The best running plans include a mix of sessions designed to develop different aspects of your fitness. Each workout varies in volume and intensity – some involve intervals of harder efforts with static or walking recoveries (threshold intervals), while others focus on longer, continuous runs with short jog recoveries between efforts (tempo runs).
By including a variety of sessions in your training, you teach your body to run efficiently at different speeds and intensities. This balance helps you build endurance, speed, and strength, all key to improving your overall running performance.
The Science Behind Thresholds
'Threshold' is a scientific term that refers to your ability to tolerate the build up of lactate during exercise. When you run, your body produces lactic acid, and it tries to clear this out whilst you're on the move. A build-up of lactic acid causes discomfort and fatigue and will eventually slow your run down.
If you're well trained, your body is able to create and clear out the lactate at the same rate whilst you're running. During these runs, you will not reach your lactate threshold. However, if you up the pace and start to run faster, you will get closer to this threshold and eventually above it.
In a nutshell, the faster you run, the closer or more likely you are to hit your lactate threshold. Thresholds are individual; it's specific to you and your current level of fitness.
Ultimately, if you can improve your lactate threshold you will be able to run faster for longer. You do this by running threshold interval and tempo sessions.
How to Calculate Your Lactate Threshold and Threshold Pace
The most accurate way to calculate your threshold is by doing a laboratory test, however this is not a convenient or practical option for most people. Other options include:
Heart rate: Your running threshold is around 80-90% of your maximum heart rate, also known as Zone 4 (threshold zone). By using heart rate, you can track how your threshold pace changes as you get fitter. You can learn more about heart rate in the article below.
Threshold Time Trial (30-60 minutes): Your threshold pace is the fastest pace you can sustain without fatiguing – roughly what you could hold for about an hour.
If you’re an experienced runner, try a 60-minute time trial for the most accurate result.
If you’re newer to running, or want a simpler option, do a 30-minute test instead – run at a pace that feels challenging but sustainable for the duration and take your average pace from the final 20 minutes as your threshold pace.
Both methods will give you a strong benchmark to guide your training, the key is finding a challenging pace that you can hold without completely fading.
If possible, use a local race that lasts roughly the same amount of time as your threshold test, or you could use your results from a recent race.
Go on feel: Threshold effort is one that feels comfortably hard but that you can sustain for up to an hour. It won't leave you gasping for breath, like a 5k race or a sprint.
Threshold Intervals vs Tempo Runs: What's the difference?
So, let's now see how threshold and tempo runs compare, and what each one involves.
Threshold runs (a.k.a. interval sessions)
Threshold training involves training at or just under your current threshold level. This helps train your body to become more efficient at clearing lactate.
Threshold sessions will usually include shorter intervals with periods of recovery. This allows us to run at a harder effort (faster pace) with short breaks to help stop the build up of lactate.
Your Runna plan guides you though your interval sessions with personalised pace targets based on your fitness levels and race results.
Check out this episode of Runna TV, where coach Kayla guides Aisha through an interval workout and explains how they benefit your performance!
Tempo runs
Your tempo pace is close to your threshold pace, and this is where the confusion between tempo and threshold/intervals arises. Your tempo pace is the more sustainable pace that we mentioned above. It targets your aerobic base, therefore helping you improve your endurance. Tempo sessions involve longer reps, without complete rest periods.
This is more common if you are training for a longer distance (half marathon and above), but tempo runs still have an important role to play for all distances.
Threshold (interval) vs tempo runs in your Runna plan
To keep things clear, we've included two types of sessions in your Runna plan:
Intervals, with short bouts of effort above your lactate threshold; we could call these threshold runs.
Tempo runs, at your actual threshold pace, which you can sustain for longer.
Here's how the two compare:
Intervals
During these sessions you will spend time above your 'sustainable' pace (i.e. your lactate threshold). It forces your body to adapt and become more comfortable running at these higher speeds.
Tempo runs
During these sessions you will spend longer periods of time running at a more sustainable but still challenging pace. These workouts are key to condition the body to become faster over longer distances.
The effort will typically be between half marathon and 10k pace, but like any run, your pace might vary day to day! Your pace will also vary depending on the length of the rep.
The key note is keeping it to 70-80% effort. If you go too quick, you will be closer to your lactate threshold (save that for your intervals!).
Get a tailored training plan to become a better runner
With Runna, you can follow a personalized training plan tailored to your goals, fitness level, and schedule. Each week includes a mix of interval sessions, tempo runs, long runs, and easy runs, all designed to guide you with clear pace targets and easy-to-follow workouts.
By training at a variety of paces and distances, you’ll build endurance, strength, and speed, helping you become a stronger, faster, and more confident runner over time.