High intensity vs Low intensity training for long cycling races.

When preparing for long mountain or gravel biking events, both interval training (high-intensity interval training, or HIIT) and low-intensity training (LIT or Zone 2 endurance training) have unique roles to play. Here's a comparison to help you understand the pros and cons of each approach:

🔁 Interval Training (HIIT / VO2 Max / Threshold Intervals)

✅ Pros

• Improves aerobic capacity quickly: Boosts your VO2 max and lactate threshold — crucial for steep climbs and technical sections.

• Builds power and speed: Short bursts mimic the surges needed in mountain biking (e.g., steep pitches, overtaking).

• Time efficient: Great results in less training time, ideal if you’re busy.

• Increases fatigue resistance: Helps you push harder later in the event.

❌ Cons

• More taxing on recovery: Can lead to burnout or injury if overused.

• Requires more structure: Needs precise pacing and monitoring (heart rate, power).

• Not enough on its own for endurance: Without a solid aerobic base, you'll fade over long distances.

• Hard to do on technical trails: Best done on predictable terrain or indoor trainer.

🚴‍♂️ Low-Intensity Training (Zone 2 / Endurance Rides)

✅ Pros

• Builds strong aerobic base: Crucial for multi-hour efforts — improves fat metabolism and overall efficiency.

• Promotes recovery: Less stressful on the body; you can do it frequently.

• Improves endurance and pacing: Teaches you to ride steady, conserve energy, and manage terrain transitions.

• More enjoyable and social: Can be done on trails with friends or solo without extreme effort.

❌ Cons

• Takes time: You need long sessions (2–5+ hours) to get the benefits.

• Slower to show results: Gains are gradual compared to HIIT.

• Lacks intensity for racing: Doesn’t train high-end power or anaerobic capacity.

• Can feel boring: Mentally less engaging for some riders.

🏁 Best Strategy for Long MTB Events

For events like long-distance mountain or gravel bike races (e.g., 3–6+ hours), the ideal approach combines both:

Training Phase	Focus
Base Phase (8–12 weeks)	80–90% LIT, 10–20% intervals (Zone 3) – build endurance
Build Phase	Increase interval volume (threshold/VO2), maintain LIT
Peak/Taper	Sharpen with short, intense intervals; reduce volume

Rule of Thumb:

80/20 rule — 80% of your weekly time in low intensity, 20% in high intensity is a widely effective balance.

🧠 Summary

Feature	Interval Training	Low-Intensity Training
Time Efficiency	✅	❌ (Needs more time)
Builds Aerobic Base	⚠️ (some benefit)	✅ (core benefit)
Improves Climbing Power	✅	⚠️ (only over time)
Recovery Friendly	❌	✅
Specific to Race Surges	✅	❌