How to Read and Use a Triathlon Training Plan
You have downloaded a training plan, opened it up and immediately been confronted with zone numbers, acronyms and percentages you do not fully understand. You are not alone. Triathlon training plans use a specific language that can be confusing at first — but once you know the key terms, every session makes sense and you can execute your training with confidence.
Understanding Training Zones
Most triathlon plans use a 5 or 7-zone system based on your effort level, usually expressed as a percentage of your threshold heart rate, FTP (functional threshold power on the bike) or threshold pace (for running). Zone 1 is very easy recovery effort; zone 5 or 7 is maximum sprint effort. The most important zones for endurance training are:
- Zone 2 — Easy aerobic effort. You can hold a full conversation. This is where you build your aerobic engine and spend the majority of your training time.
- Zone 3 / Sweet Spot — Comfortably hard. You can speak in short sentences. Used for tempo and sustained efforts.
- Zone 4 / Threshold — Hard. You can manage a few words between breaths. This is your lactate threshold pace and is used for interval work.
- Zone 5 / VO2max — Very hard. Not sustainable for more than a few minutes. Used for short, high-intensity intervals.
Common Training Plan Terms Explained
- FTP (Functional Threshold Power) — The highest average power you can sustain for one hour on the bike. Used as the anchor for all cycling zone calculations.
- CSS (Critical Swim Speed) — Your swimming threshold pace, calculated from a 400m and 200m time trial. Used to set swim interval target paces.
- Brick — A session combining two disciplines back to back, most commonly bike then run, to train your legs to adapt to the transition.
- Tempo — Sustained effort at zone 3, harder than easy but not full threshold. Builds aerobic capacity and teaches pacing.
- Intervals — Repeated efforts at a specified intensity with recovery between them. The effort duration and recovery ratio define the training effect.
- RPE (Rate of Perceived Exertion) — A subjective 1–10 scale of how hard you feel you are working. Used when you do not have a heart rate monitor or power meter.
How to Set Your Training Zones
Before following any plan based on zones, you need to establish your personal thresholds. For the bike, perform an FTP test (20 minutes at maximum sustainable effort, then multiply average power by 0.95). For running, use a 30-minute time trial or your most recent race pace at 10km. For swimming, do a 400m and 200m time trial and input the results into a CSS calculator. Once you have your threshold numbers, multiply them by the zone percentages your plan specifies. Reassess every 6–8 weeks as your fitness improves.
When to Adjust the Plan
A training plan is a guide, not a contract. If you are ill, genuinely fatigued or recovering from a minor injury, drop the intensity to zone 2 or skip the session entirely. Missing one session is far better than grinding through it and adding two weeks of injury recovery. Look at the overall structure of your plan rather than fixating on each individual day — the cumulative load across weeks is what drives adaptation, not a single session.
