Ironman Training: 10 Zone 3 / Tempo Example Run Sessions
Summary:
Zone 3 run training, typically performed at 80–87% of maximum heart rate and an RPE of 5–6, plays a key role in Ironman run development by building sustainable pace, efficiency and fatigue resistance. These tempo workouts sit between easy endurance and threshold, allowing athletes to accumulate quality running without excessive recovery cost. Rather than chasing intensity, Zone 3 training improves pacing control and durability, helping athletes maintain smooth, controlled running after the bike and across the marathon distance.
Why Ironman Tempo Run Training Matters
Tempo training plays a central role in Ironman preparation because it develops the ability to sustain controlled effort for long periods without accumulating excessive fatigue. While endurance running builds the aerobic foundation and threshold work raises the upper limit of sustainable pace, Zone 3 training occupies the space just above easy endurance where control, efficiency and pacing discipline are refined. This makes tempo work especially valuable for teaching athletes how to manage effort without forcing intensity or relying on short bursts of speed.
Zone 3 run training targets an effort that feels purposeful yet controlled. This is a slightly more intense version of Zone 2. During this phase, lactate production increases but can still be cleared effectively. Breathing remains elevated but stable, allowing athletes to focus on posture and rhythm under manageable fatigue. This makes tempo training well suited to accumulating quality running volume without excessive recovery cost. Repeated exposure to tempo training improves durability, reduces pacing drift and supports smoother running late in long efforts and off the bike.
This may help you: Triathlon Training: What Is Zone 3 / Tempo Workouts?
Metrics Guide for Tempo Run Training
Understanding how tempo run training is measured helps ensure sessions are executed at the correct intensity and deliver their intended effect. Zone 3 sits between easy endurance and threshold, which makes clear metrics essential for keeping effort controlled rather than drifting too hard or becoming too relaxed.
Heart rate measures how frequently the heart beats per minute and reflects the body’s internal response to effort. In run training, it is used to estimate how hard the cardiovascular system is working relative to an athlete’s maximum or threshold heart rate. RPE or Rate of Perceived Exertion, describes how hard a session feels to the athlete on a subjective scale and provides a practical reference for translating internal sensations of effort into usable training intensity.
Tempo Run Metrics
Heart Rate: 80–87% of max HR
RPE: 5–6
Effort: Moderately hard
Use the FLJUGA Heart Rate Zone Calculator to find your exact Zone 3 range.
These metrics define an intensity that allows meaningful quality to be accumulated without excessive strain. Staying within this range ensures tempo sessions remain repeatable and support durability and pacing control. When effort is clearly defined and consistently respected, Zone 3 training becomes a reliable foundation for long-term Ironman run development rather than a grey-area effort that compromises recovery.
This may help you: Triathlon Training Zones 1–5 Explained: Why They Matter
10 Tempo Run Sessions for Ironman Training
1. Classic Tempo Run
Purpose: Develop sustained aerobic rhythm
Warm-Up: 15 min jog
Main Set: 40 min @ Zone 3
Cool-Down: 10 min jog
2. Tempo Blocks
Purpose: Make long efforts manageable with recovery
Warm-Up: 15 min jog
Main Set: 3 x 15 min @ Zone 3 (3 min jog between)
Cool-Down: 10 min jog
3. Tempo + Steady Combo
Purpose: Shift between moderate and strong aerobic effort
Warm-Up: 12 min jog
Main Set: 20 min @ Zone 2 – 30 min @ Zone 3
Cool-Down: 10 min jog
4. Progressive Tempo Run
Purpose: Build from easy to strong aerobic effort
Warm-Up: 15 min jog
Main Set: 10 min @ Zone 2 – 15 min @ low Zone 3 – 15 min @ upper Zone 3
Cool-Down: 10 min jog
5. Tempo Repeats
Purpose: Improve consistency over repeated aerobic intervals
Warm-Up: 15 min jog
Main Set: 4 x 10 min @ Zone 3 (2 min jog recoveries)
Cool-Down: 10 min jog
6. Mid-Long Tempo Run
Purpose: Tempo control over a longer duration
Warm-Up: 15 min jog
Main Set: 60 min @ Zone 3
Cool-Down: 10 min jog
7. Pyramid Tempo Set
Purpose: Pacing discipline at mixed durations
Warm-Up: 15 min jog
Main Set: 5 min – 10 min – 15 min – 10 min – 5 min @ Zone 3 (2 min jog between)
Cool-Down: 10 min jog
8. Tempo Sandwich
Purpose: Frame threshold work with aerobic pressure
Warm-Up: 15 min jog
Main Set: 20 min @ Zone 3 – 5 min @ Zone 4 – 20 min @ Zone 3
Cool-Down: 10 min jog
9. Broken Tempo Set
Purpose: High total volume with short rests
Warm-Up: 15 min jog
Main Set: 6 x 8 min @ Zone 3 (90 sec jog between)
Cool-Down: 10 min jog
10. Fast Finish Tempo
Purpose: Train late-race control and strength
Warm-Up: 15 min jog
Main Set: 40 min @ Zone 3 – 10 min @ Zone 4
Cool-Down: 10 min jog
Common Mistakes with Tempo Run Training
Tempo run sessions are highly effective for building sustainable pace and durability in Ironman preparation, but only when intensity remains disciplined and controlled. Because Zone 3 sits close to the boundary between easy endurance and threshold, small pacing errors can gradually change the training effect without being immediately obvious. Over time, this can lead to excessive fatigue or stalled progression rather than meaningful adaptation.
