Crush the Marathon: 10 Ironman Run Threshold Sessions!
Want to run faster off the bike and hold pace deep into the marathon?
Threshold running is critical in Ironman training as it helps build sustained speed, endurance, and efficiency while improving your ability to clear lactate and maintain a strong pace deep into the marathon.
Below are key threshold sessions designed to maximise your race-day performance.
1. Classic Threshold Intervals
Purpose: Improves lactate clearance and enhances race-day pacing.
Session:
• Warm-up: 15 min easy run
• 4–5 x 10 min at threshold pace (Zone 4 or ~85-90% HR max), 2 min easy jog recovery
• Cool-down: 10 min easy jog
Focus: Holding a consistent, controlled effort just below your max sustainable pace.
2. Progressive Threshold Run
Purpose: Simulates race fatigue by increasing intensity over time.
Session:
• Warm-up: 15 min easy run
• 4 x 10 min at increasing effort:
• 1st: Upper Zone 3 (steady)
• 2nd: Low Zone 4 (moderate-hard)
• 3rd & 4th: Threshold pace (Zone 4)
• 10 min cool-down
Focus: Building resilience and pacing awareness for the latter stages of an Ironman run.
3. Long Run with Threshold Surges
Purpose: Mimics race conditions by adding intensity to a long aerobic session.
Session:
• 90–120 min long run:
• 20 min easy warm-up
• Every 15 minutes, insert 2 min at threshold effort
• Last 20 min: Run at marathon race pace
• Cool-down: 5–10 min easy jog
Focus: Practicing pace changes and endurance while maintaining form.
4. Tempo + Threshold Combo
Purpose: Blends sustained effort with threshold work for efficiency and endurance.
Session:
• Warm-up: 15 min easy jog
• 20 min tempo effort (Zone 3)
• 4 x 5 min at threshold pace (Zone 4), 90 sec recovery
• 10 min cool-down
Focus: Managing fatigue and maintaining good biomechanics under stress.
5. Broken Threshold Repeats
Purpose: Develops sustained speed without overloading the legs.
Session:
• Warm-up: 15 min easy run
• 6–8 x 3 min at threshold pace, 60 sec recovery jog
• Cool-down: 10 min easy jog
Focus: Holding consistent threshold pace across all reps without fading.
6. Threshold Hill Repeats
Purpose: Builds leg strength and threshold endurance.
Session:
• Warm-up: 15 min easy run
• 6 x 3–4 min uphill at threshold effort, jog down for recovery
• 10 min cool-down
Focus: Running strong and relaxed while maintaining cadence.
7. Marathon Pace + Threshold Run
Purpose: Combines race pacing with a threshold push to mimic late-race demands.
Session:
• Warm-up: 15 min easy run
• 45 min at Ironman marathon pace (Zone 2-3)
• 15 min at threshold effort (Zone 4)
• 5–10 min easy cool-down
Focus: Practicing strong finishes on tired legs.
8. Descending Threshold Intervals
Purpose: Improves ability to finish strong by increasing pace with each rep.
Session:
• Warm-up: 15 min easy run
• 4 x 8 min at descending paces (slightly faster each rep), 90 sec recovery
• 10 min cool-down
Focus: Building mental and physical endurance for negative splitting.
9. Threshold-Based Fartlek Run
Purpose: Improves speed endurance with varied efforts.
Session:
• Warm-up: 15 min easy run
• 4 rounds of:
• 3 min at threshold pace
• 2 min at Ironman marathon pace
• 1 min at 5K pace
• 10 min cool-down
Focus: Managing effort shifts without breaking rhythm.
10. Taper Threshold Tune-Up (7–10 days before race day)
Purpose: Maintains sharpness without overloading before race day.
Session:
• Warm-up: 15 min easy jog
• 3 x 6 min at threshold pace, 2 min easy jog recovery
• 10 min cool-down
Focus: Staying smooth, fast, and confident leading into race day.
Final Thoughts:
These threshold sessions help improve speed, endurance, and pacing for the Ironman run. Integrating them 1–2 times per week in a structured plan will help you hold race pace longer and finish strong.
Add these sessions to your weekly plan and turn strength and speed into your race-day weapon!
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 personalised advice.