Stacked Threes
70 min · 62-75 TSS · IF 0.75 · 108-115% FTP · Zone 5+ (VO2max)
What this workout does
Six three-minute efforts ridden slightly harder than classic VO2max intervals. The shorter reps let you hit a higher target and still finish the set - stacking up quality minutes at maximum oxygen uptake.
Shorter reps let you ride at 108-115% FTP - harder than four or five-minute efforts allow - while the set still accumulates around eighteen minutes near maximal oxygen uptake. The higher intensity recruits more muscle and adds a mild anaerobic overlay. Slot it mid-build as a harder alternative to classic VO2max intervals.
How to ride it
Indoor / trainer
Warm up 15min with 3 short openers. 6x3min at 108-115% FTP with 3min easy between. Cool down 15min. The last two reps should hurt - that is where the gains are.
Outside
Use a 3-4min climb or a quiet stretch of road. Go out at 108-115% FTP - hard from the first pedal stroke, legs burning by the 2min mark - and soft-pedal for 3min between efforts.
Workout structure (70 min)
- Warm-up 15m 55% 3x - Opener 30s 110% - 1m 30s 55% 6x - Effort 3m 112% - 3m 55% - Cool-down 15m 55%
Targets are a percentage of FTP. This is the same shorthand the free workout builder understands — paste it there to edit any step, or download the workout for Zwift, Garmin or any smart trainer.
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