Marathon Training: 10 Zone 4 / Threshold Workouts
Summary
These 10 Zone 4 / Threshold workouts target 87–93% max heart rate (RPE 7–8) to build speed, efficiency and fatigue resistance during marathon training. Each session trains your body to clear lactate, hold pace under pressure and maintain performance when it matters most. Ideal for weeks 5–14 of a 16-week plan, threshold workouts make marathon pace feel smoother and stronger — even in the final 10K.
Why Threshold Training Matters for the Marathon
Marathon success isn’t just about long runs. To truly improve, runners need to train the systems that allow them to hold pace under fatigue. That’s where threshold training comes in.
Threshold running targets the point just below where your body begins to accumulate lactate faster than it can clear it. In practical terms, this is the hardest pace you can sustain for about an hour — also known as Zone 4 / Threshold.
Training in this zone builds:
Lactate clearance capacity
Pacing control at high aerobic loads
Mental resilience in race conditions
Efficiency at or near marathon pace
Threshold work helps you make race pace feel more manageable and gives you a gear that’s fast but sustainable — crucial when you're 32 km into a marathon and the effort starts to bite.
What Is Zone 4 Running?
Zone 4, or lactate threshold zone, typically falls at:
87–93% of your max heart rate
RPE 7–8 (hard but sustainable)
A pace that’s quicker than marathon pace, but not quite 10K effort
It’s often called “comfortably hard” — where talking becomes difficult but manageable in short phrases.
Zone 4 is where your body learns to clear lactate, maintain speed, and delay the onset of exhaustion. This makes it ideal for race-specific marathon preparation.
Want to check your Zone 4 range? Use the FLJUGA calculator to calculate your zones.
How to Use These Threshold Sessions
Use one threshold session per week during your main build phase — usually weeks 5–14 of a 16-week marathon plan. Avoid doing threshold the day before or after your long run, and be sure to warm up and cool down properly in each session.
10 Threshold Sessions for Marathon Training
1. Classic Threshold Blocks
Purpose: Build lactate control with repeatable Zone 4 efforts
Warm-Up: 15 min jog
Main Set: 3 x 10 min @ Zone 4 (3 min jog between)
Cool-Down: 10 min jog
2. Long Threshold Finish
Purpose: Practice pushing threshold when tired
Warm-Up: 15 min jog
Main Set: 70 min @ Zone 2 – 20 min @ Zone 4
Cool-Down: 10 min jog
3. Split Threshold Sets
Purpose: Make long reps mentally and physically manageable
Warm-Up: 12 min jog
Main Set:
2 x (6 min @ Zone 4 – 2 min jog – 4 min @ Zone 4 – 2 min jog – 2 min @ Zone 4) (2 min jog between sets)
Cool-Down: 10 min jog
4. Progressive Threshold Run
Purpose: Build into Zone 4 for controlled fatigue resistance
Warm-Up: 10 min jog
Main Set: 10 min @ Zone 2 – 10 min @ Zone 3 – 20 min @ Zone 4
Cool-Down: 10 min jog
5. Broken Threshold Repeats
Purpose: Short recoveries challenge repeatability at threshold
Warm-Up: 15 min jog
Main Set: 6 x 6 min @ Zone 4 (1 min jog recoveries)
Cool-Down: 10 min jog
6. Cruise Interval Session
Purpose: Develop rhythm and repeatable pace
Warm-Up: 15 min jog
Main Set: 5 x 8 min @ Zone 4 (2 min jog between)
Cool-Down: 10 min jog
7. Pyramid Threshold Set
Purpose: Pace control across varying durations
Warm-Up: 15 min jog
Main Set: 5 min – 10 min – 15 min – 10 min – 5 min @ Zone 4 (2 min jog between)
Cool-Down: 10 min jog
8. Marathon Pace + Threshold Combo
Purpose: Transition between race pace and controlled threshold
Warm-Up: 15 min jog
Main Set: 20 min @ Zone 3 – 20 min @ Zone 4
Cool-Down: 10 min jog
9. Alternating Threshold Blocks
Purpose: Mix steady efforts with threshold surges
Warm-Up: 15 min jog
Main Set: 5 x (4 min @ Zone 3 – 4 min @ Zone 4)
Cool-Down: 10 min jog
10. Big Block Threshold
Purpose: Simulate sustained race effort
Warm-Up: 15 min jog
Main Set: 40 min continuous @ Zone 4
Cool-Down: 10 min jog
Mini FAQ: Threshold Training in Marathon Plans
What exactly is Zone 4 / Threshold training for marathon runners?
It’s structured running at lactate threshold — where your body works hard but stays just under the tipping point of fatigue. Zone 4 effort.
When should I do these sessions?
Once a week, ideally 2–3 days away from your long run.
Should I go by pace, heart rate, or feel?
Use all three. Heart rate and pace give structure, but perceived effort is the best guide when conditions vary.
How long should threshold intervals be?
Start with 5–10 minute intervals and build toward longer blocks of 20–40 minutes.
What if I can’t hit the pace?
Focus on effort, not perfection. The point is to work at a sustained “hard but controlled” intensity.
Final Thoughts
Threshold sessions are one of the most powerful tools marathoners can use to build speed and durability. These Zone 4 workouts target your body’s ability to clear lactate and hold effort under pressure — exactly what you need in the second half of the race. By adding these sessions into your weekly schedule, you’ll not only run faster, but smarter. Use them consistently, listen to your body, and watch your marathon pace start to feel easier over time.
Are you staying consistent, trusting your training and ready to set a new personal best?
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.
