Over-Under Threshold Intervals: The Secret Weapon to Break Through FTP Plateaus

What Are Over-Under Intervals?

Over-Under (O/U) intervals are an advanced training method that alternates above and below threshold power. During the workout, you repeatedly switch between slightly below FTP (the Under segment) and slightly above FTP (the Over segment), forcing your body to sustain high power output in a dynamic balance of continuous lactate accumulation and clearance.

Basic Parameters

• Under segment: 92%-97% of FTP (HR: 95%-99% of LTHR, RPE 6-7/10)
• Over segment: 103%-110% of FTP (HR: 100%-105% of LTHR, RPE 8-9/10)
• Overall feel: More painful than steady threshold training, because the Over segment produces significant lactate accumulation while the Under segment intensity is insufficient for full recovery

Why Are Over-Unders So Effective for Breaking Through FTP?

1. Lactate Tolerance and Clearance Capacity

During the Over segment, your power exceeds FTP, lactate production outpaces clearance, and blood lactate concentration rises rapidly. When you switch to the Under segment, power drops slightly below FTP, lactate clearance slightly exceeds production, but recovery is slow. This repeated lactate “tide” trains your body to buffer and metabolize lactate more efficiently.

2. Mental Toughness

Race pacing is rarely steady—you experience climbs, surges, and headwinds. Over-Under training gets you accustomed to pushing harder when you’re “already suffering,” building the mental fortitude to keep going in competition.

3. FTP Improvement Efficiency

Research shows that variable-intensity training near threshold produces a greater training stimulus than steady threshold work, due to the adaptive effects of briefly crossing the threshold during the Over segments.

6 Over-Under Workout Designs

Workout 1: Beginner 2-Minute Alternation (Total Duration: 70 Minutes)

Suitable for riders trying O/U training for the first time:

• Warm-up: 20 minutes progressive (including 3 × 20-second spin-ups @ 110% FTP)
• Main set: 3 × 8 minutes (within each 8-minute block)
  • 2 minutes Under @ 93% FTP → 2 minutes Over @ 105% FTP → repeat once
  • Recovery between sets: 5 minutes @ 55% FTP
• Cool-down: 10 minutes

Example: FTP 250W → Under 233W / Over 263W

Workout 2: Classic 3/1 Structure (Total Duration: 80 Minutes)

The most common O/U format, 3 minutes Under + 1 minute Over:

• Warm-up: 20 minutes
• Main set: 3 × 12 minutes (within each 12-minute block)
  • 3 minutes Under @ 95% FTP → 1 minute Over @ 108% FTP → repeat three times
  • Recovery between sets: 6 minutes @ 50% FTP
• Cool-down: 10 minutes

Example: FTP 250W → Under 238W / Over 270W

Workout 3: Long-Distance Race Preparation (Total Duration: 95 Minutes)

Simulates pace changes in long road races:

• Warm-up: 20 minutes
• Main set: 2 × 20 minutes
  • Within each set: 4 minutes Under @ 95% FTP → 1 minute Over @ 107% FTP → repeat four times
  • Recovery between sets: 8 minutes @ 50% FTP
• Cool-down: 10 minutes

HR guidance: Heart rate during the Under segment should stay at 96%-99% of LTHR; during the Over segment, HR may slightly exceed LTHR

Workout 4: High-Intensity 2/2 Balanced Format (Total Duration: 75 Minutes)

Equal-length Over and Under segments for increased intensity:

• Warm-up: 15 minutes
• Main set: 4 × 8 minutes
  • 2 minutes Under @ 95% FTP → 2 minutes Over @ 106% FTP → repeat once
  • Recovery between sets: 4 minutes @ 50% FTP
• Cool-down: 10 minutes

Workout 5: Progressive Over Intensity (Total Duration: 78 Minutes)

Increasing Over-segment intensity with each set:

• Warm-up: 18 minutes
• Main set:
  • Set 1 (10 minutes): 3 min @ 94% → 2 min @ 103% → 3 min @ 94% → 2 min @ 103% → 5 min recovery
  • Set 2 (10 minutes): 3 min @ 94% → 2 min @ 106% → 3 min @ 94% → 2 min @ 106% → 5 min recovery
  • Set 3 (10 minutes): 3 min @ 94% → 2 min @ 110% → 3 min @ 94% → 2 min @ 110%
• Cool-down: 10 minutes

Workout 6: Race Simulation O/U (Total Duration: 90 Minutes)

Simulates the end-of-lap surges in criterium racing:

• Warm-up: 20 minutes
• Main set: 5 × 6-minute “simulated laps”
  • 4 minutes Under @ 96% FTP (simulating cruising)
  • 30 seconds Over @ 115% FTP (simulating a position-fighting surge)
  • 1.5 minutes Under @ 93% FTP (simulating recovery)
  • Recovery between sets: 4 minutes @ 55% FTP
• Cool-down: 10 minutes

Cadence Strategy

Key Execution Points and Common Mistakes

Point 1: The Under Segment Is Not Rest

The most common mistake is treating the Under segment as recovery and letting power drop below 85% FTP. Under-segment power should be maintained at 92%-97% FTP—this is still a fairly high intensity, just relatively easier compared to the Over segment.

Point 2: Don’t Surge in the Over Segment

Another common mistake is going too hard in the Over segment, exceeding 110% FTP. This will prevent you from completing the remaining sets. The purpose of the Over segment is to briefly cross the threshold, not to sprint all-out.

Point 3: Pay Attention to Smooth Transitions

Power transitions should be completed within 5-10 seconds, avoiding sudden power spikes or slow ramping. Practice smooth switching between Under and Over—this is also an important pedaling skill.

Point 4: Heart Rate Will Keep Climbing

During O/U training, the heart rate peak of each Over segment will be higher than the previous one, and HR during the Under segment won’t fully drop back down. By the end of the set, HR may be very close to HRmax. This is normal and indicates the training is working.

Weekly Scheduling Recommendations

• 1-2 O/U sessions per week
• Do not schedule VO2max training and O/U training on the same day
• The day after an O/U session should be a recovery ride or endurance ride
• Stop O/U training 3-4 days before an FTP test to ensure full recovery

Progress Indicators

1. Ability to complete more sets: Progressing from 3 sets to 4-5 sets
2. Higher Over-segment power: Progressing from 105% to 108-110% of FTP
3. Faster heart rate recovery: HR drops more quickly after the Under segment begins
4. Lower RPE: Feels less painful at the same power output

Summary

Over-Under intervals are one of the most effective training methods for breaking through an FTP plateau. They simulate the real intensity fluctuations of racing while strengthening your performance near threshold from both physiological and psychological perspectives. Start with the beginner workout and gradually increase the number of sets and Over-segment intensity—you’ll notice significant improvements in your FTP test performance.

Related Reading

• Over-Under Training: Lactate Clearance Workouts Alternating 5% Above and Below FTP
• Cycling Lactate Threshold Training: Sweet Spot 88–93% FTP Interval Design
• FTP Improvement Strategies: Annual Periodization of Sweet Spot, Over-Unders, and VO2max Intervals
• Lactate Threshold Intervals: Periodized Application of Sweet Spot Training (88–93% FTP)