Reverse Brick Session: 30-Minute Run Into 60-Minute Bike

Session Overview

The reverse brick — running before cycling — trains your body to handle fatigue in a different order than a standard triathlon, and is a staple of duathlon preparation. It also develops your ability to find cycling rhythm when your legs are already loaded from running, making the transition between disciplines feel more natural. Expect your first 10–15 minutes on the bike to feel heavy; that’s exactly the point.

What You’ll Need

Warm-Up

No separate warm-up — the run phase begins at easy effort, which serves as your warm-up. Start the run at RPE 3 for the first 5 minutes before building.

Main Set

Two continuous phases with a timed T1-style transition between them.

  • Run phase — 30 minutes: Start at RPE 4, build to RPE 6 by minute 20. Ease to RPE 4 for the final 2 minutes to prepare for transition.
  • Transition: Swap shoes, clip in, roll out. Time yourself — aim for under 90 seconds.
  • Bike phase — 60 minutes: First 10 min at Zone 1–2 (RPE 3–4) — resist the urge to push hard, your legs need time to adapt. Next 35 min at Zone 2–3 (RPE 5–6). Final 15 min at Zone 3 (RPE 6–7) — finish strong.

Cool-Down (10 minutes)

Easy spin at Zone 1 back to your start point. Dismount and do 5 minutes of static stretching — quads, hip flexors, and calves take the most load in this session.

Coaching Notes

  • Expect cycling power or speed to be 5–8% below your normal figures for the first 15 minutes — this is the reverse brick effect and it’s a sign the session is working.
  • Great duathlon simulation: as your event approaches, match the distances to your race format (e.g. 5km run + 40km bike for standard duathlon).
  • Don’t fuel on the run phase — 30 minutes is short enough. Take gels or bars in the first 20 minutes of the bike phase.
  • Scale: reduce bike to 45 minutes if 90 minutes total feels too long early in training.

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.