Tempo runs are the bread and butter of distance running training. They build the metabolic machinery that allows you to sustain faster paces for longer periods—the exact adaptation needed for racing anything from the 5K to the marathon. Done correctly, tempo workouts are the most effective way to raise your lactate threshold and improve race performance.
Yet many runners either avoid tempos because they seem intimidating, or they do them too hard and turn them into races. The key is finding that "comfortably hard" sweet spot—hard enough to stimulate adaptation, sustainable enough to complete quality work. This guide teaches you exactly how to find and execute that pace.
Key insight: Tempo pace should feel "comfortably hard"—you're working, but you could hold the pace for an hour in race conditions. If you finish a tempo run completely shattered, you went too fast.
The Science of Threshold Training
Your lactate threshold is the exercise intensity at which lactate begins to accumulate in your blood faster than your body can clear it. Below this threshold, lactate levels remain relatively stable; above it, they rise exponentially, leading to fatigue and eventual slowdown.
What Threshold Training Does
- Raises lactate threshold: You can sustain a faster pace before accumulating lactate
- Increases lactate clearance: Your body becomes better at processing lactate as fuel
- Improves running economy: You become more efficient at threshold pace
- Builds mental toughness: Teaches you to sustain "comfortably hard" effort
- Improves race pace: Threshold pace roughly equals 1-hour race pace
Threshold Intensity Markers
- Heart Rate: 85-90% of max HR (or 75-90% of HRR)
- Breathing: Heavy but controlled, can speak in short sentences
- Perceived Effort: 6-7 on a 1-10 scale ("comfortably hard")
- Sustainability: Could hold for ~60 minutes in race conditions
- Blood Lactate: ~4 mmol/L (if testing)
Finding Your Threshold Pace
Accurate threshold pace is crucial—too fast and you can't complete the workout; too slow and you don't get the training stimulus. Here are proven methods to find your pace.
Method 1: Race Time Calculation
Use a recent race to estimate threshold pace:
- From 5K time: Add 25-35 seconds per mile to your 5K pace
- From 10K time: Add 15-20 seconds per mile to your 10K pace
- From Half Marathon: Your half marathon pace is close to threshold pace
Example: 5K race pace of 7:30/mile → Threshold pace of ~7:55-8:05/mile
Method 2: Jack Daniels VDOT
The VDOT system uses race performances to calculate equivalent training paces. Enter a recent race time into a VDOT calculator to get your "T" (threshold) pace.
Method 3: The Talk Test
Run at a pace where you can speak in short sentences (3-5 words) but can't hold a comfortable conversation. If you can chat freely, you're too slow. If you can't talk at all, you're too fast.
Method 4: Heart Rate
Calculate threshold heart rate zone:
- Using Max HR: 85-90% of maximum heart rate
- Using Heart Rate Reserve (Karvonen): 75-90% of HRR + resting HR
- Using LTHR: If you've done an LTHR test, threshold is 95-100% of LTHR
Pace Will Vary by Conditions
Threshold pace slows in heat, humidity, altitude, wind, and on hills. Adjust by effort/heart rate rather than hitting an exact pace in challenging conditions. A hot day might mean running 10-20 seconds per mile slower at the same effort level.
The Classic Tempo Run
The traditional tempo run is a sustained block of running at threshold pace, sandwiched between a warm-up and cool-down. It's the foundational threshold workout.
Classic Tempo Structure
Warm-Up: 10-15 minutes easy
Gradually increase pace, include dynamic stretches and strides
Tempo Block: 20-40 minutes at threshold pace
Steady, controlled effort—resist going too fast early
Cool-Down: 10-15 minutes easy
Very easy jogging to begin recovery
Tempo Run Progression
| Experience Level | Tempo Duration | Frequency |
|---|---|---|
| Beginner | 15-20 minutes | 1x per 7-10 days |
| Intermediate | 20-30 minutes | 1x per week |
| Advanced | 30-45 minutes | 1-2x per week |
Cruise Intervals
Developed by legendary coach Jack Daniels, cruise intervals are repeat efforts at threshold pace with short recovery jogs. They allow you to accumulate more quality time at threshold pace than a continuous tempo run—especially useful for runners who struggle to maintain form during long tempo blocks.
Cruise Interval Structure
- Work interval: 5-15 minutes at threshold pace
- Recovery: 1 minute jog (very short!)
- Total work: 20-40 minutes
The short recovery keeps lactate slightly elevated, maintaining the training stimulus while allowing just enough recovery to maintain pace quality.
Sample Cruise Interval Workouts
Beginner
3 × 8 min T pace / 1 min jog
24 min total @ threshold
Intermediate
4 × 1 mile T pace / 1 min jog
~25-30 min total @ threshold
Advanced
5 × 1.5 mile T pace / 1 min jog
~40-45 min total @ threshold
Marathon Specific
3 × 2 mile T pace / 1 min jog
6 miles @ threshold
Tempo Workout Variations
Beyond classic tempos and cruise intervals, several variations keep training fresh and target specific race demands.
Tempo with Surges
Classic tempo with brief pickups to simulate racing moves. Teaches you to change gears without losing rhythm.
Example: 25 min tempo with 30-second surge every 5 min
Cut-Down Tempo
Start slightly slower than threshold and gradually increase pace. Teaches pacing discipline and negative splitting.
Example: 4 × 5 min, each 5-10 sec/mile faster than previous
Fartlek Tempo
Unstructured tempo with varied paces based on feel or terrain. Less mental pressure than exact pace work.
Example: 30 min of tempo-effort running with natural pace variations
Broken Tempo
Longer reps with slightly longer rest than cruise intervals. Good for building toward continuous tempo runs.
