2x20 Threshold
Threshold workoutAdvanced76 minTSS 92IF 0.85
Two 20-minute efforts just under FTP: the session that has built more time-trial engines than any other.
- Z1 Active recovery · 27:12
- Z2 Endurance · 5:48
- Z3 Tempo · 3:00
- Z4 Threshold · 40:00
Intervals
| Sets | Step | Time | Target (FTP) |
|---|---|---|---|
| Warm-up | 10 min | 45–70% | |
| Opener | 3 min | 90% | |
| Easy | 3 min | 55% | |
| 2 × | Threshold | 20 min | 97% |
| Recovery | 5 min | 55% | |
| Cool-down | 10 min | 55–40% |
Why 2x20 works
Riding close to FTP for long, unbroken blocks raises the power you can sustain before fatigue builds quickly. Splitting 40 minutes into two blocks makes the session repeatable without the cost of a full race effort.
How to ride it
At 97% of FTP the first ten minutes feel steady and the last five feel hard. If you cannot finish the second interval, your FTP may be set too high, or you came in tired. Drop the target to 94–95% and try again after a rest day.
Fans and fluids matter more than usual: threshold work indoors produces a lot of heat.
Progression
Next steps are 2x25, then 3x20, before you raise the percentage. Keep it to one threshold session a week alongside other intensity.
Questions
What is a 2x20 workout?
Two 20-minute intervals close to threshold, usually 95–100% of FTP, with a short recovery between them.
What if I cannot finish the second interval?
Lower the target to 94–95% of FTP next time, and check that your FTP is up to date.
More workouts
VO2max 5x4
VO2max workout · Advanced
Stress: 87 Intensity: 0.87
30/30 Intervals
VO2max workout · Intermediate
Stress: 57 Intensity: 0.77
Tempo 3x20
Tempo workout · Intermediate
Stress: 89 Intensity: 0.77