Everything You Need to Know About Threshold Runs

Are you looking to improve your times at marathons, half-marathons or any other long distance race? Then it’s definitely worth building some threshold runs into your training plan. Threshold running is a powerful technique for improving your endurance, speed and stamina. It’s not the easiest form of training, but can have serious benefits.

You may well have heard about threshold running from other runners, people at your running club, or in running magazines. But what exactly is a running threshold, and what does threshold running involve?

What is a running threshold?

When you do physical exercise your body produces lactate. This is the byproduct of your body breaking down carbohydrates to produce energy in anaerobic exercise. Most people can naturally clear lactate while doing slow and steady exercise. But if you exercise at higher intensity, you cross the lactate threshold, which is the point at which the concentration of lactate increases dramatically. A byproduct of this process is positively charged hydrogen ions, which is acidic and causes the sensation of ‘burning’ in our muscles.

For a full rundown of how this works at the physiological level, read our article on increasing your lactate threshold.

However, if you run at just below your lactate threshold, you should be able to maintain a reasonably fast pace, without having to slow down. And the good news is that your body will adapt if you regularly run at just below your lactate clearance threshold. Essentially, your body gets faster at processing lactate, so you can run at higher speeds for longer.

A note on lactic acid and lactate

Many people use the words ‘lactic acid’ and ‘lactate’ interchangeably. However, they are different chemicals, the human doesn’t actually produce lactic acid. Lactate is in fact highly beneficial to our performance during intensive activity. As noted above, the thing that makes your muscles ‘burn’ during exercise is hydrogen.

What is a threshold run?

A threshold run is when you run at just below your lactate threshold. This kind of running is often described as ‘comfortably hard’. You don’t want to be running so fast that lactate builds up and brings you to a grinding halt. But you do want to be running close to that level.

What does threshold running look like?

Say your running threshold was 10 minutes per mile - if you ran any faster than this, you’d soon have to stop.

For a threshold run, you might start with an adequate warm up (in order to prevent injuries). Then, you would aim to run at around 10:30 per mile for four miles, before dropping back to a slower pace for the final two miles. By running just below your threshold, you’re making your body work to clear lactate. By doing this kind of training regularly you’ll notice you can run at just below your threshold for longer.

What is a threshold runner?

A threshold runner is quite simply anyone who actively does threshold running. Everybody’s threshold is unique to them - an experienced runner will typically have a much higher threshold than someone who’s just started out. But anybody can start threshold running and begin to see the benefits.

Threshold runners often train on tracks (or sometimes treadmills) because they offer a smooth, consistent surface where there won’t be any obstacles slowing you down (such as traffic lights, pedestrians or roadworks). Using a track or treadmill also gives you a really easy way to calculate speed, distance and time, since you know the track is a specific length.

What is the purpose of threshold running?

Threshold runs are essentially intended to increase the speed at which your body clears lactate from your bloodstream. This means you can run at higher speeds for longer. That can help you achieve faster race times and they should definitely be part of any marathon training plan.

Threshold running is regarded as one of the most effective ways of improving your running efficiency. Research suggests that efficient lactate clearance has a larger impact on performance than factors like VO2 Max, running economy, or even age. So, it’s definitely worth focusing on threshold running if you want to beat your PB.

How to calculate your running threshold

If you want to start running at your threshold, you first need to know how to calculate what your threshold actually is. So, let’s look at how you can calculate your own personal running threshold.

There are several ways you can figure out what your threshold running pace is. Some are technical and highly accurate, others are simpler, but still effective:

• Get your lactate threshold scientifically studied: If you want to know your precise running threshold, you can visit a sports science laboratory where you will run on a treadmill and have your blood tested. This data will give you the most accurate information on your lactate threshold. However, it's an expensive process that's only really necessary for professional runners.
• Use a running watch: Generally speaking, your body will reach its running threshold when it is at about 85-90% of maximum heart rate. Certain kinds of running watches are able to monitor your heart rate and give you a good idea of what your threshold is.
• Calculate against your race time: Threshold running pace is often considered to be just a little faster than your average pace at a half marathon. If you have experience of doing several races, you can use your running time to figure out your mile or kilometre speed. A threshold run is simply a little bit faster than your race speed. If, for example, you run a mile at half marathon pace in 10 minutes, your threshold running pace would be around 9:45.
• How it feels: For many runners - especially those with a bit more experience - the way they feel can be a good gauge of when they’re running at their threshold. A threshold run is simply one that feels comfortably hard - you should not be completely out of breath as if you were taking part in a 5K race, but it should certainly be tougher than a casual jog. The point is that you should be able to continue running several miles at this speed without needing to stop.

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Benefits of threshold runs

Building threshold running into your training plan provides multiple benefits. These include:

• Boosting your overall endurance
• Allowing you to run faster for longer
• Making your body more efficient at clearing lactate
• Increasing your maximum heart rate
• Increase your VO2 max
• Helping you to cut fatigue
• Improving your marathon time
• Helping your body use fast twitch muscle fibres more effectively

Other tips for threshold running

Running at your threshold is meant to be challenging, and can soon get very tiring. Here are some tips to make running threshold easier:

• Listen to music: Choosing a playlist of songs at a higher beat per minute can get you into the mood for running at pace.
• Run with a friend: Running with other people can get you into a rhythm and motivate you to go further.
• Run on track or treadmill: Running on a track or a treadmill for tempo runs and threshold runs allows you to very accurately monitor your speed and distance.
• Avoid running in adverse conditions: Doing tempo or threshold running in wind and rain makes doing these exercises harder. It is preferable to do them during calm weather.
• Try other exercises: Check out our guides to other running training methods such as Fartlek training or interval training.

If you are building up to a marathon or another long-distance race, choosing to do threshold runs will certainly help to improve your overall time, speed and endurance. And with the right running gear and training plan, you should start to see an improvement in no time.

Go further and faster with threshold running

If you are building up to a marathon or another long-distance race, choosing to do threshold runs will certainly help to improve your overall time, speed and endurance. And with the right running gear and training plan, you should start to see an improvement in no time.