Plan Overview
This plan prepares you for middle distance triathlon — a 1.9km swim, 90km bike, and 21.1km run. Built around heart rate and power, every session carries precise targets tied to your individual training zones, giving you an objective way to execute the right effort on the right day. Middle distance tests endurance, pacing, and mental resilience — long enough that mistakes in effort management cost you, short enough that you cannot afford to be underdone.
Who This Plan Is For
This plan assumes a solid aerobic base already in place: continuous swimming for 40+ minutes, 2–3 hours on the bike, and a long run of 75+ minutes in your recent training. You'll need a heart rate monitor and a power meter (or smart trainer), with threshold heart rate and FTP established or tested in week one. Not there yet? Build through our Sprint or Olympic plans first.
Starting without adequate base fitness raises your risk of injury, illness, and being under-prepared on race day. Eight weeks won't build fitness from scratch — but it will sharpen and peak the fitness you already have.
What the Plan Covers
Your base and build phases come from your longer-term training. This plan covers the final two phases:
Competition Prep — race-pace efforts, nutrition and pacing strategy, transition practice, and discipline-specific work for the demands of 1.9km/90km/21.1km. Every session carries a heart rate and/or power target, removing the guesswork from pacing — a skill as valuable in training as on race day.
Taper — a managed drop in volume that lets your body absorb months of work. The taper is not rest, it's a precision tool. Doing too much in the final 10 days is one of the most damaging middle distance mistakes.
These 8 weeks convert fitness into race-readiness. Trust the work done, respect the taper, execute with confidence.
Understanding Heart Rate & Power
Heart rate, based on lactate threshold heart rate (LTHR), shows how your body responds to workload in real time — accounting for heat, fatigue and cumulative stress. Power, based on Functional Threshold Power (FTP), shows exactly how much work you're producing on the bike, independent of conditions.
Together they keep you honest: power stops you overcooking the bike leg, heart rate flags when that effort is costing more than it should — an early warning your run is about to fall apart. Training and racing by these numbers means far less chance of blowing up on the bike and dragging a dead run leg behind you.
Medical Disclaimer
This plan is informational only and does not constitute medical advice. Middle distance triathlon places significant demands on the cardiovascular and musculoskeletal systems. Consult a qualified medical professional before beginning this or any high-intensity training programme, particularly with pre-existing health conditions. The Tri Project accepts no liability for injury or adverse health outcomes. You train at your own risk. If you experience chest pain, dizziness, or disproportionate breathlessness, stop immediately and seek medical attention.
A Final Word
Eight weeks. Three disciplines. One finish line. Trust your numbers, trust the process, respect the taper. We will see you there.
Hello! I’m Bex, an endurance coach specialising in triathlon, with over a decade of experience coaching in high performance environments.
During my years at British and Triathlon Scotland I coached multiple athletes and teams to Paralympic and Commonwealth medals. Alongside that I have coached multiple pro and age group athletes to 70.3 and Ironman podiums. My mission is to support endurance athletes to reach their physical potential in sport and enjoy the process along the way.