70.3 Race Watts: 4×30 Minute Power Blocks Turbo Session

Session Overview

A structured 70.3-specific turbo session using four 30-minute blocks at IRONMAN 70.3 race power. This session teaches your body to sustain the precise wattage you need for 90km at race effort, while building the fatigue resistance that separates athletes who run well off the bike from those who shuffle.

What You’ll Need

  • Smart turbo trainer (ERG mode recommended) or power meter
  • Bike in race position
  • Hydration (600ml per 30-min block minimum)
  • Fan — this session generates significant heat load
  • 70.3 race nutrition (gels or chews) to practise fuelling at effort

Warm-Up — 15 min

  • 10 min easy spin Z2, cadence 90-95rpm
  • 3×1 min at Z3, 1 min easy between
  • 2 min easy spin before main set

Main Set: 4×30 min at 70.3 Race Power

70.3 race power is typically 75-85% of FTP for well-trained athletes. If your FTP is 250W, target 188-212W for each block.

  • Block 1 (0-30 min): hold target watts, cadence 85-90rpm — feel should be “comfortably hard”
  • Rest 5 min: easy spin, sip 200ml fluid, take a gel if using race nutrition
  • Block 2 (35-65 min): same target watts — note HR creep; should be stable after 10 min
  • Rest 5 min: easy spin, hydrate
  • Block 3 (70-100 min): watts unchanged — this is where conditioning separates athletes; hold form
  • Rest 5 min: easy spin, hydrate, take second gel
  • Block 4 (105-135 min): final push; if you’ve paced correctly you should be able to hold or slightly increase watts in the final 5 minutes

Cool-Down — 10 min

  • Easy spin Z1, cadence free
  • Stretch quads, hip flexors and calves immediately after

Coaching Notes

  • Total ride time: approximately 2h15 including warm-up, rest periods and cool-down
  • If you cannot complete Block 3 at target power, your FTP estimate is too high — reduce by 5% and retest
  • Practise your race nutrition during this session — gels every 45 min, consistent hydration
  • Complete this session 2-3 times in the 6 weeks before your 70.3; taper begins 10-14 days out
  • Pair with an easy 20-min jog immediately post-session once per month to simulate race-day transition fatigue

Training at your own risk. The information provided is for general guidance only and is not a substitute for professional medical advice. Please consult a doctor before starting any new exercise programme, especially if you have any pre-existing health conditions.