From Start Line to T2: 10 Ironman Bike Sessions That Get Results!
Wondering how to train for the most demanding part of your Ironman?
Training for an Ironman is a massive undertaking, and building a rock-solid cycling foundation is crucial to success. The bike leg alone covers 180.2 km (112 miles) — and how you perform on the bike can make or break your race day.
Why Your Ironman Bike Training Matters
Cycling is the longest discipline in an Ironman triathlon, both in distance and in time spent racing. Nailing your bike training improves not only your bike split but also sets you up for a strong marathon. Poor bike pacing, lack of endurance, or nutrition mistakes can destroy your run.
That’s why it’s critical to balance long aerobic rides, race-specific intervals, strength work, and nutrition practice. Here’s how to structure your sessions for success!
In this post, we’ll dive into 10 essential Ironman bike sessions that build endurance, strength, race-specific fitness, and confidence for the big day!
The 10 Essential Ironman Bike Sessions
1. Long Endurance Ride
Purpose: Build aerobic depth and race-day stamina.
Warm-up:
15–20 min easy spin
Main Set:
4–6 hours in Zone 2 (55–75% FTP)
Cool-down:
10–15 min easy spin
Focus: Builds aerobic endurance and prepares your body for sustained efforts. Practice your race nutrition plan during these rides.
2. Race Pace Simulation
Purpose: Practice race execution under realistic conditions.
Warm-up:
60 min easy (Zone 2)
Main Set:
2–3 sets of:
45 min at Ironman pace (70–80% FTP)
15 min easy spin
Cool-down:
30–45 min easy spin
Focus: Dial in your race pace, fueling, and mental focus.
3. Brick Session (Bike + Run)
Purpose: Build confidence and pacing off the bike.
Warm-up (Bike):
15–20 min easy spin
Main Set (Bike):
3–4 hours at 70–80% FTP
Transition: 5 min easy jog
Main Set (Run):
30–60 min Zone 2–3
Cool-down (Run):
5–10 min easy jog
Focus: Practice running off the bike while fatigued. Simulate race-day transitions and pacing.
4. Over-Under Intervals
Purpose: Sharpen fitness for surges, hills, and packs.
Warm-up:
15–20 min easy spin
Main Set:
3–4 x (10 min @ 85% FTP + 5 min @ 95% FTP)
Cool-down:
10–15 min easy spin
Focus: Boosts muscular endurance and the ability to recover from surges.
5. Sweet Spot Tempo Ride
Purpose: Develop efficient, sustainable race power.
Warm-up:
15–20 min easy spin
Main Set:
3 x (30–40 min @ 80–90% FTP, 10 min easy between)
Cool-down:
10–15 min easy spin
Focus: Enhances race-day power, efficiency, and pacing consistency.
6. VO2 Max Intervals
Purpose: Improve high-end aerobic capacity and toughness.
Warm-up:
15–20 min easy spin
Main Set:
5–6 x 3–5 min @ 110–120% FTP with 5 min recovery
Cool-down:
10–15 min easy spin
Focus: Elevates your aerobic ceiling, helping you manage tough race sections and headwinds.
7. Strength Ride (Big Gear Work)
Purpose: Build raw strength and low-cadence power.
Warm-up:
15–20 min easy spin
Main Set:
6 x 5 min @ low cadence (50–60 rpm) and high resistance, with 3 min recovery
Cool-down:
10–15 min easy spin
Focus: Builds brute leg strength and fatigue resistance.
8. Hill Repeats
Purpose: Build climbing strength and mental grit.
Warm-up:
15–20 min easy spin
Main Set:
6–8 x 4–6 min uphill @ 90–100% FTP; recover on descent
Cool-down:
10–15 min easy spin
Focus: Develops climbing ability, muscular stamina, and mental toughness.
9. Steady Endurance Ride
Purpose: Practice smooth pacing and in-ride fueling.
Warm-up:
15–20 min easy spin
Main Set:
3–4 hours at Zone 2 (55–75% FTP), steady cadence (85–95 rpm), minimal stops
Cool-down:
10–15 min easy spin
Focus: Reinforces race-day pacing, nutrition strategies, and mental patience.
10. Race Nutrition Practice Ride
Purpose: Final dress rehearsal for fueling on race day.
Warm-up:
15–20 min easy spin
Main Set:
3–5 hours @ 70–80% FTP with full race-day nutrition and hydration strategy
Cool-down:
10–15 min easy spin
Focus: Test your complete race-day fueling plan to avoid GI distress.
Bonus Tip: Mix Indoor and Outdoor Sessions
Indoor trainers allow precise control over efforts and intervals, while outdoor rides develop handling skills and real-world adaptation. Incorporate both for a complete cycling program!
Remember: Consistency, progressive overload, and smart recovery are the keys to building your Ironman bike fitness.
FAQs About Ironman Bike Training
How many bike sessions per week for Ironman?
Most athletes train 3–4 bike sessions per week, balancing long rides, intervals, and race simulation.
What FTP should I aim for for Ironman?
There’s no single target FTP — it depends on your background. However, most aim to race at around 65–75% of FTP for the Ironman distance.
How important is bike nutrition practice?
Critical! You must train your gut to handle calories, fluids, and electrolytes under exertion to avoid bonking or GI issues on race day.
Final Thoughts
Mastering the Ironman bike leg is all about patience, consistency, and smart training structure. Use these 10 sessions to build your endurance, power, and confidence — and set yourself up for a strong marathon too!
Which of these key bike sessions will you focus on first to level up your Ironman training?
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.