Triathlon Bike Training: What Is Zone 3 / Tempo?
SUMMARY:
Zone 3 — 76–90% of FTP, 80–87% max heart rate, RPE 5–6 — is the tempo zone in triathlon cycling. It builds muscular endurance, pacing control and sustainable power. These sessions help you develop race-day rhythm, ride strong over long distances and stay efficient under pressure.
What Is Zone 3 Cycling?
Zone 3 — also known as “tempo” or “sweet spot” — is that moderate-intensity cycling zone that lives between easy aerobic rides and full-throttle efforts. In the triathlon world, it can be both misunderstood and under-utilized.
While too much Zone 3 work can lead to fatigue if overdone, targeted Zone 3 training on the bike can bring big gains in muscular endurance, pacing control, and race readiness — especially for Olympic, 70.3, and Ironman athletes.
Zone 3 typically corresponds to 76–90% of FTP, 80–87% of max heart rate, and RPE 5–6. It’s a steady, challenging pace — one you can sustain for 45 to 90+ minutes with concentration, but not ease. You can still speak, but only in short phrases, and your legs gradually start to feel the load.
Zone 3 Cycling Metrics
FTP: 76–90%
Heart Rate: 80–87% of max HR
RPE: 5–6
Cadence: 80–95 RPM
Effort: Steady, controlled, moderately hard
Speaking Test: Can speak in short phrases, but not full sentences
Check your exact zones with FLJUGA’s free FTP and Heart Rate Calculators.
7 Benefits of Zone 3 Cycling for Triathletes!
1. Builds Muscular Endurance
Zone 3 targets your ability to sustain power over long periods, which is key for holding pace during triathlon bike legs — especially on rolling terrain or long flats.
2. Trains Race-Day Effort
Many triathletes race the bike portion in Zone 3 (especially in Olympic and Half Ironman events). Training here helps lock in your target race intensity.
3. Improves Lactate Clearance
Zone 3 riding boosts your body’s ability to tolerate and clear lactate, helping delay fatigue and extend your time at higher intensities.
4. Develops Fueling Strategies
Longer Zone 3 sessions offer the perfect chance to practice your nutrition plan — critical for dialing in hydration and carb intake during race-specific efforts.
5. Bridges Aerobic and Anaerobic Fitness
Zone 3 fills the gap between low-end aerobic work (Zone 2) and hard intervals (Zone 4+). This builds a more complete engine without overreaching.
6. Boosts Mental Grit and Focus
Riding at Zone 3 for long blocks teaches you how to manage discomfort and hold consistent output — a valuable skill on race day.
7. Time-Efficient Fitness Gains
When time is tight, Zone 3 rides offer more stimulus than Zone 2 without the extended recovery demands of threshold or VO2 work.
Example Zone 3 Bike Session
Warm-Up:
15–20 min easy spin + 3 × 30 sec pickups
Main Set:
2 × 20 min at Zone 3 (76–90% FTP or 80–87% HR),
4 min easy spin between
Cool-Down:
10–15 min easy spin
Progression Tip:
Progress to 3 × 20 or 2 × 30 min Zone 3 intervals as fitness improves.
For more tempo bike sessions, check out here.
When to Use Zone 3
Zone 3 work is best used during the build phase leading up to a race, when your goal is to develop sustainable strength and controlled effort. It fits well into long intervals, such as 2 × 20–30 minutes at Zone 3 with short recovery, helping to build endurance at a challenging but manageable pace.
You can also include Zone 3 in progressive long rides — starting in Zone 2 and finishing strong in Zone 3 — to mimic race-day fatigue. Brick workouts are another ideal time to incorporate Zone 3, allowing you to simulate race pacing under tired legs. Finally, it’s useful for preparing for hilly or windy race conditions, where your effort naturally shifts into this moderate, steady zone.
Tips for Effective Zone 3 Cycling
Use a power meter or heart rate monitor to keep your effort within Zone 3. This ensures you're not drifting too easy or pushing into threshold territory.
Maintain a steady cadence of 80–95 RPM to stay smooth and efficient throughout the session.
Fuel properly before and during workouts. Zone 3 efforts burn more glycogen than lower zones, so adequate nutrition helps sustain energy and performance.
Limit Zone 3 to 1–2 sessions per week. This intensity is effective but taxing — overdoing it can lead to fatigue or training stagnation.
Common Mistakes in Zone 3 Cycling
Riding Too Hard: Many athletes drift into Zone 4 without realizing — use a power meter or HR monitor to stay controlled.
Doing Too Much: More isn’t always better. Keep it to 1–2 sessions per week to avoid overreaching.
Neglecting Nutrition: Zone 3 burns more glycogen than Zone 2 — fuel before and during sessions.
Letting Cadence Drop: A low cadence increases fatigue. Keep spinning efficiently at 80–95 RPM.
Skipping Recovery: Always balance Zone 3 with true recovery rides or aerobic sessions in Zone 2.
Mini FAQ: Zone 3 Cycling for Triathletes
What is Zone 3 in cycling?
Zone 3 is your aerobic endurance zone—roughly 75–90% of your FTP (RPE 5–6). It’s steady, sustainable, and great for long efforts.
Why is Zone 3 important for triathletes?
It builds your aerobic base, improves fat utilisation, and teaches you to hold effort over race distances without burning out.
How often should I ride in Zone 3?
One to three sessions per week, especially during base and build phases. Long rides and tempo intervals often fall in this zone.
How do I know I’m in Zone 3 on the bike?
You should feel moderately hard—focused but comfortable. Use power (75–90% FTP) or RPE around 5–6. Set your zones with FLJUGA’s free FTP and Heart Rate Calculators.
Final Thoughts
Zone 3 cycling lives in that sweet spot — hard enough to challenge your system, but controlled enough to avoid burnout. For triathletes, it’s an essential intensity to build stamina, dial in race effort, and train the mind to stay steady when the pressure rises.
Use it wisely, fuel it well and you’ll feel the benefits on race day.
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.
