What Is a Tempo Run? The Science-Based Guide to Threshold Training

Many runners misunderstand tempo runs. Lactate threshold (LT) training is one of the most powerful tools for improving race performance — yet knowing how to incorporate it effectively remains a challenge for many.

From my own experience, adding structured tempo runs to my training led to a dramatic improvement in my race times.

Tempo runs go by many names: “LT runs,” “threshold runs,” and “pace runs.” The terminology varies by coach and runner, though tempo run and threshold run are used interchangeably in most contexts.

This article breaks down everything you need to know about tempo runs — what lactate threshold means, how to structure your sessions, and how to maximize the benefits of this essential workout.

By the end, you’ll be able to set the right tempo run pace for your current fitness level — and start making real progress toward your race goals.

Tempo runs are simple in structure but highly effective. Elite marathoners and everyday runners alike rely on them as a cornerstone of their training.

What Is a Tempo Run? (Definition)

In this article, I define a tempo run as follows — consistent with Jack Daniels’ Running Formula:

Tempo runs are also called “threshold runs,” “LT runs,” and sometimes “pace runs.” While usage varies, tempo run and threshold run are typically treated as synonymous, while “pace run” tends to refer to a slightly slower variation of the same concept.

In Daniels’ Running Formula, the pace for a tempo run is called “T-pace.” T-pace is defined as “the pace you can sustain for at least 20–30 minutes in a workout.”

When fully rested and tapered, most trained runners can hold T-pace for about 60 minutes.

After finishing a tempo run, if you’re doubled over with your hands on your knees, you’ve pushed a little too hard. The right effort level is one where you finish thinking, “I could probably run one more kilometer.”

Sustaining T-pace is genuinely uncomfortable. Personally, I feel a slight sense of dread before every tempo session — and that’s completely normal.

Benefits of Tempo Runs

Tempo runs target the following adaptations:

Tempo runs are unique in that they address both lactate threshold and VO2 max in a single session.

LT velocity — the speed at which you run at your lactate threshold — is a composite measure reflecting VO2 max, running economy, and lactate threshold itself. Research shows it is the single best physiological predictor of distance running performance ※1. In other words, raising your LT velocity directly translates to faster race times.

A common misconception is that tempo runs only benefit lactate threshold. In reality, because they are performed at 88–92% of max heart rate, they also provide a meaningful stimulus for VO2 max.

Additionally, because tempo pace closely matches half marathon and marathon race pace, regular tempo runs build race-specific running economy — your ability to run those paces more efficiently over time.

Tempo Run Workouts: Two Approaches

There are two main formats for tempo run workouts: the continuous “tempo run” and the broken-up “cruise interval” approach.

Both formats use the same target pace. Cruise intervals feel easier because the effort is distributed across segments, which also allows you to accumulate more total volume at threshold pace compared to a continuous run.

Continuous Tempo Run

The most classic form of threshold training: run at T-pace continuously for 20–30 minutes. It’s the hardest format mentally and physically — but it builds your ability to sustain a comfortably hard pace under race-like pressure.

The benefit of continuous tempo runs is that they train you to hold a challenging pace without breaking it up. As races require sustained effort over time, developing that tolerance in training pays off on race day.

As your goal race approaches, continuous tempo runs become especially valuable for building race-specific fitness and sharpening your sense of effort at goal pace.

When running solo, a practical target for T-pace is your current half marathon race pace.

Cruise Intervals

Cruise intervals split the tempo run into shorter segments with brief recovery jogs in between. Recovery time is typically about 20% of the rep duration.

Recovery is done at jogging pace, not full rest. The blood lactate that builds up during the hard effort is metabolized during low-intensity aerobic movement. Recovery is an active and essential part of the workout, not downtime.

The advantage of cruise intervals is that the distributed effort makes the workout more approachable, and you can accumulate more total threshold volume than in a single continuous run — with nearly the same training effect.

Keep the pace the same for cruise intervals as for your continuous tempo runs. Pushing faster shifts the workout’s purpose — and that defeats the point.

Running Slower Than T-Pace: Steady-State Runs and Sweet Spot Training

Many runners also train at paces slightly below T-pace — faster than easy pace but not quite at threshold. In this article, I refer to this as a “steady-state run”: sustained running at a pace between easy pace and T-pace.

Can You Still Improve Your Lactate Threshold?

The short answer is yes — running below T-pace can still improve your lactate threshold. However, there is a meaningful difference between a true tempo run at T-pace and a steady-state run at a slower pace.

That difference is the stimulus for VO2 max.

Helgerud et al. (2007) ※2 compared four training intensities (70%, 85%, and 90–95% of max heart rate). Interval training at 90%+ max heart rate improved VO2 max by up to 13% and significantly increased cardiac output. Lower intensities produced smaller VO2 max gains.

This suggests that true tempo runs at 88–92% max heart rate provide a meaningful VO2 max stimulus, while steady-state runs at slower paces may have little to no effect on VO2 max.

If your goal is purely to improve lactate threshold, slower steady-state runs can work. But for the full combination of benefits — LT improvement plus VO2 max stimulus — running at T-pace is worth the extra effort.

