Sweet Spot Blocks: 3×15 Minutes at 88-93% FTP Turbo Session

Session Overview

Sweet spot training sits at 88-93% of FTP — the zone that delivers the greatest training stimulus per unit of fatigue. This 60-minute turbo session uses three 15-minute blocks at sweet spot intensity to build sustained power, improve your lactate clearance rate and raise your FTP over time. It is one of the most time-efficient sessions in a triathlete’s toolkit.

What You’ll Need

• Turbo trainer or smart trainer
• Power meter or ERG mode on smart trainer
• Fan — sweet spot generates significant heat
• At least 500ml fluid per block

Warm-Up (10 minutes)

10 minutes easy spinning at 55-60% FTP. Include 3×20-second spins at 100rpm+ to wake up the legs. Finish with 1 minute at 90% FTP to confirm your ERG mode is calibrated or your target power feels right.

Main Set

3 blocks of 15 minutes at 88-93% FTP with 5 minutes easy recovery spinning between each block:

• Block 1 (15 min at 88% FTP): Start conservatively — the first block should feel hard but sustainable
• Recovery 1 (5 min at 55% FTP): Keep spinning, stay on the bike, drink and recover
• Block 2 (15 min at 90% FTP): Slight step up — this is the bread and butter of the session
• Recovery 2 (5 min at 55% FTP): Focus on controlled breathing before the final block
• Block 3 (15 min at 93% FTP): The hardest block — hold form, resist the urge to let power drift

Cool-Down (5 minutes)

5 minutes easy spinning at 50-55% FTP. No heroics — the adaptation happens during recovery.

Coaching Notes

• Sweet spot is described as “comfortably hard” — RPE 7-7.5. You can speak in short sentences but not hold a conversation.
• Cadence: aim for 85-95rpm throughout. Grinding a low cadence at sweet spot will fatigue your muscles disproportionately.
• Make it easier: 2×15 minutes with 8 minutes recovery and stay at 88% throughout
• Make it harder: progress to 3×20 minutes or 4×15 minutes as the weeks build
• Weekly progression: add one 15-minute block every 2-3 weeks until you can complete 4x15min