Half Marathon Training: 10 Zone 4/Threshold Sessions
Summary
Zone 4/Threshold is where your race pace begins to sharpen. These sessions develop the ability to hold strong effort without tipping into exhaustion. For half marathon runners, Zone 4 is the zone that prepares you to stay efficient and composed when the pace increases — especially in the second half of the race. Threshold training isn’t about top speed — it’s about top control. Zone 4 sits at your lactate threshold, where breathing deepens, focus narrows, and your body starts to accumulate fatigue. For the half marathon, this zone teaches you how to stay calm under pressure, maintain form when the pace rises, and build strength that holds in the late miles.
What Is Zone 4/Threshold Training?
Zone 4 typically ranges between 87–93% of your maximum heart rate and feels like a 7–8 out of 10 on the RPE scale. You’re breathing hard, conversation is gone, and focus must stay sharp. It’s the kind of effort that requires management — you can hold it, but only with precision. When you’re in Zone 4, you feel just beneath your limit. You’re pushing with purpose. It’s controlled discomfort and it’s one of the most productive zones for preparing to race well at half marathon intensity.
Why These Sessions Work
Zone 4 workouts increase your lactate threshold, improve fatigue resistance, and develop your ability to run fast with control. These sessions teach you to handle pressure, respond to pacing shifts, and run strong without slipping into overexertion. For half marathoners, this is essential — especially when racing against both distance and time.
10 Threshold Workouts for Half Marathon Runners
1. Standard Threshold Repeats
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
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
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
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
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
Trains control early, strength late.
Warm-Up: 12 min jog
Main Set: 10 min steady → 8 min @ Zone 3 → 4 min @ Zone 4
Cool-Down: 10 min jog
7. Short Threshold Intervals
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
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
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
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
FAQ
How do I know I’m in Zone 4?
You’re breathing hard and focused. You can’t talk. It feels like you’re holding just below your limit — strong, but needing control to stay there.
How often should I train in Zone 4 during a half marathon build?
One session per week is effective. Add a second only if recovery, volume, and training experience allow.
How do I calculate my Zone 4 heart rate?
Use FLJUGA’s free heart rate zone calculator to find your personalised ranges and train with precision.
Final Thoughts
Zone 4 is where controlled speed becomes race-ready. These sessions prepare you for the demands of racing hard over distance — not with chaos, but with composure. When the pace picks up, or the hill hits, or the line approaches, Zone 4 is what helps you respond without breaking.
Can you hold strong when your race starts to press back?
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.