Running too hard:
The most common mistake is allowing tempo runs to drift toward threshold. When effort creeps beyond Zone 3, recovery demands increase and the session becomes harder to recover from. Tempo running should feel moderately hard but controlled, not forced or breathless, unless the session is intentionally designed to include Zone 4 work as part of threshold or higher-intensity training.Turning every steady run into tempo:
Replacing easy endurance runs with tempo effort increases overall training stress without clear benefit. Ironman preparation relies on a large volume of genuinely easy running, with tempo used selectively. When Zone 3 becomes the default intensity, fatigue accumulates quietly and consistency suffers.Letting effort fade late in the session:
Allowing pace or form to deteriorate toward the end of a tempo run reduces the quality of the work. Tempo sessions are about control and stability. Maintaining even effort matters more than finishing fast or extending the duration.Ignoring recovery between sessions:
Although tempo running is more sustainable than threshold work, it still carries a recovery cost. Stacking tempo sessions too closely together or pairing them with demanding workouts can reduce adaptation and increase injury risk.
When executed with patience and restraint, tempo run training builds efficiency, durability and confidence. Keeping effort controlled, respecting recovery and prioritising consistency ensures these sessions support Ironman run development rather than undermine it.
This may help you: How to Train for an Ironman: The Complete Training Guide
FAQ: Ironman Zone 3 / Tempo Run Training
What is Zone 3 run training?
Zone 3 run training involves steady, moderately hard efforts that build sustainable pace, efficiency and fatigue resistance without excessive recovery cost.
How does Zone 3 differ from Zone 2?
Zone 3 is slightly more intense than Zone 2, with higher breathing and effort, while still remaining controlled and repeatable.
How often should tempo runs be used in Ironman training?
Most Ironman athletes include one tempo run per week, depending on experience, recovery capacity and overall training load.
How long should Zone 3 efforts last?
Zone 3 efforts typically range from 20 to 60 minutes of total tempo work, depending on training phase and fitness level.
Should tempo runs feel hard?
Tempo runs should feel moderately hard but controlled, allowing stable breathing and consistent pacing throughout the session.
Can tempo runs drift into Zone 4?
Tempo runs should remain in Zone 3 unless the session is intentionally designed to include Zone 4 as part of threshold or higher-intensity training.
Where do tempo runs fit in the training week?
Tempo runs are placed so they are supported by easy sessions without compromising recovery or overall training balance.
FURTHER READING: BUILD YOUR MARATHON BASE
Running: Running Zones 1–5 Explained
Marathon Training: 10 Zone 5 / VO2 Max Workouts
Marathon Training: 10 Zone 4 / Threshold Workouts
Marathon Training: 10 Essential Sessions
Marathon Training: What Is Zone 3 / Tempo?
Final Thoughts
Zone 3 tempo run training plays a foundational role in Ironman preparation by developing sustainable pace, efficiency and fatigue resistance without placing excessive strain on the body. When used with intent, tempo sessions reinforce pacing discipline and controlled effort, helping athletes maintain smoother running as fatigue builds. The effectiveness of tempo training lies in restraint, with effort remaining moderately hard but controlled and supported by adequate recovery and genuinely easy running elsewhere in the week. When intensity is respected and sessions are placed carefully, Zone 3 run workouts become a reliable tool for building durability and long-term consistency rather than a source of unnecessary fatigue.
Always consult with a medical professional or certified coach before beginning any new training program. The information provided is for educational purposes only and is not a substitute for personalized advice.
