90-Minute Ironman Race-Pace Bike: Power Holding Session

Session Overview

This 90-minute outdoor ride targets Ironman race power — a sustained, aerobic effort that builds the metabolic base for full-distance racing. Unlike threshold or interval work, this session is about spending time at the watts you’ll hold for 5–6 hours on race day, training your body to use fat efficiently and your mind to stay focused under sustained load.

What You’ll Need

• Road or TT bike in race setup
• Power meter (strongly recommended — this session is power-target specific)
• HR monitor
• 2 water bottles and race nutrition (gels, bars — use this as a nutrition practice ride)
• Relatively flat to rolling route with minimal traffic stops

Warm-Up (15 minutes)

15 minutes easy Zone 2 riding — conversational pace, 80–85 rpm. Don’t rush the warm-up. Long rides on cold muscles significantly increase injury risk. Let your hips and knees warm through before building into the main effort.

Main Set

60 minutes at Ironman race power. For most athletes this sits between 65–75% of FTP — often called “Zone 3” or upper Zone 2. This is distinctly aerobic — you should be breathing steadily but conversationally, with heart rate in Zone 3 (approximately 76–85% max HR). The challenge is discipline: many athletes ride this too hard and accumulate fatigue that derails their run training later in the week.

• Power target: 65–75% FTP (use 70% as a baseline if unsure)
• HR target: Zone 3, upper aerobic (76–85% max HR)
• Cadence: 85–90 rpm — never let it drop below 80
• Nutrition: Take on 60–90g carbohydrate per hour, and 500–750ml fluid — practice your race-day fuel strategy
• Aero position: Spend as much time as possible in your aero bars to build positional strength

Cool-Down (15 minutes)

15 minutes easy Zone 2, reducing to Zone 1 in the final 5 minutes. Spin freely and use this time to mentally review your nutrition intake and how the effort felt. Note your average power, normalised power, and whether you stayed within your target range.

Coaching Notes

• This is NOT a hard ride. If you’re sweating heavily in the first 20 minutes or your HR is climbing past Zone 3, slow down.
• The Ironman bike leg is won by discipline, not heroics. Training at race watts builds the correct physiological adaptations — going harder than race pace during training teaches your body to do the wrong thing.
• Follow this ride with a short 10–20 minute easy run to simulate the bike-to-run transition and reinforce the muscular patterns needed after sustained cycling.
• Do this session 2–3 times per week in your Ironman build phase, progressively extending to 2 hours and beyond as your race approaches.