Turbo Trainer: 4×8-Minute FTP Progression Intervals

Session Overview

Four 8-minute FTP intervals on the turbo is a highly efficient 60-minute session that builds sustained power and prepares your body for the effort required in a triathlon bike leg. It’s ideal for intermediate riders looking to raise their FTP without the fatigue of longer threshold blocks — and it fits comfortably into a busy training week.

What You’ll Need

• Smart turbo trainer or resistance trainer
• Power meter (strongly recommended) or heart rate monitor
• Fan — essential at FTP effort for cooling and performance
• Water (minimum 750ml at this intensity)
• Towel

Warm-Up (12 minutes)

12 minutes building from Zone 1 to Zone 3: 5 minutes easy spin, then 4 minutes at 60–70% FTP, finishing with 3 minutes at 75–85% FTP. Add 2 × 15-second spin-ups to 100+ rpm to prime your neuromuscular system before the main set.

Main Set

4 × 8 minutes at FTP (95–105% FTP, RPE 8), with 3 minutes of easy Zone 1–2 spinning between each interval. Total main set time: approximately 44 minutes.

• Interval 1 (8 min @ FTP): Find your rhythm — don’t go out too hard. Settle into your target power and maintain cadence at 88–95 rpm.
• Recovery (3 min, Zone 1): Drop to easy spin, take on fluids, flush lactic acid. Stay pedalling — don’t coast.
• Interval 2 (8 min @ FTP): This one starts to bite. Hold form — avoid rocking in the saddle and keep cadence up.
• Recovery (3 min): Same as above. Control your breathing before the next effort.
• Interval 3 (8 min @ FTP): Mental commitment required. Focus on one minute at a time. RPE may feel like 9 even at the same wattage.
• Recovery (3 min): Big controlled breaths — one more to go.
• Interval 4 (8 min @ FTP): Leave everything on the turbo. If power remains stable and you have something left, push the final 2 minutes by 5–10W.

Cool-Down (8 minutes)

8 minutes easy spinning at under 55% FTP, gradually reducing cadence. Don’t jump off the bike immediately — a proper cool-down prevents light-headedness and begins the lactate clearance process.

Coaching Notes

• If your FTP was set more than 6 weeks ago, consider a ramp test first — stale numbers lead to undertraining or blowing up mid-session.
• Target 88–95 rpm cadence throughout — too low and you over-recruit muscle mass; too high and breathing escalates unnecessarily.
• Scale down: reduce to 3 × 8 minutes, or use 3 × 6 minutes if returning from a training break.
• Scale up: extend to 4 × 10 minutes, or reduce recovery to 2 minutes once all four 8-minute intervals feel controlled and consistent.