Pace Reference Table (Downloadable)

How long do you need to run at a slower pace to get the same training load as a 20-minute tempo run at T-pace? I’ve put together a threshold pace table to answer exactly that.

The table shows how many minutes you need to run at paces ranging from T-pace down to marathon pace to achieve an equivalent training stimulus. The key column to look at is T-pace.

As an example, take a runner with a half marathon time of 1:14:40. Their T-pace is 5:41/mile. Running 5:41/mile for 20 minutes is a standard tempo run at T-pace.

If that same runner drops to 5:52/mile, they would need to run for 40 minutes to accumulate the same training load — according to the table.

Sweet Spot Training (SST)

Running at a pace slower than T-pace is sometimes called Sweet Spot Training (SST) — a term well known in cycling that is gradually gaining traction among runners.

The “sweet spot” refers to a blood lactate range of approximately 2.0–4.0 mmol/L, which roughly corresponds to marathon pace. It’s an intensity that lets you accumulate significant training volume without excessive fatigue — making it an efficient tool when used strategically.

How to Set Your Tempo Run Pace

Tempo runs should be performed at a pace you can sustain for 20–30 minutes in a workout. As discussed above, this generally corresponds to your current half marathon race pace — not your goal pace, but the pace you can run right now.

Method 1: Use the VDOT Calculator

The most reliable way to find your T-pace is through your VO2 max (VDOT), which you can estimate from a recent race result. Jack Daniels’ VDOT Running Calculator does this automatically.

Use a recent race result — not a goal time or a personal record from years ago. Your T-pace should reflect where your fitness is today, not where you want it to be.

Method 2: Use Heart Rate or Perceived Effort

If chasing a specific pace feels too stressful mentally, training by heart rate or perceived effort is a solid alternative.

According to Daniels’ Running Formula, the target intensity for tempo runs — T-pace — differs depending on training experience:

These heart rate targets refer to your heart rate in the latter portion of the tempo run, not at the start. Heart rate will be lower at the beginning and rise as the effort continues.

If you plan to use heart rate for pacing, a wrist-based optical heart rate monitor is not ideal. Accuracy limitations make it unreliable for structured training.

For reliable heart rate monitoring, use a chest strap heart rate monitor or an armband optical monitor. Armbands use the same optical technology as smartwatches but with a better fit and measurement position, resulting in improved accuracy.

For recommendations and a buying guide, check the article below. I personally use a COROS armband heart rate monitor.

Real-World Results: How Tempo Runs Boosted My Half Marathon Time

Here’s a personal example of how tempo runs made a difference.

The moment I truly understood the power of tempo training was when my half marathon time improved dramatically after I started incorporating structured tempo runs.

I charted both my half marathon times and my tempo run training paces over time. The workout I used was the simplest version: a 20-minute continuous tempo run.

In the graph, the x-axis shows the tempo run training pace, and the y-axis shows half marathon race time. Every data point falls nearly on a straight line — a clear illustration that tempo run pace directly predicts half marathon performance.

Tempo runs at lactate threshold pace are highly specific to the half marathon — and the data shows it.

Over time, I was also able to predict my race time from my training pace. Knowing how fast I’d run on race day — before the race — became possible through consistent tempo work.

Key Tips for Effective Tempo Training

Tempo runs improve lactate clearance, raise your LT velocity, and can even stimulate VO2 max gains. They’re also highly race-specific — making them one of the most versatile training tools for distance runners.

Here are two things I consider essential to getting the most out of tempo training.

Consistency and Intensity Control

The first key is training consistency and intensity control.

Like all endurance training, the benefits of tempo runs come from repeated sessions over time. Lactate threshold improvements in particular take time to develop — there are no shortcuts.

If the workout is too hard to sustain week after week, you won’t get the adaptation you’re after.

In that case, consider controlling intensity by heart rate or perceived effort rather than by pace. How hard a given pace feels varies day to day depending on fatigue, sleep, and conditions.

Managing by feel or heart rate increases the odds that you’re actually training at the right intensity on any given day — and reduces the chance of failed sessions (missing the pace or cutting the workout short).

Training Reproducibility: The Secret to Race-Day Performance

Training reproducibility means being able to complete the same workout — same route, same duration — at the same pace and perceived effort, session after session.

On race day, you run with whatever conditions you’re given. In training, you can control much more: the time of day, nutrition, course. Standardizing these variables as much as possible makes each tempo session more comparable and meaningful.

When you run tempo sessions with high reproducibility, you’ll eventually notice that the same pace starts to feel easier. That’s how you track both your daily form and your long-term fitness gains.

And over time, this translates directly to race performance. When the same pace feels easier in training, you can gradually raise your target pace — and your race times will follow.

References

※1 Bassett DR Jr, Howley ET (2000) “Limiting factors for maximum oxygen uptake and determinants of endurance performance” Medicine & Science in Sports & Exercise

※2 Helgerud J, Hoydal K, Wang E et al. (2007) “Aerobic high-intensity intervals improve VO2max more than moderate training” Medicine & Science in Sports & Exercise