Half Marathon Training: 10 Zone 4 / Threshold Workouts
Summary:
Zone 4 training (87–93% max HR, RPE 7–8) targets your lactate threshold, the edge of sustainable effort. These sessions build control, resilience and late-race strength. For half marathon runners, Zone 4 teaches you to stay composed when the pace rises and finish strong without fading.
What Is Zone 4/Threshold Training?
Zone 4 typically sits between 87–93% of your maximum heart rate and feels like 7–8 out of 10 on the RPE scale. Breathing is hard, conversation disappears and your focus has to stay tight. It is the kind of effort you can hold only with discipline. You sit just under your limit, pushing with intent but still maintaining control. During this phase, lactate accumulation continues to increase to the point where it is around one’s lactate threshold, which is why the effort feels firm, rising and demanding without tipping into all-out strain.
Threshold training is one of the most productive zones for half marathon preparation. It teaches you how to manage strong effort, clear lactate efficiently and stay composed when intensity lifts. This is where you build the controlled discomfort and race-ready strength needed to hold pace through the toughest sections of the half marathon.
Why These Sessions Work
Zone 4 training lifts your lactate threshold and helps you stay in control when the effort grows. These workouts sharpen your ability to manage rising intensity without breaking your rhythm. They also strengthen the way you clear fatigue so you can keep moving well when the pace asks more from you. For half marathon runners, this zone builds the kind of steady confidence that lasts through long stretches of hard running and supports a strong push when the race begins to tighten.
How Do You Know You Are in Zone 4?
Zone 4 sits at the edge of comfort, where effort becomes firm and deliberate. You are working hard, yet still steady enough to keep your stride organised and your thoughts clear. Breathing deepens, talking stops and the effort builds in a way that demands full attention without spilling into strain. For half marathon runners, this is the zone that teaches you how to stay strong when the pace rises and how to manage intensity without losing control.
How to stay in the right range:
Heart rate: 87–93% of max
Talk test: Only short, clipped phrases are possible
Effort: 7–8 out of 10, challenging but consistent
A true threshold effort feels like something you could hold for 20 to 60 minutes with focus and discipline. The intensity grows, yet rhythm remains intact and you maintain enough clarity to control your pacing. For the half marathon, this zone builds the resilience needed for long stretches of strong running and prepares you for the points in the race where pace, patience and mental strength come together.
Check out: FLJUGA Heart Rate Zone Calculators
10 Threshold Workouts for Half Marathon Runners
1. Standard Threshold Repeats
Purpose: Repeatable, controlled effort to build strength.
Warm-Up: 12 min jog + 4 strides
Main Set: 4 x 8 min @ Zone 4 (2 min jog)
Cool-Down: 10 min jog
2. Progressive Threshold Blocks
Purpose: Builds intensity gradually to simulate race fatigue.
Warm-Up: 15 min jog
Main Set: 6 min - 8 min - 10 min @ Zone 4 (90 sec jog between)
Cool-Down: 10 min jog
3. Broken Threshold Sets
Purpose: Maintains high effort without overloading.
Warm-Up: 12 min jog + drills
Main Set: 3 x (5 min + 3 min) @ Zone 4 (1 min between reps, 2 min between sets)
Cool-Down: 10 min jog
4. Threshold + Tempo Blend
Purpose: Transitions from steady effort into race-like intensity.
Warm-Up: 12 min jog
Main Set:
10 min @ Zone 3
2 x 7 min @ Zone 4 (2 min jog)Cool-Down: 10 min jog
5. Long Threshold Repeats
Purpose: Pushes your ability to hold form over longer efforts.
Warm-Up: 15 min jog
Main Set: 2 x 12 min @ Zone 4 (3 min jog)
Cool-Down: 10 min jog
6. Fast Finish Threshold
Purpose: Trains control early, strength late.
Warm-Up: 12 min jog
Main Set: 10 min Zone 2 - 8 min @ Zone 3 - 4 min @ Zone 4
Cool-Down: 10 min jog
7. Short Threshold Intervals
Purpose: Sharp and focused, with active recovery.
