Ironman 70.3 Bike Training: 10 Threshold Sessions

Summary:
Threshold bike training is key to riding strong and steady over 90 km at Ironman 70.3. These 10 structured sessions target Zone 4 effort, building power, control and fatigue resistance. Training at 87–93% max heart rate or 91–105% FTP helps develop your ability to hold race pace without fading. Aim for a smooth cadence, steady pacing and consistent effort across reps. With the right structure and metrics, you’ll be ready to deliver a powerful, efficient ride on race day.

Why Threshold Bike Training Matters for Ironman 70.3

Threshold bike training builds the sustained power, pacing control, and endurance you need to dominate the 90 km ride and set yourself up for a great run. The bike leg of Ironman 70.3 isn’t just about endurance — it’s about sustaining a strong, efficient pace while managing fatigue.

Threshold training targets the sweet spot where you can push hard without burning out, improving functional threshold power (FTP), aerobic capacity and mental resilience — all vital for a successful bike split and a strong finish.Structured threshold sessions teach you to hold a solid effort even late into the ride when it matters most.

These 10 essential threshold bike sessions will sharpen your race fitness, improve your lactate threshold, and help you ride with confidence on race day!

Metrics Guide for Threshold Bike Training

• Heart Rate (Zone 4): 87–93% of max HR

• Power (FTP): 91–105% of FTP

• Cadence Target: 85–95 RPM

• RPE (Effort Feel): 7–8 out of 10 — hard but controlled

• Use the FLJUGA Heart Rate Calculator to find your exact training zones.

Use these metrics to keep your sessions focused, controlled, and race-specific.

1. Classic Threshold Intervals

Purpose: Sustain race effort efficiently over intervals.

Warm-up: 15 min easy spin
Main Set: 5 x 5 min at Zone 4 (race pace), 3 min recovery
Cool-down: 15 min easy spin

2. Over-Unders

Purpose: Handle surges and recover quickly without losing speed.

Warm-up: 15 min easy spin
Main Set: 4 x (3 min at Zone 4, 2 min at Zone 3), 3 min recovery between sets
Cool-down: 15 min easy spin

3. 20-Minute Threshold Test

Purpose: Assess FTP and calibrate training zones.

Warm-up: 15 min easy spin
Main Set: 20 min all-out threshold effort (Zone 4)
Cool-down: 15 min easy spin

4. Long Threshold Ride

Purpose: Build race-day stamina and endurance.

Warm-up: 15 min easy spin
Main Set: 60 min steady at Zone 3–4 (70.3 race pace)
Cool-down: 15 min easy spin

5. Pyramid Intervals

Purpose: Develop pacing skills across different intensities.

Warm-up: 15 min easy spin
Main Set:
5 min Zone 4
4 min Zone 3
3 min Zone 4
2 min Zone 3
1 min Zone 4
5 min recovery after the pyramid
Cool-down: 15 min easy spin

6. Tempo and Threshold Intervals

Purpose: Blend endurance and race-effort intensity.

Warm-up: 15 min easy spin
Main Set:
20 min at Zone 3 (tempo)
5 x 2 min at Zone 4 (threshold) with 2 min recovery
Cool-down: 15 min easy spin

7. Negative Split Ride

Purpose: Teach controlled pacing and strong finishes.

Warm-up: 15 min easy spin
Main Set:
90 min ride:
First 45 min at Zone 3
Last 45 min at Zone 4
Cool-down: 15 min easy spin

8. Time Trial Efforts

Purpose: Build sustained high-effort performance.

Warm-up: 15 min easy spin
Main Set: 3 x 10 min at Zone 4, 5 min easy recovery between efforts
Cool-down: 15 min easy spin

9. Hill Threshold Training

Purpose: Build power and lactate tolerance.

Warm-up: 15 min easy spin
Main Set: 6 x 5 min climbs at Zone 4 effort, 5 min easy spin recovery
Cool-down: 15 min easy spin

10. Taper Threshold Ride (7–10 Days Pre-Race)

Purpose: Maintain fitness and sharpness without building fatigue.

Warm-up: 15 min easy spin
Main Set: 40 min at Zone 3–4 (controlled effort)
Cool-down: 15 min easy spin

Final Tips for Threshold Bike Training

• Pace with Power or Heart Rate: Stay consistent, especially during intervals.

• Stay Aero: Practice maintaining race position throughout threshold efforts.

• Fuel Properly: Train your gut to handle calories and fluids at race pace intensities.

Threshold training on the bike will set you up for a faster ride, better pacing, and a stronger run on race day!

FAQs: Threshold Bike Training for Ironman 70.3

How often should I include threshold bike sessions?

Most athletes include 1–2 threshold rides per week, balanced with endurance rides and recovery spins.

What’s the difference between threshold and tempo training?

Threshold is harder — right around lactate threshold (Zone 4), while tempo is slightly easier (Zone 3).

Should I do threshold intervals in aero position?

Absolutely — training at race effort in aero helps build the strength and comfort needed for race day.

Final Thoughts

Threshold bike training is essential for building power, endurance, and race-day pacing at Ironman 70.3. These sessions train your body to hold strong, efficient efforts even deep into the ride — exactly when fatigue sets in.

By consistently targeting Zone 4, you'll improve your ability to ride faster without tipping into exhaustion. Every rep, every effort, every interval adds up to a more confident, controlled and powerful performance on race day. Stay focused, track your metrics, and train with purpose.

Which threshold bike session will you add to your training plan to level up your 90 km performance?

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.