 50-60 minutes, no matter how far you can go.
If you prefer heart rate, threshold pace is about 75 to 80 percent max heart rate. If you want to be more scientific about it, you can even figure out what this would be for you and monitor your heart rate during your run with a smartwatch.
A way that you can figure out your lactate threshold if you want to use heart rate is to run on a treadmill for 30 minutes after a brief warm-up. Make sure that your effort is sustained. Check your heart rate at 10 minutes and then at 30 minutes and divide by two. That’s your lactate threshold heart rate.
Studies have found this to be quite effective in figuring out your threshold pace, but it does require some effort—running hard for 30 minutes, but at a pace you can sustain.
I was guessing that my threshold pace would be somewhere around 8:30, and when I entered my information from a recent race, I was pretty close: 8:39 per mile. And as a side note, it correctly estimated my half marathon time within a minute.
Threshold pace is a key reference point for other training sessions, as well. The calculator suggested paces for easy runs, long runs, intervals, and repetitions. I now use these numbers to set training goals.
How to Incorporate Threshold Pace Into Your Training Runs
Depending on what type of run you’re completing, you will use the threshold pace information differently. Longer runs should be slightly below threshold, while short intervals should be above.
As a brief guide, you should run short intervals (0.25 and 0.5 miles) above threshold pace, other intervals at threshold pace, sustained runs at threshold pace, and longer tempo runs just below threshold pace.
This means that if you take my information, I should be running short intervals at an 8:00 pace or faster, sustained runs at 8:30, and longer tempo runs at 8:35-8:45.
You might consider trying to add one threshold pace workout in your training plan each week, and there are a couple of ways to do so.
You could try a progression run of 8-12 miles. You’ll start at 20-30 seconds slower than your threshold pace and gradually increase the pace until you’re at your threshold pace in the last 2 or 3 miles.
Or the ever-simple threshold miles or threshold run. For the former, run 4-6 individual miles with 90 seconds of rest in between. For me, this would be at least 4 miles at an 8:30 pace. Or run 3-4 miles continuously at your threshold pace.
How to Know that Threshold Training is Working
It’s important to keep in mind that a consistent and proper threshold pace is more important than a fast pace. You want to give your body consistency to train yourself to push harder for longer.
It’s ideal to use threshold training and tempo runs on relatively flat terrain because you’re trying to stay as consistent and steady as possible. Variations like hills will make it harder for you to maintain a steady threshold pace, even if you are measuring by effort or heart rate.
You need to make sure that you aren’t pushing yourself too hard. Ideally, you should complete a particular workout regularly during your training plan and see if it becomes easier over time.
For example, let’s say that you want to include a tempo run of 4 miles at threshold pace—mine is 8:30—in your training plan. Do that once a week for a month and see how you feel at the end of the month. There’s a good chance that it has gotten easier.
You of course can check your heart rate during your workout to see how everything is going. But make sure that isn’t distracting you from the main purpose of figuring out how you feel and keeping your pace steady.
In the end, using threshold pace for training is great because it gives you a benchmark. Plus, unlike the endurance runs that are typically earlier in a training program, you can use threshold training any time during your running program.