Example: 2 × 15 min @ T pace with 3 min easy jog
Progression Runs
Progression runs start easy and gradually build to tempo effort (or beyond). They teach your body to run fast when tired and practice negative splitting. They're less stressful than tempo runs because only part of the run is hard.
Progression Run Structures
Easy-to-Tempo Progression
Start at easy pace, finish last 15-20% at tempo. Low stress, great for beginners.
Example: 8 miles total—6 miles easy, 2 miles @ tempo
Moderate-to-Fast Progression
Start at marathon pace, build through half marathon pace to threshold. Race-specific for marathoners.
Example: 10 miles—4 @ MP, 3 @ HMP, 3 @ T pace
Three-Stage Progression
Easy → Moderate → Tempo in thirds. Classic structure that builds progressively.
Example: 9 miles—3 easy, 3 moderate, 3 @ tempo
Why Progressions Work
By starting easy, you accumulate fatigue before hitting threshold pace. This simulates late-race conditions when you need to maintain or increase pace on tired legs. Many elite runners use progressions as their primary tempo format.
Programming Tempo Workouts
How you fit tempo workouts into your training week affects their effectiveness and your recovery. Strategic placement maximizes benefit while preventing overtraining.
Weekly Placement
- Space from other hard workouts: 48-72 hours between quality sessions
- Don't do before long runs: Allow recovery for your key long run
- Mid-week works well: Tuesday or Wednesday for most schedules
- Can combine with long run: Tempo miles within a long run (advanced)
Sample Training Weeks
Intermediate (40 miles/week)
- Mon: Rest or easy
- Tue: Tempo (5-6 mi total)
- Wed: Easy 5 mi
- Thu: Intervals
- Fri: Rest or easy 3
- Sat: Long run 12-14 mi
- Sun: Easy 6-8 mi
Advanced (60 miles/week)
- Mon: Easy 7 mi
- Tue: Cruise intervals (8 mi)
- Wed: Easy 8 mi
- Thu: VO2max intervals
- Fri: Easy 6 mi
- Sat: Long run w/ tempo finish
- Sun: Easy 8-10 mi
Seasonal Progression
Build tempo volume and intensity gradually across your training cycle:
- Base Phase: Shorter tempos (15-20 min), focus on finding rhythm
- Build Phase: Increase tempo duration to 25-35 min or add cruise intervals
- Peak Phase: Race-specific tempos, progressions, or combined with intervals
- Taper: Reduce volume but maintain some threshold intensity
Common Tempo Mistakes
Running Too Fast
The most common error. If you're gasping, struggling to maintain form, or can't complete the workout, you're running above threshold. Slow down—the tempo should feel challenging but sustainable.
Starting Too Fast
Even at correct average pace, starting too fast leads to fade. Start 5-10 seconds slower than target and settle into rhythm. The second half should feel slightly harder than the first, not dramatically harder.
Skipping Warm-Up
Jumping straight into tempo pace stresses cold muscles and makes the effort feel harder than it should. Always warm up 10-15 minutes with easy running and strides before tempo work.
Doing Tempos Too Often
More isn't always better. 1-2 threshold-intensity workouts per week is enough for most runners. Too many hard efforts leads to cumulative fatigue, stagnation, or injury.
Ignoring Conditions
Threshold pace varies with heat, humidity, wind, and terrain. Adjust by perceived effort and heart rate rather than hitting an exact pace on challenging days. A tempo in 90°F heat will be slower than in 60°F.
Frequently Asked Questions
What is tempo run pace?
Tempo pace is approximately your lactate threshold pace—the fastest pace you can sustain for about an hour in race conditions. It typically feels "comfortably hard"—you can speak in short sentences but not hold a conversation. For most runners, tempo pace is about 25-30 seconds per mile slower than 5K race pace, or roughly 15-20 seconds per mile faster than marathon pace.
How long should a tempo run be?
Classic tempo runs range from 20-40 minutes at threshold pace. Beginners should start with 15-20 minutes and progress to 30-40 minutes over time. The sweet spot for most runners is 20-30 minutes of sustained threshold running. For longer threshold work, use cruise intervals (repeat efforts with short rest) totaling 30-60 minutes of work.
What's the difference between tempo and threshold runs?
The terms are often used interchangeably, but technically: "Threshold" refers to the physiological lactate threshold pace. "Tempo" traditionally means any sustained hard effort, which may be at or slightly slower than threshold. In practice, most coaches use them synonymously to describe runs at or near lactate threshold pace.
How often should I do tempo runs?
Most runners benefit from 1-2 threshold-intensity workouts per week during focused training. For beginners, start with one tempo run every 7-10 days. Advanced runners can handle two threshold sessions per week if properly spaced and recovered. Always allow 48-72 hours of easy running between hard workouts.
What are cruise intervals?
Cruise intervals are repeat efforts at threshold pace with short recovery jogs. Developed by Jack Daniels, they allow you to accumulate more time at threshold pace than a continuous tempo run. A classic example is 4-6 x 1 mile at threshold pace with 1 minute jog recovery. The short rest keeps lactate elevated while allowing just enough recovery to maintain pace.
Embrace the Comfortably Hard
Tempo runs are where race fitness is built. They teach your body to run faster for longer, and your mind to embrace sustained effort. The "comfortably hard" intensity is the sweet spot where you're pushing your limits without breaking down.
Start conservatively, progress gradually, and respect the recovery that makes hard work productive. Over weeks and months, you'll notice threshold pace becoming marathon pace, and races feeling more controlled and manageable.
Remember: the goal isn't to survive tempo runs—it's to master them. When you finish feeling like you could have done a bit more, you've nailed it.
Related Articles
📊 Optimize Your Training
Use our free calculators to plan your runs: