75-Minute Sweet Spot Turbo Ride: Raise Your FTP Indoors

Session Overview

This 75-minute turbo trainer session targets your sweet spot — the training zone between tempo and threshold (88-93% of FTP) — where the biggest cycling fitness gains are made per hour of effort. It’s harder than a recovery ride but sustainable for longer blocks than pure threshold work, making it one of the most effective sessions in any triathlete’s indoor winter programme.

What You’ll Need

• Smart trainer or turbo trainer with power meter
• Heart rate monitor (use alongside power for zone validation)
• Cycling fan (essential — you’ll get very hot)
• Water bottle — aim for 500-750ml over the session
• Towel

Warm-Up (12 minutes)

Spin easy at 60-65% FTP for 8 minutes, building gradually. Then complete 3 x 30-second pick-ups at 90-95% FTP, with 90 seconds easy spinning between each. This primes your legs for the sustained effort ahead without accumulating fatigue.

Main Set

All sweet spot efforts should feel like a sustained 7/10 — uncomfortable but manageable, like the effort you’d hold for a 40km time trial. Cadence target is 85-95rpm throughout. If you don’t have a power meter, aim for Zone 4 heart rate or an effort you could sustain for up to an hour if required.

• 2 x 20 minutes at sweet spot (88-93% FTP), 5 minutes easy between — this is the core of the session. Hold your power steady; don’t go harder in the first 10 minutes and fade at the end.
• 1 x 8 minutes at threshold (95-105% FTP) after the 5-minute recovery — a harder effort to stress the aerobic system slightly beyond sweet spot. Focus on maintaining smooth pedal stroke under fatigue.

Cool-Down (10 minutes)

Drop to 55-60% FTP and spin easy for 10 minutes, gradually reducing cadence. If you have a heart rate monitor, aim to bring your HR below 120bpm before getting off the bike. Stretch your hip flexors and quads immediately after dismounting — these tighten significantly during extended aero or seated turbo positions.

Coaching Notes

• Sweet spot training works best when you’re consistent — 2 sessions per week of this type over 6-8 weeks will typically raise FTP by 5-10% in a trained cyclist.
• Don’t overcook it: if you find yourself unable to hold power in the second 20-minute effort, you either started too hard or did too much volume earlier in the week. Drop to the bottom of the sweet spot range (88%) and hold form.
• Easier version: Replace the 2 x 20 with 3 x 12 minutes at the same intensity. More rest, less sustained demand — suitable for riders building turbo fitness from a lower base.
• Harder version: Add a third 20-minute effort (90-minute total session) if you’re in a heavy training block and have a rest day tomorrow.