Warm-Up: 10 min jog
Main Set: 6 x 4 min @ Zone 4 (90 sec jog)
Cool-Down: 10 min jog
8. Hill Threshold Session
Purpose: Builds strength while staying at controlled intensity.
Warm-Up: 15 min jog + hill drills
Main Set: 5 x 4 min uphill @ Zone 4 (walk/jog down)
Cool-Down: 10 min jog
9. Threshold Pyramid
Purpose: Balances pacing and effort through varied lengths.
Warm-Up: 15 min jog
Main Set: 5 min - 6 min - 7 min - 6 min - 5 min @ Zone 4 (2 min jog)
Cool-Down: 10 min jog
10. 90-Second Threshold Repeats
Purpose: Adds volume without overreaching.
Warm-Up: 10 min jog
Main Set: 10 x 90 sec @ Zone 4 (60 sec jog)
Cool-Down: 10 min jog
Common Mistakes in Zone 4 Training for Half Marathon Runners
Zone 4 is where half marathon strength becomes race-ready control. It sharpens your ability to handle firm, sustained effort without slipping into strain. Yet because this zone sits close to your limit, it is easy to overreach or lose the smooth pacing these sessions rely on. Most mistakes happen when runners confuse threshold with pushing hard, rather than holding a focused and steady intensity.
What to watch out for:
Starting the first rep too fast: Overshooting early effort spikes fatigue and stops you from keeping consistent threshold across the session.
Letting the work feel harder than it should: Threshold should feel tough but manageable. When the effort starts to feel like a push, you are above the zone.
Losing rhythm in your stride: When your movement becomes uneven or disconnected, you are above sustainable threshold effort.
Cutting recoveries too short: Threshold work still needs structured rest to stay controlled. Rushing recovery pushes the intensity into the wrong zone.
Running Zone 4 on heavy legs: Threshold requires clarity and stability. Fatigued legs make the effort feel harder and shift the work into unproductive intensity.
Zone 4 sessions deliver their best results when the effort stays firm, smooth and repeatable. Hold the line, respect the recoveries and aim for consistent quality from the first rep to the last. When done right, threshold training becomes the foundation that supports strong, confident half marathon pacing.
FAQ: Zone 4 / Threshold Training for Half Marathon
What is Zone 4 in half marathon training?
Zone 4 is your threshold zone. It is a firm, focused effort that feels demanding but still controlled. Heart rate usually sits between 87–93% of your maximum.
How should Zone 4 feel during training?
Breathing is heavy and speech is limited. The effort rises quickly yet remains steady enough to manage with concentration.
How often should I include Zone 4 sessions?
Once per week works well for most runners. Threshold training needs space around it to stay effective.
Does Zone 4 training help with race performance?
Yes. It strengthens your ability to run strong through tougher sections of the half marathon and helps you stay composed when the pace increases.
Do easy runs still matter if I train in Zone 4?
Absolutely. Easy running supports recovery and helps your body absorb the benefits of threshold work.
FURTHER READING: BUILD YOUR HALF MARATHON BASE
Half Marathon Training: What Is Zone 1 / Recovery?
Half Marathon Training: What Is Zone 2 / Endurance?
Half Marathon Training: What Is Zone 3 / Tempo?
Half Marathon Training: What Is Zone 4 / Threshold?
Half Marathon Training: What Is Zone 5 / VO2 Max?
Training Sessions:
Half Marathon Training: 10 Essential Sessions
Half Marathon Training: 10 Zone 3 / Tempo Workouts
Half Marathon Training: 10 Zone 5 / VO2 Max Workouts
Final Thoughts
Zone 4 is the effort that prepares you for the real demands of the half marathon. These sessions build controlled strength so you can handle rising intensity without losing your rhythm. When the course shifts or the pressure lifts or the race begins to tighten, Zone 4 gives you the stability to respond with confidence. Train this zone well and you carry a steady, reliable effort all the way to the finish.
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.
